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D
RESULTS AND
DISCUSSION
142
4. RESULTS AND DISCUSSION
India is experiencing an epidemic of type 2 diabetes mellitus and cardiovascular
diseases, attributed to epidemiological and nutrition transition occurring in urban
and rural areas though at faster levels in urban settings. Nutrition transition is
marked by a change in the food supplies and consumption, especially the shift
from traditional Indian home-cooked foods to more processed foods which are
rich in sugar and fats – particularly trans fatty acids. Recent evidence shows that
specific fatty acids affect cell metabolism, modifying the balance between fatty
acid oxidation and lipogenesis.
There is a significant and growing body of evidence linking trans fatty acids to
coronary heart diseases indicating TFA may do even more harm than saturated
fats. Metabolic studies, for instance, show that trans fatty acids increase blood
levels of LDL cholesterol and decrease blood levels of HDL cholesterol. Both
effects are strongly associated with increased coronary heart diseases. Saturated
fats are thought to be less damaging because they elevate both the “bad” and
“good” types of cholesterol. Epidemiological data also point to a greater risk of
coronary heart diseases from increases in dietary TFA than from increases in
dietary saturated fats. Further, apart from cardiovascular diseases, studies also
indicate that TFA consumption has been positively associated with ovulatory
infertility, complications during pregnancy, cognitive decline, certain types of
cancers, asthma and allergies as well as adverse effects on foetal and infant
development.
In view of these adverse effects of trans fatty acids on human health, governments
in the developed countries have taken stringent actions by adopting strict policies
to curb trans fats from the food supply. However, in India not much work has
been done in this regard; therefore, the present study has been carried out to
estimate the TFA content of fats/ oils, study the formation of TFA in re-heated
oils as well as analyzing the TFA content of some fried/ baked food items and
dairy products commonly consumed in Indian households. Using the laboratory
143
analyzed values of TFA, the study further aimed to assess the dietary intake of
TFA by women belonging to middle/ upper middle income group (MIG/ UMIG)
families from Delhi and study the effect of TFA on anthropometric measurements,
body composition, clinical and biochemical parameters. The present study has two
components field work and the laboratory analysis. The result of the preliminary
data from field work served as the basis for initiating and carrying out the
laboratory analysis. While the result outcomes of laboratory analysis helped in
understanding the adverse effects of TFA on the health status of the population
under study. Thus, the two components of the study, field work and laboratory
analysis complemented each other and helped in arriving at the study results and
conclusions. The study was approved by human ethics committees of Institute of
Home Economics and Fortis hospital Vasant Kunj, New Delhi.
The field work comprised of gathering the preliminary data on commonly
consumed fats/ oils, deep fat frying practices and knowledge regarding TFA as
well as assessing the TFA intake by women belonging to MIG/ UMIG families.
For this, 402 female school teachers were enrolled from six schools located in
different parts of Delhi and the necessary permission was obtained from the
school authorities. After obtaining written informed consent, data were gathered
on their socio demographic profile, medical history, dietary intake, anthropometric
measurements, body composition, clinical and biochemical parameters. An
attempt has been made to study the effect of TFA intake of the subjects with their
anthropometric measurements, body composition, clinical and biochemical
parameters.
In addition a small preliminary survey was also carried out among chefs/ cooks of
select food outlets from Delhi/ NCR, where the necessary data pertaining to their
frying practices/ type of oil used and awareness regarding TFA were gathered.
The laboratory analysis involved estimating the TFA content of fats/ oils, as well
as studying the formation of TFA in fats/ oils subjected to varying temperatures
with or without frying the food items. Further the study also included analysis of
144
the TFA content of certain fried/ baked food items and dairy products commonly
consumed in Indian households. For the purpose of heating edible fats/ oils, due
permission was obtained from the Institute of Home Economics (University of
Delhi), Hauz Khas New Delhi to avail of the facilities available at the Food
Science laboratory. After obtaining the necessary permission from the Foundation
for Innovation and Technology Transfer (FITR), Indian Institute of Technology
(IIT) Delhi, the quantitative analysis of Trans Fatty Acids (TFA) content of select
fats/ oils, fried/ baked food items and dairy products was carried out at the
Department of Chemical Engineering, Indian Institute of Technology (IIT) Delhi.
For clarity and better understanding of the study outcomes, the results are being
discussed as below:
Preliminary data from field work
− Data relating to school teachers
− Data gathered from cooks/ chefs working in restaurants/ fast
food joints/ road side vendors/ bakery shops
Laboratory analysis
− Fatty acid profile including TFA content of edible fats/ oils
− TFA content of select edible fats/ oils both before and after
heating/ frying at varying temperatures
− Fatty acid profile including TFA content of commonly
consumed fried/ baked/ dairy food items
Composite use of the Laboratory Analysis and Field Work Data
− Dietary Intake with Special reference to Trans fatty Acids
− Anthropometry, body composition, clinical and biochemical
parameters
− TFA intake vis cardio-metabolic risk factors
4.I FIELD SURVEY; PRELIMINARY DATA
For this purpose 400 female school teachers were proposed to be enrolled from
schools located in different parts of Delhi. After obtaining necessary permissions,
initially five schools were approached; however, in order to have the necessary
145
sample size (n = 400), one more school was approached. 417 teachers were found
to be eligible for participation in the study. Out of these 417 teachers, only 406
provided their consent. Although 406 teachers were enrolled in the study, the
dietary data could not be gathered from four of them, as two teachers got
transferred to other schools, one went on maternity leave and one had left the job
due to some personal reason. Thus, the total sample comprised of 402 school
teachers. For the biochemical parameters, it was proposed to collect the blood
samples from one-third of the enrolled subjects (n=135) from 2 schools. However,
the targeted number could not be achieved, therefore one more school (from the
six schools selected) was approached for blood samples. Thus, the final sample
size for biochemical parameters’ estimation is 162 subjects. Once the teacher
expressed her interest in participating in the study and provided consent, the
preliminary survey questionnaire cum interview schedule was administered. The
details of this questionnaire cum interview schedule included socio demographic
profile and required the subjects to mark the commonly consumed fats/ oils/ fried/
baked/ dairy and other food items and deep fat frying practices adopted at home.
The commonly consumed fats/ oils and food items were then identified from the
choices marked by the subjects in their preliminary questionnaire. These were the
basis for carrying out the laboratory analysis and were then analysed for their fatty
acid profile (saturated, unsaturated and trans fatty acids) at the department of
Chemical Engineering Indian Institute of Technology, Delhi.
4.I.1 SOCIO DEMOGRAPHIC PROFILE
Age, Marital Status and Religion: Of the total 402 subjects enrolled,
nearly half (52%) were in the age range of 35 to less than 45 years (mean
age 41.6 ± 8.6 yrs.). A little more than one-fourth of the total subjects
(26.7%) were aged between 27 to less than 35 years and 21.3 per cent aged
between 45 to 60 years (Table 4.I.1). Majority of the subjects were Hindu
(76.8%) followed by Sikhs (12.7%), Muslims (6.7%) and Christians
(3.7%). Further, majority of the subjects were married (85.6%) while
remaining were either unmarried (11.2%), separated (~1%) or widowed
(2.2%).
146
Educational Qualifications: Since all the subjects under study were
female school teachers, their educational status was quite high. Detailed
survey regarding the educational qualifications among the subjects
revealed that all the subjects were at least graduates with bachelors in
education (B. Ed) which is a mandatory qualification for teachers. 40 per
cent were post-graduates, almost 7.2 per cent of the total subjects had
double post-graduation, while around 4 per cent possessed Ph D degree.
Family type and family size: On the basis of size or structure and the
depth of generations, family can be classified into three main types; (i)
Nuclear or the single unit family, (ii) Joint family and (iii) extended
family. Nearly three-fourth of the subjects (78.6%) were from nuclear
families while remaining were either from joint families (19.9%) or from
extended families (n=6; 1.5%). The total number of family members
ranged between 2 - 10 members with average family size being 4.1 ± 1.8
members in a family. The average number of adults per family was 2.6 ±
1.2 ranging between 1 to 8 members, while the average number of children
(<18 years) per family was 1.4 ± 0.89 ranging between 0 to 3 children.
Income and Socioeconomic Status: The average monthly income of the
subjects was ` 39,838.3ranging between ` 28,000 to ` 55,000, with
majority of the subjects (73.1%) earning between ` 35000 - ` 45000.
While the average monthly income of the family was ` 94, 4450 (` 60,000
to ` 1,65,000).
4.I.2 DIET RELATED DATA
Some amount of information was also gathered from the subjects regarding
cooking practices. These included type and amount of fat used, fried food items
prepared, consumption of fried/ baked and dairy foods and deep fat frying
practices adopted (amount of fat/ oil taken for frying, duration of heating fat/ oil
147
before frying/ its re-use and storage of oil after frying etc.). This information
played as the foundation for the laboratory analysis component of the study.
4.I.2.1 Cooking Practices and Commonly Consumed Fats/ Oils
Data gathered indicate that the subjects were consuming varied type of fats and
oils. It was noted that in general three or more fats/ oils were being used by most
of the subjects for the purpose of cooking (sautéing and baghaar), frying,
shortening, baking and as sandwich spread. Traditional usage, cost and even
“Health Claims” were the major determinants while making the choices regarding
type and brand of the cooking/ frying medium.
Subjects reported the use of a variety of fats/ oils, with all of them consuming
mustard oil of different brands like Panghat, Kachhi ghani, Kannodia etc. mainly
for preparation of specific vegetables. Groundnut oil was consumed by 14.7 per
cent of the subjects both for the purpose of cooking as well as frying; the major
brand being Fortune and Dhara.
Further, it was seen that soybean oil was consumed by 30.5 per cent of the
subjects; the commonly used brands included Fortune, Nature fresh, Dhara etc.,
while 15.9 per cent were using sunflower oil (Nature fresh, Fortune, Sundrop
etc.). A little more than one-fourth of the subjects (26.9%) were also using refined
blended oils with major brands being Saffola Gold, Sundrop Heart and Saffola
Tasty. Use of Olive and Canola was also seen in 24.1 per cent and 7.7 per cent of
the subjects respectively. Olive oil was also reportedly being used for baking by
4.7 per cent subjects. Desi ghee was being used by all the subjects mainly for the
purpose of baghaar, however, some even used it for frying (~4%) and shortening
(62%). Rice bran oil (~4%), Palmolein oil (1.7%) and coconut oil (~1%) were
reportedly being consumed by only a small percentage of the subjects.
148
Table 4.I.1: Distribution of the subjects by their socio-demographic profile
Surprisingly Vanaspati was, also being consumed by 7.2 per cent of the subjects
mainly for the purpose of frying, however some even used it for cooking
Particulars N (%) Particulars N (%)
Age Average Family Size 4.2 ± 1.3
Average Age 41.6 ± 8.6 ≤3 114 (28.4)
<35 years 107 (26.7) 4-5 254 (63.2)
35 - <45 years 209 (52.0) 6-7 28 (7.0)
45 - 60 years 86 (21.3) ≥ 8 6 (1.6)
Educational Qualifications
Marital Status Graduation (BA/ B.Sc.) + B. Ed
(Basic qualification) 402 (100)
Married 344 (85.6) Post-Graduation (MA/ M.Sc.) + B. Ed. 161 (40.0)
Unmarried 45 (11.2) Double Post-Graduation + B. Ed. 29 (7.2)
Divorcee/
Separated 9 (2.2) Ph D 16 (4.0)
Widowed 4 (1.0) Socio Economic status
MIG 207 (51.5)
Religion UMIG 195 (48.5)
Hindu 309 (76.9) Subject’s Monthly Income
Christian 15 (3.7) ` 25000 - <` 35000 42 (10.5)
Muslim 27 (6.7) ` 35000 - <` 45000 294 (73.1)
Sikh 51 (12.7) ` 45000 - <` 55000 56 (13.9)
≥ ` Rs 55000 10 (2.5)
Type of Family Monthly Income of the Family
Nuclear 316 (78.6) ` Rs 50000 - <` 75000 28 (7.0)
Joint 80 (19.9) ` Rs 75000 - <` 100000 237 (58.9)
Extended 6 (1.5)
≥ ` Rs 100000 137 (34.1)
149
purposes (1.5%); the brands included Rath, Dalda, Panghat and Gagan. This
clearly indicates that Vanaspati the so called “Bad fat” is still being consumed by
the population at large, even in the middle and upper middle income groups, who
have proper formal education and assess to all kinds of nutritional and health
related information.
Figure 4.I.1: Distribution of subjects based on reported use of fats/ oils
Among the other fats being used, 89.3 per cent subjects reported the use of
yellow pasteurized butter as bread spread, or for the purpose of shallow frying
(16.9%) and even baking (20.1%), the major brands were Amul and Britannia.
Around 27.1 per cent subjects also reported the use of White butter (either
homemade or purchased from local bakery). Interestingly Peanut butter (~7%)
and vegetable oil based sandwich spread (21.8%) were also being used by the
subjects, as they considered it as a “healthy replacement” for butter.
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Per cen
t (
%)
150
Table 4.I.2: Reportedly used fats/ oils for various culinary practices
(Multiple Responses)
Commonly
Used Fats/
Oils
Reported
Usage
Culinary Practices (%)
N % Cooki
ng
Fryin
g
Shorteni
ng
Bakin
g
As
Spread
on /
Bread/ chapati/
parantha
Mustard oil 402 100.0 100 -- -- -- --
Groundnut oil 59 14.7 14.7 14.7 3.5 -- --
Soybean oil 123 30.5 30.5 30.5 -- -- --
Sunflower oil 64 15.9 15.9 15.9 -- -- --
Olive oil 97 24.1 24.1 2.2 -- 4.7 --
Canola oil 31 7.7 7.7 0.9 -- -- --
Blended oil 108 26.9 26.9 26.9 -- -- --
Rice bran oil 16 4.0 4.0 2.2 -- -- --
Palmolein oil 7 1.7 1.7 -- 1.7 -- --
Coconut oil 4 1.0 1.0 -- -- -- --
Vanaspati 27 7.2 7.2 3.5 7.2 -- --
Desi ghee 402 100.0 100.0 24.3 24.3 -- 46.7
White Butter 109 27.1 -- -- -- -- 27.1
Yellow Butter 359 89.3 16.9 -- -- 20.2 89.3
Peanut Butter 28 7.0 -- -- -- -- 7.0
Veg. oil based
Sandwich
Spread
88 21.8 -- -- -- -- 21.8
4.I.2.2 Dietary Practices and Meal Pattern
Data were gathered from the subjects regarding food habits, meal pattern
consumption of outside food and dietary intake. This helped in understanding the
type and frequency of food being consumed, in particular high fat foods (fried/
baked) for calculating their nutrient intake. In the present study a two day 24 hour
dietary recall (one working and one non-working day) were conducted to obtain
the dietary intake data of the subjects. In addition, frequency of consumption of
various fried/ baked and dairy food items was assessed using a qualitative food
frequency questionnaire (FFQ). A FFQ helps to give quick and reliable
151
information on the habitual food intake and is often employed as a cross-
validation technique along with 24-hour dietary recalls to enhance quality of the
dietary data.
In the present study the frequency for consumption of fried/ baked and dairy food
items being consumed was categorised as daily, two-three times a week, once a
week, once in 15 days, once a month or occasionally/ very rarely (Annexure V).
Food Habits play an important role in prevention as well as management
of lifestyle diseases. Improper food habits can further contribute towards
development of lifestyle related non communicable diseases (NCD). In the present
study it was noted that most of the subjects surveyed were vegetarians (n=213;
53.0%) while the remaining were either eggitarians (n=92; 22.9%) or non-
vegetarians (n=97; 24.1%). Being an all women study it was expected that larger
number of the study subjects would be vegetarians as in India more number of
women are observed to be vegetarians due to either social or religious reasons in
comparison to men. Epidemiological studies indicate that an appropriately
planned, well balanced vegetarian diet offers several health benefits including a
lower prevalence of lifestyle related diseases in vegetarians as compared to non-
vegetarians. Compared to non-vegetarian diets, vegetarian diets which are low in
saturated fats, cholesterol, high in dietary fibre and contain adequate amounts of
proteins and vitamins can provide several health benefits and offer protective
effects (Deriemaeker et al, 2011). However, as a result of westernisation of the
Indian diets, even the vegetarian diets these days are rich in fat and refined
carbohydrate and low in protein. This rather than having any health benefit/
protective effect could further lead to lifestyle related diseases or aggravate the
condition.
Meal pattern: Nearly half of the subjects (49.5%) were consuming either
three main meals/ day (breakfast, lunch and dinner), while around one-fourth of
them were consuming two (28.9 %; lunch and dinner) main meals and four main
meals (21.6% breakfast, mid-morning, lunch and dinner) per day respectively. The
pattern of consumption of mid-meals/ snacks was also gathered from the subjects
152
and it revealed that nearly 50 per cent of the subjects were having two mid-meals/
snacks per day (early morning tea and evening tea), while 28.4 per cent subjects
were consuming three mid-meals/ snacks (early morning tea, mid-day tea and
evening tea). Others (17.7%) were consuming ≥4 number of mid-meals/ snacks
with a very few (3.5%) consuming 1 mid-meal/ snack in a day (Table 4.I.3). It is
always advised to have three balanced major meals and two or three light mid-
meals/ snacks containing healthy options as it elevates the metabolism and
provides continuous energy to the body, moreover people consuming five to six
meals a day (3 major meals and 2-3 mid-meals/ snacks) feel less hungry and do
not overeat (Misra et al, 2011). However, with large number of mid-meals/
snacks mainly consisting of high fat/ carbohydrate foods coupled with sedentary
lifestyle is leading to increase in the prevalence of obesity and related disorders.
Frequency of eating out: With rapid urbanisation there is hardly any time left for
working mothers to prepare wholesome food for the family on the daily basis. As
a result outside food (fast food/ instant food) has crept into our daily diets leading
to nutrition transition. In an attempt to have a deeper insight on the consumption
pattern, data was gathered on outside food consumption practice. Outside food
was popular among majority of the subjects (99.5%) with only 2 (0.5%) subjects
restricting to only home cooked food. The reasons provided by the subjects for not
indulging in outside food were poor health of spouse and weak digestive system
respectively. Frequency of consuming outside food varied from daily (6.0%) to
once a month (1.0%). Approximately one-fourth of the subjects (25.4%) reported
the consumption of outside food to be thrice a week, while 17.7 per cent reported
the consumption to be once a fortnight with majority of the subjects consuming
the outside food at least once a week (34.3%).
153
Table 4.I.3 Distribution of subjects by their Dietary habits meal pattern and
Frequency of eating out
Particulars N (%) Particulars N (%)
Dietary Habits Consumption of outside
food
Vegetarian 213 (53.1) Yes 400 (99.5)
Eggetarian 92 (22.9) No 2 (0.5)
Non-vegetarian 97 (24.1) Frequency of outside food
consumption
Meal Pattern Daily 24 (6.0)
No. of main
meals/day
3 times a week 102 (25.4)
2 116 (28.9) Twice a week 61 (15.2)
3 199 (49.5) Once a week 138 (34.3)
4 87 (21.6) Once a fortnight 71 (17.7)
No. of snacks/mid
meals/ day
Once a month 4 (1.0)
1 14 (3.5) Type of eating outlet
commonly visited
2 203 (50.5) Restaurants 77 (19.2)
3 114 (28.4) Indian Fast food joint/Halwai 152 (37.8)
≥ 4 71 (17.7) Western fast Food Joint 124 (30.8)
Road side vendor 49 (12.2)
Regular consumption of outside food, which is often high in simple carbohydrates
and fats, in particular trans fats, if prepared in re-used oil or coming through
vanaspati, is one of the prime reasons for the sudden increase in the load of
lifestyle related non communicable diseases in India (Misra et al, 2009a). Among
the eating facilities commonly visited both, Indian fast food joints/ halwai’s and
the western fast food joints were the most favoured ones (28.7% and 28.0%
respectively), but still the nearby roadside vendors were preferred (12.2%) for day
to day eating out/ snacking specifically for gol gappa and papri chaat.
Commonly consumed fried/ baked and dairy foods
Data regarding commonly consumed fried/ baked and dairy food items
were also gathered from the subjects. This data was crucial as it formed
154
the basis for laboratory component of the study in terms of the selection
of fried/ baked and dairy products for laboratory analysis for the fatty
acid profile including trans fatty acids.
Consumption of fried foods (prepared at home and or purchased):
Hectic work schedules, working couples, modernization of the lifestyle
have all contributed towards the concept of “eating out”, which has now
become an important social activity, at both personal as well as
professional level. This has been facilitated by the mushrooming of eating
outlets, in particular fast food joints offering wide range of food items in a
comparatively shorter time. It was found from the data that the subjects
were consuming a wide range of fried foods prepared at home as well as
purchased from the market.
Type of fried foods being consumed: Consumption of fried foods
containing high amounts of fats has been associated with obesity and
related disorders. The data depicted that the subjects were consuming a
wide variety of fried food items which included food items like Potato
Chips (85.3%), Pakora/ Kofta (81.3%), Kachori/ Mathri (86.8%),
Gulabjamun (72.4%), Jalebi/ Imarti (63.2%), Fried Aloo Chaat (84.6%),
Tikki (89.3%), Papri Chaat (74.4%) and Halwa (67.7%). Food items like
Nachos (45.0%), Cutlet (60.2%), Spring Roll (53.0%), Ladoo (51.7%)
were reportedly consumed by comparatively lesser number of subjects,
while more than 90% of them reported consuming foods like, Bread
Pakora (94.8), Vada (98.5%), Dosa/ Cheela (96.0%), Golgappe (99.5%),
Samosa (99.0%), Parantha (99.5%), French Fries (98.5%), Bhujiya
(93.5%), Bhatura/ Poori (91.3%) and Namkeen (99.5%). (Figure 4.I.2).
Frequency of consumption of fried foods: The frequency of
consumption of fried foods by the subjects varied. Food items like bhujiya,
namkeen and parantha were being consumed almost daily by a majority of
them, while ladoo, jalebi and gulabjamun were being consumed only
155
occasionally. Interestingly halwa was being consumed by 32 per cent
subjects on a weekly basis as part of their weekly religious fasts (Tuesday/
Thursday). Golgappe (Paani puri) was one of the most favoured food
items, reportedly being consumed by one-fourth of the subjects once in
every fifteen days, with 46.8 per cent subjects reported to consume it once
a month (Figure 4.I.3). One interesting observation was that food items
like samosa, bread pakora, kachori, gulabjamun etc were a common
feature in the school group parties, any retirement party or on the last
working day of each month.
4.I.2.3 Practices related to frying
Frying is a fast and convenient cooking technique widely used in industrial,
catering and domestic cooking processes. Despite its considerable fat content and
intensified awareness of the relationships between food, nutrition and health,
frying remains a principal cooking method and fried foods are consumed
worldwide with sustainable popularity as a result of their unique and delicious
sensory characteristics (Billek, 2000; Saguy and Dana, 2003).All the subjects
were doing some form of frying at home. The fat/ oil used for frying depended
upon the food item being prepared and the type of frying (shallow/ deep fat
frying) being done. For the purpose of deep fat frying, most of the subjects
(66.4%) were using different types of refined vegetable oils (groundnut; 14.7%,
soybean;30.5%, Sunflower; 15.9%, Olive; 2.2%, canola; 0.9% and rice bran;
2.2%), while around one-fourth of them (26.9%) were using blended refined
vegetable oils. 24.3 per cent subjects reported the use of desi ghee majorly for the
purpose of tempering (baghaar), preparation of parantha, toasting of bread on the
griddle and even for frying of specific foods gulabjamun etc. Surprisingly
vanaspati was also being used by 7.2 per cent of the subjects, basically to replace
desi ghee or for the preparation of mathri/ namakpara/ gulabjamun.
156
Figure 4.I.2: Distribution of subjects by the commonly consumed fried food
items
Quantity of fat used for frying: The total amount of fat/ oil being used
for frying depended on factors like, type and amount of food being fried,
number of servings to be prepared, quantity in each serving etc. For
gathering the information on amount of fat being used for frying,
approximate responses were obtained since measuring the oil prior to
putting it in the frying vessel was not practiced by the subjects. Of the
total 402 subjects enrolled, a little more than half of the subjects (53.7%)
were using approximately 350 - <500 ml of edible fat/ oil for frying at a
time, while 44.5 per cent reported use of 500 - < 750 ml. Interestingly 1.7
per cent subjects reported the use of 750 - < 1000ml of oil for frying,
however, these were the subjects staying in joint of extended families,
with large family size.
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Per
cen
t (%
)
157
Table 4.I.4 Frequency of consumption of commonly consumed fried food
items
Fried Foods Daily
(%)
2-3
times a
week
(%)
Once a
week
(%)
Once in
15 days
(%)
Once
a
Month
(%)
Occasionally/
Very Rarely
(%)
Potato Chips 1.7 5.7 17.7 26.4 32.8 15.7
Bhujiya 44.5 22.9 6.2 3.5 14.2 8.7
Namkeen 35.3 25.6 14.4 10.7 8.5 5.5
Samosa 0.0 1.0 24.1 27.1 29.9 17.9
Bread Pakora 0.0 0.0 2.2 15.7 70.4 11.7
Pakora/ Kofta 0.0 0.0 15.4 43.3 16.7 24.6
Parantha 55.5 3.0 14.7 23.4 2.2 1.2
Bhatura/
Poori 0.0 0.0 11.9 26.4 32.6 29.1
Tikki 0.0 0.0 3.2 24.4 35.3 37.1
Fried Aloo
Chaat 0.0 0.0 1.5 30.3 24.1 44.0
French Fries 0.0 0.7 25.4 46.3 23.1 4.5
Papri Chaat 0.0 0.0 40.8 4.2 26.6 28.4
Gol Gappe 0.0 4.5 15.9 25.6 46.8 7.2
Cutlet 0.0 0.0 3.0 9.7 23.4 63.9
Spring Roll 0.0 0.0 1.0 2.2 20.6 76.1
Vada 0.0 0.5 17.2 29.1 30.8 22.4
Dosa/ Cheela 0.0 4.5 25.9 24.1 17.2 28.4
Nachos 0.0 0.0 0.0 3.2 10.9 85.8
Kachori/
Mathri 0.0 7.2 24.1 30.3 17.9 20.4
Gulabjamun 0.0 0.0 0.7 4.2 27.1 67.9
Jalebi/ Imarti 0.0 0.0 2.2 10.0 24.4 63.4
Ladoo 0.0 0.0 0.0 0.0 4.7 95.3
Halwa 0.0 0.0 32.1 4.2 3.5 60.2
158
Figure 4.1.3: Distribution of the subjects by the frequency of consumption of
fried food items
Duration of heating the fats/ oils before frying: The duration of heating
before frying depends on factors like the type of fried food to be prepared,
quantum of food to be fried, metal of the frying vessel and the heaviness of
the bottom of the frying vessel. Data regarding duration of heating fats/
oils of priorfrying was gathered to have an idea regarding deterioration of
the oil quality before actual frying is initiated. Further it was used for the
laboratory component of the study. Majority of the subjects were not able
to provide exact responses regarding duration of heating the oil prior to
frying thus approximate responses were obtained. Maximum number of
them (57.0%) reportedly allowed the oil to heat for approximately 10-15
minutes before initiating frying, while others reportedly heated the oil for
15-20 minutes prior to frying (Table 4.I.5). A very small percentage of
subjects (2.2%) reportedly heated the oil for as long as 20-30 minutes
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Gulabjamun
Jalebi/ Imarti
Ladoo
Halwa
Spring Roll
Vada
Dosa/ Cheela
Nachos
Kachori/ Mathri
French Fries
Papri Chaat
Gol Gappe
Cutlet
Fried Aloo Chaat
Samosa
Bread Pakora
Pakora/ Kofta
Parantha
Bhatura/ Poori
Tikki
Namkeen
Potato Chips
Bhujiya
Per cent distrbution of subjects
Co
mm
on
ly c
on
sum
ed
frie
d f
oo
d i
tem
s
Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely
159
before initiating frying. This is quite a lot of time and definitely could not
be practiced unless large fat/ oil quantities are used for frying. Further, it
was noted that nearly half of the subjects (50.5%) initiated frying “when
the test food article added to hot fat/ oil quickly rises to the surface”, while
for another 45.3 per cent subjects the correct stage was when the oil started
smoking, however, few subjects (4.2%) reportedly initiated the frying
when the oil started smoking as well as smelling.
Reutilization of oil used for frying was done by a majority of subjects
(95.8%), while the remaining 4.2% either discarded the oil or gave it to
their domestic helps, as they felt that re-heating the oil is harmful for
health and thus should not be practiced. The used oil was mostly re-
utilised for the purpose of re-frying (69.9%) or for preparation of parantha
or vegetable preparation (25.9%). The most common practice of storing
used oil after frying was to allow it to stay in the same karahi in which the
frying was done (53.7%), while 40.3 per cent subjects stored in a separate
vessel, only a very small percentage of subjects (6.0%) were actually
filtering the used oil and storing it separately.
During frying, fats/ oils are subjected to various chemical reactions which
include oxidation, hydrolysis, isomerization, polymerization and
cyclization. As a result, a multitude of products are formed like free fatty
acids, trans fatty acids, mono and diacylglycerols, oxidized monomers,
dimers and polymers. Non-polar dimers and polymers as well as volatile
compounds are also produced (Moreno et al, 2007). At the high
temperatures of frying, thermal reactions occur, giving rise to cyclic
monomers, dimers and polymers. Highly deteriorated oil is referred to as
abused oil. Foods fried in abused fats /oils absorb these products, many of
which are potentially toxic on consumption (Mahungu et al, 1999).
Number of times the fats/ oils are re-used for frying: During frying, a
complex series of various chemical reactions takes place, including
160
thermoxidation, hydrolysis, polymerisation and fission resulting in
increased viscosity, darkening in colour, increased foaming and decrease
in the smoke point of the oil as frying continues. The rate of these
reactions depend on the compositions of the oil, the temperature and length
of frying, whether continuous or intermittent frying is done, the type of
food being fried and whether or not fresh oil is added to replenish the
frying oil (Fennema, 1996). In the present study data regarding re-frying of
the used oil was gathered to get an idea of the deterioration of the oil
occurring at household level. Further re-heating/ re-using the same oil has
been associated with increase in the formation of trans fatty acids.
With the approximate responses obtained from the subjects, the present
study demonstrated that reheating of fats/ oils for the purpose of frying
largely depended on the quantity of fats/ oils left after frying. Nearly one-
fourth of the subjects (27.6%) reportedly did not reheat the fats/ oils
because they either utilise the remaining fats/ oils largely for cooking
purposes (25.9%) or did not use it themselves (1.7%), another one-fourth
(24.4%) of the subjects reportedly reheated the oils once again to be later
used for cooking, while nearly half of them reportedly reused it at least 2-3
times (frying cycles). Further, a small percentage (4.7%) of the subjects
mentioned that they would keep using it till the quantity is reduced to be
used for sautéing vegetables in the same vessel (Table 4.I.5).
Addition of fresh fats/ oils to reheated fats/ oils during frying: Data
indicate that more than half of the subjects (73.4%) were adding fresh fats/
oils to the reheated fats/ oils for frying purpose, while 22.4 per cent did not
replenish the reheated fats/ oils with the fresh fat/ oil (Table 4.I.5). Studies
have indicated that the deterioration of the quality as well as production of
trans fatty acids in used oil lowers down with addition of fresh oil to the
used oil (Romero et al, 2000).
161
Table 4.I.5: Distribution of the subjects by their Cooking/ Frying Practices
Particulars N (%)
Approximate amount of fats/oils used for frying at a time
350 - <500 ml 216 (53.7)
500 - < 750 ml 179 (44.5)
750 - < 1000ml 7 (1.7)
Duration of heating oil before frying
10-15 minutes 229 (57.0)
15-20 minutes 164 (40.8)
20-30 minutes 9 (2.2)
Stage of oil at which frying is initiated
When the test food quickly rises to the oil surface 203 (50.5)
When oil starts smoking 182 (45.3)
When oil starts smoking and smelling 17 (4.2)
Re-utilisation of used oil for cooking purpose
Yes 385 (95.8)
No 17 (4.2)
Re-utilization of oils
Used for frying again 281 (69.9)
Used for sautéing/ preparation of vegetables/ making
parantha’s 104 (25.9)
Throw away or give to their domestic help 17 (4.2)
Storage of Used Oil
Allowed to remain in the same karahi 216 (53.7)
Store in a separate vessel 162 (40.3)
Filtered and stored in separate vessel 24 (6.0)
Number of times the fats/ oils are re-used for frying
Only once 98 (24.4)
2-3 times 174 (43.3)
keep using till the quantity is reduced to be used for sautéing 19 (4.7)
Used for sautéing/ preparation of vegetables/ making
parantha’s 104 (25.9)
Do not re-use 7 (1.7)
Addition of fresh oil to the used oil while frying
Yes 295 (73.4)
No 90 (22.4)
Do not re-use fat/ oil 17 (4.2)
162
Figure 4.I.4 Distribution of subjects by the commonly consumed baked food
items
Consumption of baked foods
Type of bakery products consumed: It was observed that a variety of bakery
products were being consumed by the subjects. Bakery products like bread and
biscuits were reportedly being consumed by all the subjects, however, white
bread (69.1%) was preferred over brown/ wheat bread (30.1%) as some of the
subjects did not like its taste. Cakes and pastry were also being consumed by
all the subjects. A majority of the subjects also reported the consumption of
rusks (78.8%) as their favourite morning tea accompaniment (Figure 4.I.4).
Burger (89.3%), Patties (71.1%), Pizza (78.6%) and cookies/ bakery biscuits
(75.9%) were also reported to be commonly consumed by a large number of
subjects. However, comparatively a smaller percentage of subjects reported
the consumption of bakery products like bun (30.8%), puffs (22.1%), Cream
Wafers (23.1), Muffins/ Brownie (26.6%). High consumption of baked food
replete with fats is also being viewed as a major contributory factor for
obesity, diabetes, heart diseases and related disorders.
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Per c
en
t (%
)
163
Frequency of the consumption of bakery products: Baked food items,
such as rusks and biscuits were reportedly being consumed almost daily by
40 and 32 per cent of the subjects respectively, while food items like cake/
pastry were although being consumed by all, their frequency was reported
to be occasional by most of the subjects (77.6%). However, foods like
pizza were being consumed by nearly one-third of the subjects as part of
weekend eating out (Figure 4.I.5 and Table 4.I.6).
Table 4.I.6 Frequency of the consumption of bakery products
Baked
Food
Daily
(%)
2-3
times a
week
(%)
Once a
week
(%)
Once in
15 days
(%)
Once a
Month
(%)
Occasionally/
Very Rarely
(%)
White
Bread 18.2 10.4 19.7 6.5 15.2 30.1
Brown
Bread 16.4 12.2 1.5 0.0 0.0 69.9
Bun 0.0 3.5 9.0 3.2 5.5 78.9
Biscuits 32.1 26.1 25.4 12.7 3.0 0.7
Patties 0.0 1.0 1.5 9.7 26.9 60.9
Cakes/
Pastry 0.0 0.0 0.0 9.5 12.9 77.6
Puffs 0.0 0.0 1.5 4.7 6.0 87.8
Cookies/
Bakery
Biscuits 0.0 0.0 0.5 3.2 4.7 91.5
Cream
Wafers 0.0 0.0 0.0 0.0 0.0 100.0
Pizza 0.0 0.0 31.8 18.7 17.2 32.3
Burger 0.0 3.0 33.1 25.4 11.9 26.6
Rusk 40.5 4.5 1.5 3.2 23.4 26.9
Muffins/
brownie 0.0 0.0 2.2 1.7 4.7 91.3
Figure 4.I.5 Distribution of the subjects by the frequency of consumption of
baked food items
164
Figure 4.I.5 Distribution of the subjects by the frequency of consumption of
baked food items
Consumption of dairy products and other food items
- Type of dairy products and other food items consumed: The data
gathered depicted that dairy products were consumed by all the subjects in
one form or the other. Milk either full cream milk (48.3%), single toned
milk (28.4%) or double toned milk (23.4%) was being consumed by all the
subjects. Curds and cottage cheese were reportedly consumed by 98.8 per
cent and 100 per cent subjects respectively. Other dairy products being
consumed by the subjects included coffee (73.9%), cream (53.7%), cheese
slice/ spread (52.5%), khoa (25.6%), condensed milk (18.2%) and Rabri
(72.9%). Among the other food items being consumed, around 81.6 per
cent subjects reportedly consumed noodles, while chocolate was
reportedly being consumed by 93 per cent of the subjects. 52 per cent
subjects reported the consumption of vegetarian mayonnaise, while
mayonnaise with egg was being consumed by 23.9 per cent subjects
(Figure 4.I.6). A majority of the subjects also reported the consumption of
packet soups (71.4%).
0% 20% 40% 60% 80% 100%
White Bread
Brown Bread
Bun
Biscuits
Patty
Cakes/ Pastry
Puffs
Cookies/ Bakery Biscuits
Cream Wafers
Pizza
Burger
Rusk
Muffins/ brownieC
om
mo
nly
Co
nsu
med
ba
ked
fo
od
ite
ms
Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely
165
Figure 4.I.6 Distribution of subjects by the commonly consumed dairy/ other
food items
- Frequency of consumption of dairy and other food items: Dairy
products like milk, either full cream/ single/ double toned milk, was being
consumed by most of the subjects on a daily basis, while others consumed
in 2-3 times a week. Tea, was consumed by all the subjects almost twice or
thrice in a day, however, consumption of coffee was reported by only 49.3
per cent subjects and that too either occasionally or very rarely. Curd was
also consumed 2-3 times a week by majority of the subjects, while dairy
products like khoa, rabri, condensed milk and cream were being consumed
only occasionally (Figure 4.I.7).
Among the other food items consumption of chocolates ranged from once
a week (24.1 %) to occasionally (36.3 %), while noodles were reportedly
being consumed once in 15 days by 29.3 per cent of the subjects (Table
4.1.7). Packet soups were also being consumed occasionally by majority of
the subjects (56.5%). A very small percentage of subjects reported daily
consumption of vegetarian mayonnaise (5.5%) and mayonnaise with egg
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Per c
en
t (%
)
166
(1.7%), with majority of them consuming it only occasionally or very
rarely (59.0 and 84.3 % respectively).
Table 4.I.7 Frequency of consumption of commonly consumed dairy and
other food items
Dairy & Other
Food Items
Daily
(%)
2-3
times a
week
(%)
Once
a week
(%)
Once
in 15
days
(%)
Once
a
Month
(%)
Occasionally/
Very Rarely
(%)
Milk Full Cream 20.6 26.4 1.2 0.0 0.0 51.7
Single Toned
Milk 24.4 4.0 0.0 0.0 0.0 71.6
Double Toned
Milk 22.9 0.5 0.0 0.0 0.0 76.6
Curds 14.2 48.0 24.6 11.9 0.0 1.2
Tea 98.5 0.0 0.0 0.0 0.0 1.5
Coffee 4.0 19.2 8.0 11.4 8.2 49.3
Cream 0.0 0.0 4.7 5.5 11.7 78.1
Cottage Cheese 0.0 14.7 41.5 28.4 9.5 6.0
Cheese Slice 3.5 17.2 20.9 4.7 2.7 51.0
Khoa 0.0 0.0 0.0 0.0 0.0 100.0
Condensed Milk 0.0 0.0 0.0 0.0 4.7 95.3
Rabri 0.0 0.0 0.0 0.0 11.7 88.3
Vegetarian
Mayonnaise 5.5 7.0 15.9 4.7 8.0 59.0
Mayonnaise with
Egg 1.7 1.5 3.0 4.2 5.2 84.3
Noodles 0.0 1.0 21.6 29.6 22.9 24.9
Chocolate 0.0 1.7 24.1 16.9 20.6 36.6
Packet soups 0.0 2.7 4.0 16.4 20.4 56.5
167
Figure 4.I.7 Distribution of the subjects by the frequency of consumption of
dairy products and other food items
4.I.3 Knowledge Relating to Trans Fatty Acids
In addition to the knowledge regarding trans fatty acids some preliminary data
were also gathered about their practices relating to re-heating of fats/ oils used for
frying as well as the awareness and practices relating to nutrition labelling (Table
4.I.8). Since the subjects under study were teachers who are aneducated and
cognisant section of the society, it was rather disheartening to know that about
one-third of the subjects (n=129) were aware of the fact that fats/ oils used for
frying should not he re-heated or repeatedly used. Amongst these 14.2 per cent
subjects considered that re-heated fats/ oils could adversely affect our health and
8.2 per cent subjects thought it to be bad for the heart while 9.7 per cent believed
that using repeatedly re-heated fats/ oils could raise the blood cholesterol levels
(Table 4.8).
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Vegetarian Mayonnaise
Mayonnaise with Egg
Noodles
Chocolate
Packet soups
Khoa
Condensed Milk
Rabri
Cream
Cheese Slice
Cottage Cheese
Cofee
Tea
Curds
Double Toned Milk
Single Toned Milk
Milk Full Cream
Per cent distribution of the subjects
Co
mm
on
ly c
on
sum
ed
da
iry
pro
du
cts
an
d o
ther f
oo
d i
tem
s
Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely
168
When the subjects were asked which fat, out of the two, Desi ghee and Vanaspati
is better for our health, 65.4 per cent believed Desi ghee to be the obvious choice
however, surprisingly 4.2 per cent considered vanaspati as a better choice,
thinking that since it is made from vegetable oil it is less harmful. Further, 5.7 per
cent subjects had the view that both are equally good and 24.6 per cent subjects
reported that none of these is a good choice. Further, only 28.1 per cent subjects
had heard of the term trans fats/ Trans fatty acids/ TFA from different sources like
television/ magazine/ newspaper, but only 19.7 per cent could actually describe it
as a “Bad fat” while 5 per cent ended up describing it as a “Good fat”, the
remaining (71.9%) were simply ignorant about it. On being asked whether TFA is
good for health or not, 19.4 per cent answered in negative while remaining 80.6
per cent could not reply.
On being asked regarding the “Nutrition Labels” on the packaged food items, 52.7
per cent subjects reported that they always read the nutrition label before buying
the food product, and 28.4 per cent subjects reported that they checked the label
only “sometimes” while 18.9 per cent said that they did not read the nutrition
label, since they were sure of the quality in the brand or the reputation of the store
from which they were buying the food product. However, among these only 14.6
per cent subjects always remembered to check the TFA content on the “Nutrition
Label” while 11.7 per cent checked it “sometimes” and 73.6 per cent subjects
reported that they did not check the TFA content on the “Nutrition Label”.
The result of this small, yet effective, survey clearly shows the lack of knowledge
regarding trans fats and their adverse effects even among the educated class. Thus
the government as well as health care providers need to take a firm stand
regarding trans fats. Simply mentioning the TFA content on the nutrition label
will not solve the purpose, instead law should be enforced upon the manufacturers
to limit the content of TFA from the food supply and simultaneously consumer
needs to be made aware of the hazards associated with its consumption. We
should take a cue from this survey to plan an initiative to generate awareness
regarding good fats, bad fats and correct ways of using them including
169
disseminating information on healthy cooking practices among general
population.
Table 4.I.8 Knowledge on Re-heating of Fats/ oils and Trans Fats
Particulars N %
Aware of/ Heard of Not Re-heating Fats/ Oils
Yes 129 32.1
No 273 67.9
Aware of the adverse effects of Re-heating Fats/
Oils
It is Bad for health 57 14.2
Bad for heart 33 8.2
It can raise blood cholesterol 39 9.7
Don’t Know 273 67.9
Heard of the term “Trans Fats”/ TFA/ Trans fatty
acids
Yes 113 28.1
No 289 71.9
Knowledge regarding what are “Trans Fats”/ TFA/
Trans fatty acids
Good fat 23 5.7
Bad Fat 79 19.7
Don’t Know 300 74.6
Are TFA good for our health
Yes 0 0
No 78 19.4
Don’t Know 324 80.6
Between Desi Ghee and vanaspati which is a better
fat
Desi ghee 263 65.4
Vanaspati 17 4.2
Both are equally good 23 5.7
None of the two 99 24.6
Do you read “Nutrition Label” provided on the
packaged food item
Yes, always 212 52.7
Sometimes 114 28.4
No/ Do not get the time 76 18.9
Do you check the TFA value given on the “Nutrition
Label”
Yes, always 59 14.6
Sometimes 47 11.7
No/ Do not get the time 296 73.6
170
4.I.4 Preliminary Survey among Cooks/ Chefs
To study the fats/ oils used for food preparation and deep fat frying practices
adopted at commercial level, data has been gathered from 42 different commercial
food establishments randomly selected from Delhi/ NCR through a developed,
designed and pre-tested questionnaire, in order to elicit data on (i) General
information on food items being prepared, (ii) fats/oils being used, (iii)
equipments being used for food preparation, (iv) number of time the used oil is
heated, (v) re-use of fats/ oils and other deep fat frying practices adopted. Further
from each unit one personnel, handling food preparation (1 cook/ chef per unit),
was interviewed to assess their knowledge/ awareness on adverse effects of re-
heating of fats/ oils and trans fatty acids (TFA) on human health and use of
vanaspati.
The preliminary survey had been conducted on 42 food service outlets in various
parts of Delhi and National Capital Region (NCR) covering north (38.1%), south
(26.2%) and central Delhi (16.7%) as well as NCR (Gurgaon-Haryana; 19.0%)
using the pre-designed interview schedule (ANNEXURE VI). The food
establishments surveyed included Restaurants (R; 19.0%), Indian Fast Food
Joints/ Halwais (IFF; 33.3%), Western Fast Food Joints (WFF; 16.7%), Bakery
shops (BS; 14.3%) and Road side vendors (RV; 16.7%) (Table 4.1.9). To maintain
the confidentiality all the outlets surveyed were allotted appropriate codes based
on their type (Table 4.I.11).
Majority of the food service establishment surveyed were serving western foods
(31.0%), while others were serving North Indian/ Mughlai food (21.4%), snacks
(21.4%) or all types of cuisines (19.4%), with only 3 outlets (7.1%) serving South
Indian foods (Table 4.I.10).
171
Table 4.I.9: Type of Food Service Outlets Selected and Different Food Items
being Sold in them
S.No. Food
Service
Outlet
N
(%)
Food items being prepared/ sold
Fried Baked
1 Restaurants
(R)
8
(19.0)
Poories, Bhatura, Spring
roll, Pakoras, Cutlets,
Vada, Samosa
Pastry, Pizza
2 Indian Fast
Food Joints/
Halwais
(IFF)
14
(33.3)
Cutlet, Kebabs, Chicken,
Papri, Gol Gappe, Cutlets,
Vada, Samosa, French
fries, Burger cutlets, Jalebi
Pizza, Patties,
Muffin, Cake
3 Western
Food Joints
(WFF)
7
(16.7)
French fries, Burger,
Cutlets, Onion rings, Fried
vegetables/chicken, Donuts
Pizza, Breads,
Burger buns,
Muffin, Fruit Pie,
Cake, Pastry
4 Bakery
Shops (BS)
6
(14.3)
Spring rolls, Cutlets Pastry, Cake,
Patties, Cookies,
Biscuits, Rusks,
Pie, Tarts,
Muffins, Bread
5 Road Side
Vendors
(RV)
7
(16.7)
Tikki, Fried aloo chaat,
Pakore, Jalebi
- -
Table 4.I.10 : Details of Eating Outlets Surveyed (N=42)
Zone N (%) Type of Cuisine N (%)
North Delhi
16
(38.1)
All cuisines 8 (19.0)
South Delhi
11
(26.2)
North Indian/
Mughlai 9 (21.4)
Central Delhi 7 (16.6) South Indian 3 (7.1)
NCR (Gurgaon) 8 (19.0)
Western
13
(31.0)
Snacks (fried/ baked) 9 (21.4)
172
Table 4.I.11: Type of Fats/ oils used by Food Service Outlets (for frying/
baking/ shortening) S.
No
Establishme
nt/ Codes
Fats/ oils used for Frying Fats/ oils used for
Shortening
Fats/ oils used
for Baking
1 Restaurants
(R)
R1 Vanaspati, Desi ghee,
Groundnut oil
Vanaspati, Groundnut
oil
Margerine,
Butter
R2 Soybean oil Soybean oil, Vanaspati --
R3 Olive oil, Groundnut oil Olive oil, Ghee,
Groundnut oil
Olive oil
R4 Groundnut oil Groundnut oil, Ghee Baker’s
Shortening
R5 Vanaspati Ghee --
R6 Ghee, Groundnut oil Ghee --
R7 Ghee Ghee --
R8 Desi Ghee Desi Ghee --
2 Indian Fast Food Joints/ Halwais (IFF)
IFF1 Olive oil Olive oil --
IFF2 Ghee, Soybean oil Ghee Bakers
Shortening
IFF3 Ghee, Sunflower oil,
Soybean oil
Ghee, Sunflower oil --
IFF4 Vanaspati, Desi Ghee,
Groundnut oil
Desi Ghee --
IFF5 Ghee, Groundnut oil Ghee, Groundnut oil Baker’s
Shortening
IFF6 Ghee, Desi Ghee, Soybean
oil
Ghee, Soybean oil --
IFF7 Vanaspati, Desi Ghee,
Groundnut oil
Vanaspati, Desi Ghee --
IFF8 Desi Ghee, Soybean oil Desi Ghee, Soybean oil --
IFF9 Vanaspati Vanaspati, Refined
vegetable oil
Margerine
IFF10 Vanaspati, Desi Ghee Vanaspati Baker’s
Shortening
IFF11 Ghee Ghee --
IFF12 Vanaspati Vanaspati --
IFF13 Ghee Ghee --
IFF14 Desi Ghee Desi Ghee Butter
3 Western Fast Food Joints (WFF)
WFF1 Palm Oil -- Butter, Baker’s
Shortening
WFF2 Palm Oil, Soybean oil -- Butter
WFF3 Olive oil, Groundnut oil -- Margerine
WFF4 Palm oil -- Butter
WFF5 Soybean oil -- Butter
WFF6 Palm oil, Soybean oil -- Palm oil,
Margarine
WFF7 Palm oil -- Palm oil,
Butter
4 Bakery
Shops (BS)
BS1 -- -- Butter,
Margarine
173
BS2 -- -- Baker’s
Shortening
BS3 Groundnut oil -- Margarine
BS4 Soybean oil -- Butter,
Margerine
BS5 -- -- Baker’s
Shortening
BS6 -- -- Baker’s
Shortening
5 Road Side Vendors (RSV)
RV1 Vanaspati, Refined
vegetable oil
Vanaspati, Refined
vegetable oil
--
RV2 Ghee Ghee --
RV3 Refined vegetable oil -- --
RV4 Refined vegetable oil Refined vegetable oil --
RV5 Vanaspati, Refined
vegetable oil
Vanaspati, Refined
vegetable oil
--
RV6 Refined vegetable oil Refined vegetable oil --
RV7 Ghee Ghee --
Depending on the type of food establishment a variety of food items were being
prepared and sold. It was noted that these food establishments used different fats/
oils for food preparation particularly for frying and baking. The type of fat being
used by the surveyed food establishments is given in Table 4.I.11
- Data pertaining to the Cooks/ Chefs: For the purpose of this study a total
of 42 chefs/ cooks of different food service establishment were surveyed,
which included 35 cooks/ chefs and 7 road side vendors.
- Age/ Educational status of the Cooks/ Chefs: The mean age of the chefs/
cooks under study was 33.8 years. From the data obtained, it was observed
that out of the total chefs/ cooks surveyed; only 2 were below 20 years of
age, while a majority of them (42.9%) were between the age range of 20 -
30 yrs, with an equal number (n=9; 21.4%) were in the age group on 30-
40 and 40- 50 years. However, 9.5 per cent were above the age of 50
years. (Table 4.I.12).
174
Table 4.I.12 Age/ Educational status of the Chefs/ Cooks
Parameters (N=42) Chefs/ Cooks
N (%)
Age group (years)
< 20 2 (4.8)
20 – < 30 18 (42.9)
30 – < 40 9 (21.4)
40 – < 50 9 (21.4)
50 – < 60 4 (9.5)
Education Status
Illiterate 5 (11.9)
Primary Education 10 (23.8)
Secondary Education 12 (28.6)
Senior-secondary 5 (11.9)
Graduate 10 (23.8)
It was found that the level of literacy was quite high in the chefs/ cooks surveyed
(n=37; 88.1%), with 23.8 per cent respondents educated till graduation, however,
these were chefs/ cooks working either in multinational food chain outlets or in
specialty restaurants requiring good culinary and communication skills. Majority
of the chefs/ cooks had completed their secondary level education (28.6%), while
23.8 per cent had studied till primary and 11.9 per cent up to senior secondary
level. However, there was still a considerable size of respondents who were
illiterate (n=5; 11.9%), these were either the cooks working at small restaurants/
establishments, road side vendors or workers cooking with them (Table 4.I.12).
Deep Fat Frying Practices
- Fats/ Oils used for Frying, Shortening and Baking: It was noted that
most of the eating joints reportedly used vanaspati (21.4%), either alone or
in a blend with other fats/ oils for frying (Figure 4.I.8) Other fats/ oils
which were reportedly being used predominantly included Groundnut oil
and Soybean oil (21.4% each), Palm oil (11.9%), Olive Oil and Sunflower
oil (2.4% each) and Refined vegetable oil (7.1%) respectively. Desi ghee
was also reportedly being used for frying purpose (19.0%) in combination
with other fats/ oils. Interestingly, some eating outlets (n=10; 23.8%)
175
reported the use of “Ghee” without specifying the type (Desi Ghee or
Vanaspati).
- A large majority of the surveyed outlets reportedly used “Ghee” (31.0%)
for shortening. While others were using either vanaspati (19.0%) or desi
ghee (11.9%). Some reported the use of either used (left after frying) or
fresh Soybean oil (7.1%), Groundnut oil (9.5%), Palm oil (11.9%) and
refined vegetable oil (RVO; 11.9%). One outlet was reportedly using Olive
oil for shortening. The data revealed that for the purpose of baking, most
of the cooks/ chefs reportedly used either butter (21.4%) or baker’s
shortening (19.0%). Margarine was used by 16.7 per cent cooks/ chefs,
while a very few reported the use of palm oil (4.8%), and olive oil (2.4%).
It is to be noted that both vanaspati and margarine are partially
hydrogenated fats and are loaded with trans fatty acids. However, the
information on fats/ oils being used could not be obtained from 11.9 per
cent of the outlets where baking and frying was commonly being
employed.
- The equipment used for frying depended upon the type of food item being
prepared. Shallow fat frying is usually done on a griddle (tawa) while deep
fat frying can be done using karahi or electric fryer. Karahi is generally
used in the preparation of bigger items e.g. pakora/ jalebi/ samosa/ mathri/
kachori/ vada etc. while electric fryer is used in the preparation of smaller
items like French fries, spring rolls/ smileys etc. Moreover use of karahi is
more often seen in traditional establishments while the electric fryer is
used by establishments serving western foods. In the present study it was
observed that a majority of the outlets were using a combination of
equipment’s depending upon the nature of food item being fried (Table
4.I.13).
- Majority of the eating outlets were using a combination of karahi, electric
fryer and griddle (n= 9; 21.4%), others were using combination of
176
karahiand griddle (n=6; 14.3%), karahi and electric fryer (n=2; 4.8%)
followed by electric fryer and griddle (n=1; 2.4%). All the Western fast
food joints and other outlets where predominantly western foods were
prepared, used only electric fryers (19%), while remaining were using
karahi (16.7%) and griddle (11.9 %) Electrical fryers have an advantage
over karahi, since the temperature in electrical fryer can be controlled due
to presence of thermostat. This ensures that the temperature of oil being
heated does not go very high there by causing less degradation.
Figure 4.I.8 Distribution of eating outlets by the type of fat/ oil used for the
purpose of frying, shortening and baking (Multiple responses)
Table 4.I.13: Equipment used for Frying of Food Items
Equipment Used N (%)
Karahi 7 (16.7)
Electrical fryer 8 (19.0)
Griddle 5 (11.9)
Karahi, Electric fryer, griddle 9 (21.4)
Karahi, Electric fryer 2 (4.8)
Karahi, Griddle 6 (14.3)
Electric Fryer, Griddle 1 (2.4)
Not Applicable 4 (9.5)
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
21.4 19.0
23.8
21.4 21.4
7.1
2.4 2.4
11.9
19.0
11.9
31.0
9.5
7.1
11.9
2.4 2.4
11.9
2.4 4.8
16.7
21.4
19.0
Percen
t (%
)
Fats/ oils used for frying Fats/ oils used for shortening Fats/ oils used for baking
177
- Duration of heating the fats/ oils before frying: The duration of heating
fat/ oil before frying depends on the amount of fat/ oil being used for
frying, the type of food item being prepared and the metal of the frying
vessel. In the current study, most of the cooks/ chefs were not able to give
a definite answer when they were asked regarding duration of heating the
fats/ oils before frying, therefore approximate responses were obtained
(Figure 4.I.9). The study revealed that nearly one-fourth of the
outlets(26%) reportedly heated fat/ oil for 30 to < 45 minutes prior to
frying, while 17 per cent reportedly heated the oil for < 30 minutes and an
equal number of the respondents (n=7) reportedly heated the fat/ oil for 45
to < 60 minutes before frying. Interestingly a whopping 31 per cent
reportedly heated the fat/ oil for approximately 1 hour or more before
frying. Since, these were only the reported responses; the actual duration
of heating may differ.
Figure 4.I.9 Distribution of eating outlets based on the duration of heating
fat/ oil before frying
- Total Duration of Usage of Fat/ oils: The quality of frying medium is
dependent on its duration of usage. In the outlets surveyed the total
duration of use of fat/ oil for frying varied between 5-18 hours with an
average of 10.6 ± 2.4 hours depending on the type of eating outlet and the
demand of fried foods (Table. 4.I.14). A fair number of commercial outlets
(n=7; 16.7 %) reported that they continued heating karahi/ fryer (1 lot of
oil) for nearly 6 - <8 hours, while about 14.3 per cent of them (n=6)
17%
26%
17%
31%
9%
< 30 minutes 30 - < 45 minutes 45 - < 60 minutes ≥ 60 minutes Do not fry
178
continued heating the same lot of oil for nearly 8- <10 hours. Reported
duration of heating fat/ oil was as high as ≥16 hours at 5 eating outlets. An
equal number of outlets (n=4; 9.5%) reportedly heated/ used the oil for
continuously 12- <14 hours and 14- <16 hours respectively.
- Number of times the fats/ oils are reheated for frying: Reheating refers
to heating of fat/ oil again once the heated fat has been taken off from the
heat source or the heat source has been removed and reportedly leads to
greater degradation in the oil quality. The number of times fats/ oils is
reheated plays an important role in determining its quality. In the present
study, the approximate responses obtained from the cooks/ chefs revealed
that re-heating largely depended on the amount of fat/ oil left after frying
and the number of frying cycles it has completed.
Table 4.I.14: Duration of Use of fat/ oils at different eating outlets
Duration of Use of Oil N % Outlets
<6 hours 2 4.8 BS5, BS6
6 - <8 hours 7 16.7 R5, R6, IFF1, IFF3, IFF7, IFF11, IFF14
8 - <10 hours 6 14.3 R2, R7, IFF10, RV1, RV3, RV6
10- < 12 hours 3 7.1 R3, R4, IFF6
12- <14 hours 4 9.5 R1, IFF4, IFF5, RV2
14- < 16hours 4 9.5 IFF2, IFF9, IFF12, RV4
≥ 16 hours 5 11.9 IFF13, IFF8, RV5, RV7, R8
No response/ Information
refused 7 16.7
WFF1, WFF2, WFF3, WFF4, WFF5, WFF6,
WFF7
Not Applicable 4 9.5 BS1, BS2, BS3, BS4
- However, majority of the respondents (31.0%) reportedly reheated the fats/
oils approximately 5-9 times (frying cycles), while 24 per cent cooks/
chefsreheated them for 10-14 times and 14% reheated fats/ oils 15-19
times. This could lead to great deterioration in the fat/ oil. (Figure 4.I.10).
179
31%
24%
14%
21%
10%
5 - 9 times
10 - 14 times
15 - 19 times
20 - 24 times
Do not fry
It was reported that the frying medium being used for more than 12 hours
would undergo cooling overnight before being reused the following
morning. Even during working hours, many cooks discontinued heating
when there was no demand for fried foods. Intermittent heating and
cooling is more destructive than continuous heating since the production of
peroxides and their highly undesirable decomposition products is repeated
with each cycle of heating and cooling (Clark and Serbia, 1991).
Figure 4.I.10 Distribution of eating outlets by the number of times fats/ oils
were re-heated
In most of the food outlets under study (n= 18; 42.9%) the re-used oil was stored
in canisters/ some other vessels after manual filtering (35.7%) so as to remove the
left over food particles, however, in 38 per cent outlets it was still being stored
without any straining and was allowed to remain in the same karahi in which
frying was done. It is well documented that straining helps in reducing the
degradation (oxidation and formation of free radicals) of oils, however,
information on this was not provided by 7 (16.7%) outlets. Additionally, at several
180
outlets (38%) the frying vessels were left uncovered exposing the oil to
atmospheric oxygen. It has been reported that problems in quality of oil occur in
batch frying operations in restaurants and fast food joints, where frying is
necessarily discontinuous and often carried out by unskilled personnel (Berger,
2005).
The criteria for judging deterioration of the oil was rather subjective and included
visible changes like darkening or thickening of oil and accumulation of deposits.
In the present study the data on reported criteria for determining deterioration of
oil indicates that “change in colour of the oil” was the main criteria indicating oil
deterioration (45.2%), whereas in some outlets (11.9%) turning of oil specifically
into shades of black was considered as a sign of deteriorated oil, this was the
general criteria followed by most of the road side vendors. Interestingly few
eating outlets (7.1%) were using the number of frying cycles as the set point after
which either the oil was replenished or discarded, while some others (14.3%) were
using a combination of number of frying cycles and change in the colour of oil as
deterioration mark”, however, they did not reveal the number of frying cycles
after which the oil was discarded. There was one outlet (RV5) where bad smell of
oil was taken as the sign of oil deterioration (Table 4.I.15). This shows that most
of the food service outlets are still not serious regarding the quality of oil for
frying food items and have adopted a rather casual approach towards this issue.
Utilization of re-heated fats/ oils: Frying fat/ oil as a heat and mass transfer
medium has an important effect on foods fried in it. It can affect the quality of
foods in terms of trans fatty acid content, shelf life, nutrition and eating quality
(Blumenthal, 1991). Utilizing the re-heated fat/ oil can further deteriorate the
quality of fat/ oil. In the present study it was observed that majority of the cooks/
chefs utilized the re-used fat/ oil either for the purpose of cooking (sautéing/ as
shortening) and frying (35.7%) or for cooking alone (31.0%). Interestingly, 7.1
per cent cooks/ chefs reported that the used oil was further sold to road side
vendors; such exploitation is a matter of serious concern because it would lead to
further deterioration of the used fat/ oil and hense the quality of food.
181
Table 4.I.15 Cooking/ Frying Practices Adopted at the Eating Outlets under
Study (N=42)
Details of Eating Outlets Selected
Container used for storing
used oil N (%) Criteria for determining
deterioration of oil N (%)
Canister/ Any other storage
vessel 18 (42.9)
Change in colour of the
oil 19 (45.2)
Retained in Karahi 13 (31.0) Oil turns black 5 (11.9)
No response/ Information
refused 7 (16.7) Oil starts smelling bad 1 (2.4)
Not Applicable 4 (9.5) Follow a fixed number of
heating cycles 3 (7.1)
Storage condition for used oil
Stored after straining 15 (35.7)
Change in colour and
number of frying cycles
(both)
6 (14.3)
Stored without any straining 16 (38.0) No response/ Information
refused 4 (9.5) No response/ Information
refused 7 (16.7)
Not Applicable 4 (9.5) Not Applicable 4 (9.5)
It is important to note that re-heating/ re-frying of oil induces production
of elaidic acid (trans isomer) in the fat/ oil, which is a cause for serious
concern. Moreno et al, 1999 reported that intensive heating of fats/ oils
caused an increase in the amount of trans fatty acids. A very small
percentage of respondents reportedly discarded the degraded oil (Table
4.I.16). However, information could not be obtained on this from 5 cooks/
chefs.
Knowledge, Attitudes and Practices regarding fats and oils: In addition
an attempt was made to assess knowledge of the cooks/ chefs regarding the
adverse effects of re-heating of fats/ oils and trans fatty acids from the
health perspective. Only 7 chefs/ cooks were aware of the adverse effects
of re-heating fats/ oils and reported that prolonged heating was harmful but
182
were unable to assign any reason while 73.8 per cent had not even heard of
not reheating fats/ oils (Table 4.I.17). Regarding consumption of
vanaspati, 57.1 per cent considered it to have a positive impact on health,
whereas only 14.3 per cent considered it to have a negative impact.
Table 4.I.16 Utilization of re-heated fats/ oils
Utilization of re-heated fats/ oils N %
Cooking 13 31.0
Cooking and Frying 15 35.7
Sold to Road Side vendors 3 7.1
Discard the oil 2 4.8
Could not get information 5 11.9
Do not fry 4 9.5
- Reasons for using vanaspati/ hydrogenated fat: Hydrogenated oils
(vanaspati) are commonly being used in India and other countries as a
cooking medium and in various traditional products (Mahungu et al 1999).
From the data attained, it was inferred that the cooks/ chefshad different
reasons for using vanaspati. 45.2 per cent considered vanaspati to be a
cheaper substitute for ghee and 21.4 per cent considered that it adds taste
to the food. According to 16.6 per cent cooks/ chefs, foods prepared in
vanaspati can be stored for a longer time than the ones prepared using any
other oil, interestingly an equal per cent (16.6%) of cooks/ chefs working
with multinational food chain outlets did not consider it as a good choice
of fats/ oils (Table 4.I.17).
183
Table 4.I.17 Knowledge and Awareness among cooks/ chefs regarding re-
heated fats/ oils, vanaspati and trans fatty acids
Knowledge and Awareness among cooks/ chefs
regarding re-heated fats/ oils, vanaspati and trans fatty
acids
n %
Heard of Not Re-heating Fats/ Oils
Yes 7 16.7
No/ Don’t Know 31 73.8
Do Not Fry 4 9.5
Aware of adverse effects of Re-heating Fats/ oils
Yes 7 16.7
Don’t Know/ Not Aware 35 83.3
Is Vanaspati Good for Health
Yes 24 57.1
No 6 14.3
Don’t Know 12 28.6
Reasons for using Vanaspati
It is a cheaper substitute for Desi Ghee 19 45.2
Adds Taste to the Food 9 21.4
Food prepared using vanaspati can be stored for long 7 16.6
Not a good choice 7 16.6
Aware of/ heard of the term "Trans Fats"/ "Trans Fatty
Acids"/ TFA
Yes 7 16.6
No/ Don’t Know 35 83.3
Aware of Adverse effects of Trans fats
Aware 5 11.9
Partially Aware 2 4.8
Not Aware 35 83.3
- Knowledge on Trans fatty Acid: Small data were also gathered from
cooks/ chefs of food outlets regarding their present knowledge on Trans
fats (Table 4.I.17) On being asked about Trans fats approximately 16.6 per
cent were aware of or had heard the term Trans fats, but only 11.9 per cent
actually knew what it is. Most of the workers (83.3%) had absolutely no
knowledge of either trans fats or their adverse effects on human health.
Those who had some knowledge were mostly the personnel employed at
multi-national food chains following some standard specifications.
184
The present preliminary survey is an eye opener in highlighting the quality of fat
being used and the deep fat frying practices adopted at commercial
establishments. A previous study by Goyal and Sundararaj (2009) had also
indicated similar findings and this issue is a cause of serious concern.
4. II LABORATORY ANALYSIS
The laboratory analysis has the following components:
Estimation of TFA content of various fats/ oils at room temperature
Studying the formation of TFA in fats/ oils subjected to varying
temperatures with or without frying the food items
Estimation of TFA content in select food items (fried/ baked/ dairy food
items)
After obtaining necessary permissions, the work was carried out at Foods
Laboratory of Institute of Home Economics Hauz Khas, New Delhi (heating/ re-
heating and frying of fats/ oils) and at the Department of Chemical Engineering,
Indian Institute of Technology, (IIT) New Delhi (for analysis of the fatty acid
profile including the TFA content of the fats/ oils and the food items).
4.II.1 FATTY ACID PROFILE OF EDIBLE FATS/ OILS
On the basis of the preferences marked by the subjects in the preliminary survey, a
total of 17 fats/ oils were selected for laboratory analysis of their fatty acid profile
including TFA content. For each fat/ oil two most preferred brands were selected
and used for analysis, however, for Canola oil, Rice bran oil, refined palmolein oil
and peanut butter only one brand sample could be obtained, while for Desi ghee
and Vanaspati four samples of each were taken for analysis. For blended refined
vegetable oil a total of three samples were obtained. Apart from this, samples of
Coconut oil (cold pressed)* and coconut oil (hard pressed)* were provided by the
Department of Science and Technology (DST) while a sample of Red palm oil**
was obtained from the Institute of Home Economics (IHE) which were also
185
analysed for fatty acid profile including trans fatty acids. Therefore, in all a total
of 33 fats/ oils samples were identified for laboratory analysis. Each fat/ oil was
appropriately coded and where available, the date of manufacturing, date of
expiry, batch number, cost per unit, nutritional information, ingredients and health
claims (if any) were noted for each fat/ oil (Table 4.II.1).
Different fats/ oils used for analysis include:
Yellow Butter: Amul, Britannia
White Butter: Gopala, Local Dairy
Peanut Butter: Fun Foods
Desi Ghee: Madhusudan, Fresh and Pure Cow Ghee, Cow Ghee Gopala,
Milk food
Vanaspati: Dalda, Rath, Panghat, Gagan
Sandwich Spread: Amul Lite Bread Spread
Mustard Oil: Dhara Kachhi Ghani, Panghat
Groundnut Oil: Fortune Goldnut, Dhara
Soybean Oil: Nature Fresh Acti Lite Soybean Oil, Fortune
Sunflower Oil: Nature Fresh Acti Lite Sunflower Oil, Sundrop
Olive Oil: Leonardo (Pomace), Bertulli (Classico)
Canola Oil: Hudson
Rice Bran oil: Ricela
Refined Palmolein oil: Raag
Blended Refined Vegetable Oil: Saffola Gold, Sundrop Heart, Saffola
Tasty
Coconut Oil (Hot Pressed and cold pressed)
Red palm Oil
*DST is keen in finding out the superiority of cold pressed coconut oil over the
hot pressed oil in terms of fatty acid profile including TFA content; if any.
**While Red Palm Oil was analysed as it is being considered as semi-solid fat
to replace the partially hydrogenated vegetable oils for use in bakery
products.
The packaged oil samples purchased from the various markets were kept in
refrigerator (4-6ºC) till those were used for analysis. The brand names and
nutritional information are given in Table 4.II.1 and Annexure (IX).
186
Prior to conducting the detailed fatty acid profile, the procedure for assessment of
fatty acid profile was standardised. For this, a total of 3 known edible fat/ oil
samples were used (Table 4.II.2). As given in methodology, these oils were
converted to their FAMEs and were made to run in GC along with the fatty acid
standards, following which preliminary calculations were done for identification
of various components present in oils to find their compositions.
The amount of saturated (SFA), cis-monounsaturated fatty acid (MUFA), cis-
polyunsaturated fatty acid (PUFA) and Trans fatty acids (TFA) was calculated for
each sample. The amount of SFA, cis-MUFA, cis-PUFA and TFA in the analyzed
samples has been reported as gram/ 100 gram of fat/ oil. To ensure accuracy,
duplicate sample of each fat/ oil were analyzed. In olive oil-F, the estimated
percentage of SFA, cis-MUFA, and cis-PUFA was found to be 36.2, 59.9 and 3.1
respectively. The results of this sample indicate that the SFA content was higher
than the appropriate range specified in codex standard. However, in Olive oil-P,
the SFA, cis-MUFA, cis-PUFA percentage was within the normal range as per the
codex standard. Trans fatty acid was detected in only olive oil-F (TFA; 0.35%). In
both the samples of olive oil, oleic acid was the predominant fatty acids detected.
Higher oleic acid (42-63%) and lower linoleic acid (23-37%) has been reported to
provide the best flavour and stability to the oil (Warner et al, 1997). In case of the
mustard oil sample, the percentage for SFA, cis-MUFA, and cis-PUFA was found
within the range as per the codex standard wherein, about 55% of total fats
comprised of MUFA; and its TFA content was negligible (0.05%). Erucic acid
was the predominant unsaturated fatty acid. In North India, mustard oil is one of
the commonly used cooking oils. Study by Rastogi et al, (2004) has indicated that
use of mustard oil compared to sunflower oil as frying medium, lowers the risk of
ischemic heart disease.
187
Table 4.II.1 Brand Names and Nutrition Related Information of the Fats/ Oils Samples Selected for Analysis
S.No Type
Selected
Brands Code Note Composition Nutritional Information (g/100g of fats/ oils)
Mark/
Certification
Fats of Animal Origin
1 Yellow
pateurised
butter
Amul YBA Best Before 9
Months from
Manufacture
Butter, Common salt
Energy: 722 Kcal, Energy from fat: 720, Total Fat: 80g, SFA:
51g, Cholesterol: 80mg,Sodium:836 mg, CHO: 0g, Protein:
0.5g, Vitamin A: 65 mcg.
--
2 Yellow
pateurised
butter
Britannia YBB Best Before 9
Months from
Manufacture
Milk Solids, Iodized
Salt. Milk Fat: 80%
Minimum
Energy:724Kcal, Protein: 0.4g, Carbohydrate: 0.5g, Fat: 80g,
Sodium:1048 mg, Phosphorous: 15mg, Vitamin A: 650 mcg
--
3 White
Butter
Gopala WBG Best Before 9
Months from
Manufacture
-- -- --
4 White
Butter
Haryana
Dairy WBHD Best Before 9
Months from
Manufacture
-- --
5 Desi Ghee Madusuda
n DGM Best Before 9
Months from
Manufacture
-- Energy: 897 Kcal, Protein: NIL, Carbohydrates: NIL, Total Fat:
99.7g, Sugar: NIL, Fiber: NIL, SFA: 58g, MUFA: 28g, TFA:
5g, PUFA: 2 g, Cholesterol: 211-216mg, Vit A: 2000-3500IU
--
6 Desi Ghee
(cow)
Gopala DGCG Best Before 9
Months from
Manufacture
-- -- --
7 Desi Ghee
(cow)
Fresh &
Pure; Pure
Cow Ghee
DGCFP Best Before 9
Months from
Manufacture
Cow milk fat Energy: 897 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:99.7grams, SFA:63.0g, MUFA: 24.5g, PUFA: 1.7g, TFA:
3.0g, Cholesterol: 0.4g, Vitamin A: (mcg) 700, Sodium(mg):0,
Phosphorous (mg):0, Calcium: 0 , Sugar:0g
--
8 Desi Ghee Milk food DGMF Best Before 12
Months from
Manufacture
Pure ghee Energy: 808 Kcal, Protein: NIL, Carbohydrates: NIL, Total Fat:
89.5g, Sugar: NIL, Fiber: NIL, SFA: 52.5g, MUFA: 22.4g,
TFA: 3.5g, PUFA: 3.2 g, Cholesterol: 0.19g, Vit A: 2000-
3500IU
AGMARK
(ghee special
grade) E-5
188
Fats/ oils of Plant Origin Code Note Composition Nutritional Information (g/100g of fats/ oils)
Mark/
Certification
9 Peanut
Butter
Fun Foods PBFF Best Before 9
Months from
Manufacture
Roasted peanuts,
Sugar,
Hydrogenated
Edible Vegetable
oil, Edible common
salt
VALUE per 16 gram: Calories: 100, CHO: 3.5g, Dietary fiber:
1g, Sugar:1.5g, Protein:4g, Total Fat: 8g, SFA: 1.5g, TFA: 0g,
Cholesterol:0mg, Sodium: 80 mg, Iron: 1%
--
10 Sandwich
spread
(vegetable
fat)
Amul Lite
Bread
Spread
PHVFA
L
Best Before 9
Months from
Manufacture
Refined Vegetable
Oils, Milk Fat,
Common Salt,
Skimmed Milk
Powder, Emulsifiers
(E#@@), Stabilizers
(E471), Class II
Preservatives (E
202), Acidity
Regulator (E330) &
Antioxidant (E 319).
Total Fat: 70%,
Milk Fat: 10%
Energy: 634 Kcal, Energy from fat: 630 kcal, Total
Fats:70grams, SFA:35g, Cholesterol: 2.4g, Total CHO: 1 gram,
Added Sugar: 0g, Sodium: 650 mg, Added Vitamin A, mcg 900,
Added Vitamin D, mcg: 5. Not a significant source of dietray
fiber and iron. Vitamin A not less than 30 IU per g and Vitamin
D not les than 2 IU per g.
--
11 Mustard oil Panghat ROMP Best Before 9
Months from
Manufacture
Mustard Oil Energy: 900 Kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100g. --
12 Mustard oil Dhara
Kachi
Ghani
ROMD
KG
Best Before 9
Months from
Manufacture
Mustard Oil Energy: 900 Kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100g. --
13
Groundnut
oil
Fortune
Goldnut
ROGF
Best Before 9
Months from
Manufacture
refined groundnut
oil, permitted
antioxidant (E-319)
Energy: 900Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100grams, Cholesterol: 0mg, Vitamin A, 750 mcg (2500
I.U.) and Vitamin D, 5 mcg (200 I.U.) per 100 gwhen packed
and sold in Gujrat. Free from argemone oil.Vitamin E: 50 mg,
Oryzanol: 1000 mg. Free from Argemone Oil
--
189
14
Groundnut
oil
Dhara
ROGD
Best Before 8
Months from
Manufacture
Groundnut Oil,
Vitamin A & D
Energy: 900kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100gm,
Added vitamin A: 2500 I.U./750 ml, Added Vitamin D: 200
I.U./5 mcg
15
Soybean oil
oil
Fortune
ROSB
Best Before 9
Months from
Manufacture
Refined soybean oil,
Permitted
antioxidant (E-319).
Contains Vitamin A,
750 mcg (2500
I.U.)Vitamin D: 5
mcg (200 I.U.) Free
from Argemone oil
Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100grams, SFA:14g, MUFA: 18g, PUFA: 68g, Omega 3:
6g, other PUFA: 62g, TFA: 0g, Cholesterol: 0g, Added Vitamin
A: 750mcg/2500 I.U., Vitamin D: 5 mcg/ 200 I.U.
--
16
Soybean
Oil
Nature
Fresh
Acti-Lite
Refined
Soybean
Oil
ROSBN
F
Best Before 9
Months from
Manufacture
Soybean oil,
Vitamin E 2273
mcg/100g oil,
Vitamin A 750mcg/
100g oil, Vitamin D
5 mcg/100g oil,
Dimethyl
Polysiloxame (900a)
5 ppm
Energy: 884 Kcal, Protein: 0 Gram, CHO: 0 gram, Total Fats:
100grams, SFA: 104.4g, MUFA: 23.3g, PUFA: 57.9g, TFA:
<0.5g, Cholesterol: 0g, Added Vitamin A 2500 I.I./750 mcg,
Added Vitamin D: 200 I.U./ 5 mcg, Vitamin E: 2273 I.U./ 2273
mcg. Free from Argemone Oil
This oil is
added with
DMPS
(**Diemethyl
Polysiloxane)
as a result the
food fried in
such oil
absorbs lesser
oil; verified
by 2 well
known
laboratories.
17
Sunflower
Nature
Fresh Acti
Lite
Sunflower
Oil
ROSFN
F
Best Before 9
Months from
Manufacture
Sunflower oil, Vit A
750 mcg /100 g oil,
Vit. E 273mcg/
100g oil, Vitamin D
5 mcg/100 g Oil,
Dimethyl
Polysiloxane (900a)-
5 ppm
Energy: 884 Kcal, Protein: 0 Gram, CHO: 0 gram, Total Fats:
100grams, SFA:10.3g, MUFA: 19.5g, PUFA: 65.7g, TFA: <
1g, Cholesterol: 0g, Added Vitamin A 750 mcg, Added
Vitamin D 5 mcg, Vitamin E: 273 mcg. Free from Argemone
Oil
Added with
DMPS, thus
the food fried
in such oil
absorbs lesser
oil; verified
by 2 well
known
laboratories
190
18
Sunflower
Sundrop
ROSF
Best Before 9
Months from
Manufacture
Refined edible
sunflower oil, Vitamin
A, Vitamin D2,
Antioxidant (TBHQ),
anti foaming agent
(Dimethyl
Polysiloxane (DMPS].
Free from Argemone
oil
Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100grams, SFA:9g, MUFA: 25g, PUFA: 66g, TFA:
0g, Cholesterol: 0g, Added Vitamin A: 801mcg/2670 I.U.,
Vitamin E: 50 mcg/50 I.U.
--
19 Ricebran
oil
Ricela RORB
R
Best Before 9
Months from
Manufacture
No mention of
ingridients. Free from
argemone oil,
Contains permitted
anti-oxidants & Anti-
foaming agent
Energy: 900Kcal, Protein: 0 Gram, CHO: 0 gram, Sugar:
0g, Total Fats:100grams, SFA:24g, MUFA: 42g, PUFA:
34g,TFA: 0g, Cholesterol: 0mg, Vitamin E: 50 mg,
Oryzanol: 1000 mg. Free from Argemone Oil
--
20
Olive
Bertulli-
Classico
ROOB
C
Best before 24
months from
manufacture
Olive Oil- Composed
of Refined & Virgin
olive oils.
Energy: 820 kcal, Protein: 0g, CHO: 0g, Total fat: 91g,
SFA: 15g, MUFA: 66 g, PUFA: 10 g, TFA: 0.27g,
Vitamin E: 12 mg, Sodium: 0mg
This product may
become cloudy at
around 45º F. Store
Tightly capped in a
cool dry place
21 Olive Leonard
o,
Pomace
ROOL
P
Oct-12 Refined olive pomace
oil and extra virgin
olive oil (oil
comprising
exclusively olive oils
that have undergone
refining and oils
obtained directly from
olives
Serving size: 1 Tbsp=14g, Servings per container:66,
Values per serving: Energy: 120 kcal, Protein:0g, CHO:0g,
Total fat:14g, MUFA: 10g, PUFA:2g, SFA:2g, TFA:0g,
Cholesterol:0mg, Sodium:: 0mg.
--
191
22 Canola Hudson ROC Best Before 9
Months from
Manufacture
Canola oil, Imported
Refined canola oil
Serving size: 2tsp (10g), serving per container: 88, calories
80, Calories from fat 80, Total fat 9g, Saturated fat: 0.5g,
MUFA: 6g, PUFA: 2.6g, Omega-6: 1.7g, Omega-3: 0.8g,
Trans fat: 0g, Cholesterol: 0g, Sodium: 0g, Sodium: 0g,
Total Carbohydrate: 0g, Dietary fiber: 0g, Sugar: 0g,
Protein: 0g, Protein: 0g, Vitamin E: 1.6mg. Nutritional
Information for 100 g: Total fat 92g, Saturated fat: 7g,
MUFA: 54g, PUFA: 26g, Omega-6: 17g, Omega-3: 9g,
Trans fat: 1g, Cholesterol: 0g, Sodium: 0g, Sodium: 0g,
Vitamin E: 16mg.
--
23 Palmolein Raag
Gold
ROPR Best before 6
months from
packaging when
stored in a dry
place away from
heat & Light
Refined Palmolein
Contains Added
vitamin A, 750 mcg
(2500 I.U) and
Vitamin D, 5mcg (200
I.U.)
Energy: 900kcal, Fat: 100g, SFA: 48g, MUFA: 41g,
PUFA: 11g, TFA:0g, Cholesterol 0mg
--
24 Blended oil Saffola
Gold
RBOS
G
Best Before 9
Months from
Manufacture
Refined Rice Bran Oil
and Refined Safflower
(Kardi) Seed Oil.
Contains Permitted
Antioxidants
[319,330] & Anti
Foaming Agent
[900a]. Free from
Argemone Oil.
Nutrient information per 10 g (serving size); Energy: 90
Kcal, Protein: 0g, Carbohydrate:0g, Total Fat:10 g,
Saturated Fatty Acid: 2.0g, Monounsaturated Fatty Acid:
3.6g, Poly unsaturated Fatty Acid: 4.3g, TFA:0g,
Oryzanol:400mg, Cholesterol 0mg
--
25 Blended oil Sundrop
Heart
RBOS
H
Best Before 9
Months from
Manufacture
Refined Rice Bran Oil
80%, Refined
Sunflower Oil 20%.
Contains TBHQ. Free
from Argemone Oil
Energy: 900 kcal, Proteins: 0g, Carbohydrate:0g, Total
fatty acids: 100g, SFA: 21g, MUFA:46g, PUFA: 33g,
TFA:0g, Cholesterol: 0g, Vitamin E (mg/I.U. **) 50/50,
Oryzanol (mg):500
--
192
26 Blended Saffol
a tasty
RBOS
T
Best before 6
months from
packaging when
stored in a dry
place away from
heat & Light
Refined corn oil (80%
by wt) and refined
safflower seed oil (20%
b wt), contains
permitted anioxidants
(319,330), and anti
foaming agent (900a).
Free from argemone oil
per 10g: Energy:90kcal, Protein:0g, Carbohydrate:0g,
Total fat:10g, Saturated fatty acid: 1.2g, monounsaturated
fatty acid: 2.7g, Poly-unsaturated fatty acid: 6.1g, Trans
fats: 0g, cholesterol omg
AGMARK (Refined
Blend-A)
27 Vanaspati Pangh
at
PHVO
VP
Best Before 9
Months from
Manufacture
palm oil, Sesame oil,
Vitamin A, Vitamin D
Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100 grams, Added Vitamin A: (mcg/IU) 750/2500,
Added Vitamin D: 5/200 (mcg/IU)
--
28 Vanaspati Rath PHVO
VR
Best Before 9
Months from
Manufacture
palm oil, Sesame oil,
Vitamin A, Vitamin D.
Hydrogenated
vegetable fats used -
contains trans fats
Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100 grams, SFA: 47-53, MUFA:44-48, PUFA: 4-7,
Trans fat: 8-20g, Added Vitamin A: (mcg/IU) 750/2500,
Added Vitamin D: 5/200 (mcg/IU)
--
29 Vanaspati Dalda PHVO
VD
Best Before 9
Months from
Manufacture
Palm oil, Palmolein,
Sesame oil, Vitamin A
& Vitamin D.
Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total
Fats:100 grams, Cholesterol: 0mg, , Vitamin A: (mcg)
750, Vitamin D: 5 (mcg)
30 Vanaspati Gagan PHVO
VG
Best Before 9
Months from
Manufacture
Palm oil, Rice brans oil,
cotton seed oil, soybean
oil, sesame oil
Energy:900 Kcal, Protein: NIL, Carbohydrates: NIL,
Total Fat: 100g, Vit A: 750mcg (25 IU), Vitamin D2:
5mcg (2 IU)
--
31 Coconut Oil
(Hot Pressed)
COHP -- -- -- --
32 Coconut Oil
(Cold Pressed)
COCP -- -- -- --
33 Red Palm Oil RPO -- -- -- --
CHO: Carbohydrates
193
Table 4.II.2 Fatty Acid Profile of Edible oils Used for Standardization
Type Percentage (g/100g oil)
SFA cis-
MUFA
cis-
PUFA
cis- Total
Unsaturated
fatty acid
TFA cis-
ώ 3
cis-
ώ 6
cis-
ώ 9
Predominate
fatty Acid
Olive oil
Standard
composition
8-
17.1
55-
84.6
3.5-
22.5
- - - - - -
Olive oil-F 36.2 59.9 3.1 63.4 0.35 - 2.9 57.4 Oleic Acid
Olive oil-P 16.6 70.2 11.7 81.9 - 0.24 9.06 70.1 Oleic Acid
Mustard Oil
Standard
composition
1.2-
12.0
35.5-
89.0
16 -
44
Mustard oil 12.4 55.5 30.2 85.7 0.05 10.1 14.8 14.41 Erucic Acid
After standardising the protocol (by analyzing two samples of olive oil and one
sample of mustard oil along with the fatty acid standards) and taking all due
precautions, the fats/ oils samples were analysed for their complete fatty acid profile
including TFA. Each oil sample was analyzed in duplicate to ensure the accuracy of
the results. In total, estimation of fatty acid profile including TFA content has been
carried out for 33 fat/ oil samples.The amount of SFA, cis-MUFA, cis-PUFA and
TFA in these samples have been reported as g/ 100g of fat/ oil (Table 4.II.3 and
4.II.4). Fatty acid profile of the selected samples of fats/ oils indicated that there were
individual differences between the fatty acid composition of oil samples of different
brands of the same oil, such as two brands of mustard oil had variations in their fatty
acid profile. TFA being a major risk factor for heart diseases, insulin resistance,
diabetes and several other health problems (Mozaffarian et al, 2006), occupies the
major focus of the present study.
194
Figure 4.II.1: Fatty Acid Profile of Selected Samples of Fats/ Oils
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
g/
10
0g
SFA cis-TUFA Total TFA
195
4.II.1.1 Fatty Acid Profile of Select Fat/ Oil Samples of Animal Origin
Laboratory analysis of the fatty acid profile of fat/ oil sample of animal origin was
carried out for a total of eight samples (Table 4.II.3 and Figure 4.II.2). The fat
samples of animal origin (yellow butter: YBA and YBB; white butter: WBC and
WBHD; Desi ghee: DGM, DGCFP, DGCG and DGMF) were predominantly high in
saturated fatty acid content (YBA; 65.2%, YBB; 60.6%, WBC; 56.3%, WBHD;
61.5%, DGM; 42.2%, DGCFP; 43.1%, DGCG; 41.3% and DGMF; 55.7%). The fats/
oils with the highest SFA levels were yellow butter (YBA; 65%) and white butter
(WBHD; 61.5%). These animal fats had significantly high levels of cis-MUFA as
compared to cis-PUFA. These samples had oleic and palmitic acid as the predominant
fatty acid. Plamitic acids are solid at room temperature and stable during storage and
frying. Although palmitic acid rich oils show high stability during storage and frying,
however, they are associated with increased LDL cholesterol and have shown to
elevate the risk for heart diseases. Omega 3 fatty acid, though in small amounts was
present in all these samples except for one sample of Desi ghee (DGMF), the levels
were highest in white butter (WBHD; 3.04%) and lowest in yellow butter (YBA;
0.85%). Omega 6 fatty acid was present in all the samples of animal fats ranging from
as low as 0.62 per cent (YBA) to as high as 11.1 per cent (DGM).
Trans fatty acid was also present in all the fat samples of animal origin, however,
there was a wide variation in their TFA content (ranging between 0.68%; White
butter- WBHD to 8.6%; Desi Ghee-DGCG). Results indicate a significant amount of
trans fatty acid in three samples of desi ghee (DGCG; 8.68%, DGMF; 2.2%, DGCFP;
1.72%), while a comparatively lower level in one sample of (DGM; 0.68). The
surprising revelation was presence of higher TFA (8.6%) in Desi Ghee (DGCG)
reported to be prepared from cow’s milk. The TFA content of Desi ghee has been
reported to be 2 % of the total fat in the Indian literature (Ghafoorunissa and
Krishnaswamy, 1994), however, in the present study it ranged between 0.68g to as
high as 8.6g The probable reason for this could be animal’s feed, which can be a
significant cause for high TFA levels in ruminant products.
196
Table 4.II.3: Laboratory Analysis of Fatty acids profile; of Fat Samples Animal
Origin Selected for the Study
Oil
Type
Code Brand Fatty Acid Profile (g/ 100g of fat) Predomi
nant
Fatty
Acid SFA cis-
MUF
A
cis-
PUF
A
cis-
ώ 3
cis-
ώ 6
cis-
ώ 9
cis -
Total
unsatur
ated
fatty
acid
TF
A
Yellow
Butter
YBA Amul
Lite
65.2 31.5 1.4 0.85 0.62 29 32.9 1.8 OA +PA
Yellow
Butter
YBB Britannia 60.6 32.6 3 1.5 1.5 30.3 35.6 1.1 OA +PA
White
Butter
WBC Gopala 56.3 37.6 4.2 2.9 1.3 28.7 41.8 1.6 OA +PA
White
Butter
WBH
D
Haryana
Dairy
61.5 26.3 10.4 3.04 3.06 22.4 36.8 1.09 OA +PA
Desi
ghee
DGM Madhusu
dan
42.2 38.2 13.8 2.4 11.1 34.3 52.1 0.68 OA +PA
Desi
ghee
DGC
FP
Fresh &
Pure;
Pure
Cow
Ghee
43.1 42.1 12.9 2.9 9.2 29.7 55.07 1.7 OA +PA
Desi
ghee
DGC
G
Gopala 41.3 36.6 11.4 1.08 10.3 25.4 48.06 8.6 OA +PA
Desi
ghee
DGM
F
Milk
Food
55.7 34.6 7.1 - 7.1 25.4 41.7 2.2 OA +PA
OA= Oleic Acid, PA= Palmitic Acid, EA= Erucic Acid, LA= Linoleic Acid
197
Figure 4.II.2: Fatty Acid Profile of Selected Samples of Fats of Animal Origin
4.II.1.2 Fatty Acid Profile of Fat/ Oil Samples of Plant Origin
Liberalization and globalization has led to increased availability of many varieties of
edible oils in India. The consumption of vegetable oils has increased by almost
threefolds in developing countries like India. In the present study a wide variety of
fat/ oil samples of plant origin were selected which included fats like peanut butter,
sandwich spread, vegetable oils (mustard, groundnut, soybean, sunflower, rice bran,
olive and canola), blended refined vegetable oils and partially hydrogenated vegetable
oils (PHVO)/ Vanaspati (Table 4.II.4 and Figure 4.II.3)
Erucic acid was the predominant fatty acids found in both the samples of mustard oil
(ROM and ROMDKG), however, these contained low levels of SFA (17.8% and
16.86% respectively) and high levels of cis-MUFA (ROM; 57.08 g/100g and
ROMDKG; 45.8 g/100g) as well as cis- PUFA (ROM; 23.6g/100g and ROMDKG;
31.3g/100g). The TFA content of these samples showed indicated variations, with one
sample (ROMDKG) containing as high as 4.6 per cent of TFA (the highest among the
refined vegetable oils; and barring partially hydrogenated vegetable oils/ vanaspati),
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
Yellow
Butter-A
Yellow
Butter-B
White
Butter-C
White
Butter-D
Desi
ghee-M
Desi
ghee-CFP
Desi
ghee-CG
Desi
ghee-MF
g/
10
0g
SFA cis-MUFA cis-PUFA Total TFA
198
which also had highest level of omega 3 fatty acid (10.3%) and a fair amount of
omega 9 fatty acid (43.07%), while the other sample (ROM) containing 0.95 per cent
per cent of TFA and 18.2% of omega 9 fatty acid.
There were slight individual variations in the fatty acid profile of both the samples of
groundnut oil. Both were low in SFA (ROGF; 30.04% and ROGD; 23.9%), high in
cis-MUFA (ROGF; 42.3% and ROGD; 53.8%) and had average levels of cis-PUFA
(ROGF; 25.03% and ROGD; 21.5%). However, the cis-omega 9 fatty acid was higher
in ROGD (53.8%) as compared to ROGF (34.1%). ROGD also contained small
amounts of trans fatty acid (0.68%) which was absent in ROGF. The predominant
fatty acid found in both these oils was oleic acid.
Both the samples of soybean oil showed approximately similar fatty acid profile;
these had low levels of SFA (ROSB; 17.9%, ROSBNF; 18.05%), average cis-MUFA
(ROSB; 23.8%, ROSBNF; 26.1%), high cis-PUFA (ROSB; 58.2%, ROSBNF; 53.9%)
and omega-9 fatty acid content (ROSB; 23.8%, ROSBNF; 24.3%). While ROSB was
high in cis-omega 3 fatty acid (14.9%), ROSBNF showed higher level of cis-omega 6
fatty acid (38.4%). Trans fatty acid content of ROSBNF was 1.78 per cent which was
absent in ROSB. Linoleic was the predominant fatty acid in both the soybean oil
samples; although essential, it is unstable during storage and frying.
Similar to the soybean oil, both the samples of sunflower oil were high in cis-PUFA
(ROSF; 56.5% and ROSFNF; 54.5%) low in SFA (ROSF; 9.5% and ROSFNF;
12.8%) and had linoleic acid as the predominant fatty acid. Both the samples were
high in cis-omega 6 fatty acid (ROSF; 55.8% and ROSFNF; 53.5%) had average
levels of cis-MUFA (ROSF; 31.1% and ROSFNF; 29.6%) and had significant
amounts of trans fatty acid content (ROSF; 2.7% and ROSFNF; 3.0%).
Oleic acid was the predominant fatty acid present in Olive oil (ROOL, ROOBC) and
Canola Oil (ROC). While Rice bran oil (RORBR) and one sample of refined
blended oil (RBOSH) contained both oleic acid and linoleic acid as the predominant
fatty acids. Oleic acid is liquid at room temperature and relatively more stable during
storage and frying however, it is well known from the literature that oils rich in oleic
acid are more prone to produce undesirable flavour during repeated frying. Further
high percentage of cis-MUFA was found in both the samples of olive oil (ROOL;
199
83.7% and ROOBC; 73.7%), one sample of refined blended oil (RBOSG; 87.08%) as
well as in refined rice bran oil (RBOR; 69.3%). All these samples had low levels of
cis-PUFA (ROOL; 1.77%, ROOBC; 3.5%, RORBR; 12.6% and RBOSG; 5.2%). In
one sample of refined blended oil (RBOSH) cis-PUFA constituted around 78 per cent
of total fatty acids, which was the highest level among all the fats/ oil samples of
animal/ plant origin under study. The trans fatty acid content was undetectable in both
the samples of olive oil and two samples of refined blended oil (RBOST and
RBOSH), however, canola oil, rice bran oil and one sample of refined blended oil
contained around 1.7 per cent, 0.35 per cent and 0.5 per cent TFA respectively.
Nearly 50-60 years back, majority of the households in northern India were using only
desi ghee and mustard oil as the cooking medium. Slowly hydrogenated fats (in the
form of vanaspati) came into the picture. Vanaspati entered India in 1960s as a solid
cooking fat that was promoted as vegetable ghee and within some time it was a
common cooking medium in almost every household. It was being used for the
purpose of cooking, frying and shortening. It was only recently that the health effects
of hydrogenated fats came into lime light and the TFA related health effects surfaced.
In the present study all the samples of partially hydrogenated vegetable oils
(vanaspati; PHVOVG, PHVOVR, PHVOVP, PHVOVD) had almost similar fatty
acid profile. These had high levels of SFA (PHVOVG; 47.08%, PHVOVR; 49.1%,
PHVOVP; 41.9%, PHVOVD; 41.05%), low levels of cis-PUFA (PHVOVG; 5.9%,
PHVOVR; 9.8%, PHVOVP; 7.9%, PHVOVD; 5.2%) and fairly good amount of cis-
MUFA ranging from 27.2 per cent (PHVOVR) to 36.6 per cent (PHVOVP). These
partially hydrogenated vegetable oil samples were predominantly high in oleic acid
and palmitic acid. High levels of trans fatty acids were detected in all the samples of
partially hydrogenated vegetable oils (PHVOVG; 14.6%, PHVOVR; 12.9%,
PHVOVP; 13.3% and PHVOVD; 13.9%).
The TFA content of vanaspati in the Indian literature reports a level of as high as 53
per cent (Ghafoorunissa and Krishnaswamy, 1994). While, the analysis of fatty acid
composition in the NIN laboratory of currently available brands/ batches of vanaspati
sold in market (n=24) across the country showed wide variation in total TFA content,
elaidic acid was reported to be the major trans isomer. The numbers of brands/batches
200
having different range of TFA were reported to be: 11 brands/ batches with 5 - 15%
TFA, 5 brands/ batches with >15-20% TFA and 8 brands/ batches with >20 - 38 %
TFA of total fatty acids. The lower TFA level in some brands/ batches may be due to
use of higher proportion of palm oil or its fractions in the mixture of oils used for
hydrogenation (Ghafoorunissa, 2008).
Amongst all the categories of fats/ oils under study, partially hydrogenated vegetable
oils (vanaspati) had the highest amount of trans fatty acids. It is a matter of serious
concern since partially hydrogenated vegetable oils are being used rather liberally
even in the big urban cities, posing a serious threat to human health.
The coconut oil samples, both cold pressed and hot pressed had 99.6 and 95 per cent
of SFA respectively with undetectable amount of trans fatty acid. However, the cis-
MUFA and cis-PUFA levels estimated for both these samples were below the normal
range specified in codex standard. Coconut oil is the highest natural source of lauric
acid.
Compared to the Red palm oil (SFA; 54.8%, cis-PUFA; 3.4% and cis-MUFA;
40.9%), Refined Palmolein oil (RPOR) had a slightly higher level of SFA (56.5%)
and cis-PUFA (8.7%) and lower levels of cis-MUFA (35.3%) as (RPO) sample. No
TFA could be detected in refined palmolein oil; however, it was present in Red Palm
oil (0.68%). The predominant fatty acids in both these oils were palmitic and oleic
acid. Oleic acid alone constituted around 40.9 per cent and 35.3 per cent of total fat in
red palm oil and refined palmolein oil respectively. Both these oils (RPO and RPOR)
are being viewed as possible replacement for TFA rich fats/ oils. However, according
to Kritchevsky, (2000) red plam oil is considered as the nutritionists’ oil as it is rich in
β-carotene, tocopherols and tocotrienols, which are not only the vitamins or their
precursors but potent natural antioxidants, which also accord greater stability to the
oil.
It has been recommended that from stability point of view frying oils should contain
high amounts of oleic acid (50-65%), fair amounts of linoleic acid (20-30%) and
decreased amounts of α-linolenic acid (not more than 3%).
One sample each of peanut butter (PBFF) and vegetable oil based sandwich spread
(PHVFA) were also analysed for their fatty acid profile including TFA. Both these fat
201
spreads are reportedly considered as healthy fats and are now being preferred by the
elite class over yellow and white butter. The laboratory analysis revealed that Peanut
butter was high in SFA (52.7%) similar to one sample of white butter (WBC; 56.3%),
however, it had higher levels of cis-MUFA (43.1%) and was free of trans fatty acids.
On the other hand the sandwich spread (PHVFA) although low in SFA (25.4%);
similar to one of the samples of groundnut oil and high in cis-MUFA as well as cis-
PUFA (36.8% and 34.1%) had rather high levels of trans fatty acid (4.4%). Thus,
peanut butter and the yellow/ white butter’s turned out to be the preferred fat that can
be used as sandwich spread rather than vegetable oil based sandwich spread.
Owing to the deleterious effects of trans fatty acids on human health, they are the
prime focus of the present study. The study revealed that apart from partially
hydrogenated vegetable oils (vanaspati), which had very high levels of TFA (range;
12.9% to 14.6%), small amounts (range; 0.35% - 4.6%) were also detected in some
refined oils and vegetable fats ranging between 0.35 per cent to 4.6 per cent (ROM;
0.95%, ROMDKG; 4.6%, ROSF; 2.7%, ROSFNF; 3%, ROSBNF; 1.78%, ROGD;
0.68%, ROC; 1.6%, RORBR; 0.35%, RBOST; 0.5%, RPO; 0.68%, PHVFA; 4.4%),
which otherwise are claimed to be free of trans fats (Figure 4.II.4). This may be due to
the formation of TFA during the refining (deodorization) stage. Thus proving the
hypothesis that even refined oils (not all) may in reality not always be trans fat free.
There is paucity of data in Indian literature regarding TFA content of fats/ oils.
However, some data has been reported by Centre for Science and Environment
(Annexure XII), showing variability in the fatty acid profile including TFA content
within each category of fat/ oil (CSE, 2009).
202
Table 4.II.4 Laboratory Analysis of the Fatty acids profile of Fat Samples (of
Plant Origin) Selected for Analysis
OA= oleic Acid, PA= Palmitic Acid, EA= Erucic Acid, LA= Llinoleic Acid
Fats/ Oils Code Brand Fatty Acid Profile (g/ 100g of fat/ oil) Predominant
Fatty Acid SFA cis-
MUFA
cis-
PUFA
cis-
ώ 3
cis-ώ
6
cis-ώ
9
cis -Total
unsaturated
fatty acid
TFA
Peanut
Butter
PBFF Fun
Foods
52.7 43.1 4.01 - 4 43.1 47.2 0 OA+PA
Sandwich
Spread
PHVFA Amul
Lite
24.5 36.8 34.1 - 34.4 36.8 71 4.4 -
Mustard
Oil
ROM Panghat 17.8 57.08 23.6 5.9 17.6 18.2 80.7 0.95 EA
Mustard
Oil
ROMDKG Dhara
Kacchi
Ghani
16.8 45.8 31.3 10.3 13.5 43.07 77.1 4.6 EA
Groundnut
Oil
ROGF Fortune
Goldnut
30.04 42.3 25.03 - 15.5 34.1 67.4 0 OA
Groundnut
Oil
ROGD Dhara 23.9 53.8 21.5 0.46 21.08 53.8 75.3 0.68 OA
Soybean
Oil
ROSB Fortune 17.9 23.8 58.2 14.9 24.7 23.8 82.08 0 LA
Soybean
Oil
ROSBNF Nature
Fresh
18.05 26.1 53.9 8.3 38.8 24.3 80.1 1.78 LA
Sunflower
Oil
ROSF Sundrop 9.5 31.1 56.5 0.7 55.8 31.1 87.6 2.7 LA
Sunflower
Oil
ROSFNF Nature
Fresh
12.8 29.6 54.5 0.9 53.5 29.6 84.1 3 LA
Rice Bran
Oil
RORBR Ricela 16.3 69.3 12.6 1.01 11.6 69.3 82.01 0.35 OA+LA
Olive Oil ROOBC Bertulli
Classico
22.6 73.7 3.5 0.6 2.9 73.7 77.3 0 OA
Olive Oil ROOL Leonardo
Pomace
14.4 83.7 1.77 - 1.7 83.7 85.5 0 OA
Olive Oil ROOF Figaro 36.2 59.9 3.1 - 2.9 57.4 63.4 0.35 OA
Canola Oil ROC Hudson 9.7 57.2 31.3 9.4 21.9 57.2 88.6 1.6 OA
Palmolein
Oil
ROPR Raag 56.5 35.3 8.7 - 8.7 35.3 44 0 OA+PA
Refined
Blended
Oil
RBOSH Saffola
Gold
3.02 18.9 78.04 - 78.04 18.9 96.9 0 LA+OA
Refined
Blended
Oil
RBOSG Sundrop
Heart
7.6 87.08 5.2 - 5.2 87.08 92.3 0 OA
Refined
Blended
Oil
RBOST Saffola
Tasty
45.9 18.7 35.3 - 35.3 18.7 54.07 0.5 OA+LA
Vanaspati PHVOVG Gagan 47.08 32.2 5.9 2.6 3.3 32.2 38.2 14.6 OA+PA
Vanaspati PHVOVP Panghat 41.9 36.6 7.9 0.92 7.02 31.4 44.6 13.3 OA+PA
Vanaspati PHVOVR Rath 49.1 27.2 9.8 5.7 4.02 26.4 37.09 12.9 OA+PA
Vanaspati PHVOVD Dalda 41.05 35.7 5.2 1.5 3.6 19.01 40.9 13.9 OA+PA
Coconut
Oil
COHP Hot
Pressed
95.02 1.6 0.28 - 0.28 1.2 1.9 0 Lauric Acid
Coconut
Oil
COCP Cold
Pressed
99.6 0.28 0 - - 0.28 0.28 0 Lauric Acid
Red Palm
Oil
RPO -- 54.8 40.9 3.4 - 3.4 40.9 44.3 0.68 OA+PA
203
Figure 4.II.3 Fatty Acid Profile of Selected Samples of Fats/ Oils of Plant Origin
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
g/
10
0g
SFA cis-MUFA cis-PUFA Total TFA
204
Figure 4.II.4 Laboratory Analyzed values of the Trans Fatty Acid Content in Selected Samples of Fats/ oil
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00g
/ 1
00
g
205
4.II.2 TFA CONTENT OF HEATED/ RE-HEATED FATS/ OILS
Deep fat frying is a worldwide popular method of food preparation because it is quick
and not very expensive method of cooking which produces desirable fried food
flavour, pleasant colour appeal (golden brown colour) and crisp texture needed in
most of the preparations. However, during the high temperature used in frying lipids
undergo a variety of chemical and physical changes occur due to thermal
decomposition (Stevenson et al, 1984).During deep frying, the fat is continuously
exposed to elevated temperatures in the presence of air. This causes the change in
sensory and nutritional quality of the fat and ultimately a point is reached where it is
no longer possible to prepare high quality fried foods and the frying fat needs to be
discarded. Frying, is also being considered as a contributory factor leading to TFA
formation, which otherwise are thought to be a product of partial hydrogenation. The
formation of TFA during food frying is closely related to the temperature and the oil
use time (Moreno et al. 1999). Considering the negative effects of trans fatty acids on
health, analysis of the nutritional value of fats/ oils used for frying should be made
mandatory.
Several researches have been carried out in the western countries to study the effect of
formation of TFA during frying indicate an increase in the concentrations of trans
isomers with increase in temperature and duration of heating. As a result several
European countries have formed stringent rules and have recommended that the
frying oil temperature must not exceed 180ºC. However, in India due to paucity of
knowledge and data, there are no such guidelines or checks on the temperature of oil.
The food manufacturers/ cooks as per their convenience continue to heat/ re-heat the
fats and oils in large karahi/ fryers at varying temperature and many times rather high
temperature for long hours with intermittent episodes of cooling (as per the demand
for fried foods). All this results in TFA formation heating and re-heating with
intermittent episodes of cooling down which is even more harmful for the human
health. Thus, in view of frying being a common method of food preparation in our
country, an India specific study is very much required to understand the effect of
formation of TFA when oil is constantly heated at high, varying temperatures with
intermittent episodes of cooling. Therefore this part of the present study was designed
to assess the formation of trans fatty acids in edible fats/ oils during heating/ frying,
206
with intermittent cooling and then re-heating wherein experiments were performed in
the laboratory using six different types of fats/ oils. 500 ml of these fats/ oil samples
were heated to 180ºC, maintained at this temperature of 30 minutes before the test
food item (50 g or pre-frozen French fries) were fried in it. Thereafter the same oil
sample was heated further to 220ºC and again maintained at this temperature for 30
minutes and then the test food sample (50 g or pre-frozen French fries) were fried to
golden brown colour. The karahi was then removed from the hot plate and the oil was
allowed to cool for one hour and brought down to room temperature (RT; 30-35ºC).
After this one hour period of cooling the oil was re-heated to 180ºC again and
maintained for 30 minutes, and like the previous exercise the test food was fried; the
oil was further re-heated to 220C and similar procedure of frying was repeated in the
same way. Thus, each fat/ oil sample was subjected to four continued frying in heated/
re-heated fat/ oil samples. For comparison, the fats and oil samples were heated/ re-
heated under similar conditions without frying the test food and this served as their
control counterparts. The fats/ oils selected for heating/ re-heating included:
Soybean oil
Groundnut oil
Olive oil
Canola oil
Desi Ghee
Vanaspati
Using Gas chromatography coupled with flame ionization detector (AOAC Official
Method 996.06) the selected fat/ oil samples were then analyzed for their fatty acid
profile including trans fatty acid content, both before and after subjecting them to
heating/ re-heating at 180ºC and 220ºC, with or without frying the test food item. As
indicated in methodology, prior to initiating the frying cycles with the selected fat/ oil
samples, the entire procedure of heating/ re-heating was standardised with respect to
the quantity of oil, temperature ranges, durations of heating, and the test food to be
fried using Blended vegetable oil-refined (BVO-R). Thereafter these standardized
conditions were employed for the rest of fat/ oil samples. Due to their standard
composition/ measurement and easy availability, pre-frozen French fries (PFFF;
purchased from a local supermarket) were selected as the test food for frying.
207
Initially, the oil samples were subjected to 3 different temperatures i.e. 180ºC, 220ºC
and 240ºC both, with and without frying the food item. However, after the initial
experimentation for the final protocol, only two temperature ranges (180ºC and
220ºC) were shortlisted for heating/ re-frying and frying in heated/ re-heated fats and
oils. These temperature ranges and durations were selected on the basis of studies
carried out by Bansal et al (2009), Martin et al (2007) and the practices reported by
the subjects as per the survey.
Heating Protocol: For each fat/ oil sample, a karahi containing 500ml of the fat/ oil
sample was taken and placed on the hot plate. The temperature sensors were
immersed in fat/ oil taking due caution that the temperature sensor did not touch the
base of the karahi (to avoid any error) and the temperature was set at 180ºC. Once
the temperature reached the set point, it was maintained at 180ºC for 30 minutes and
the first 30 ml of fat/ oil sample was drawn, cooled and stored in a cool box for
analysis. Thereafter, the same fat/ oil sample was heated till 220ºC, maintained at this
temperature for 30 minutes and subsequently 2nd
batch of 30 ml of fat/ oil sample was
drawn. Thereafter the karahi containing fat/ oil was taken off the hot plate and the
fat/ oil was allowed to cool for a period of 60 minutes.
In order to study the effect of re-heating on formation of TFA, the same fat/ oil, was
re-heated (after the cool down period of 60 minutes), and the entire process
(heatingat 180ºC and 220ºC) was repeated again. For each of the selected fat/ oil
sample, a total of 4 fat/ oil samples were drawn (Heating at 180ºC, Heating at 220ºC
cooling down for one hour, re-heating the same oil again at 180ºC and finally re-
heating at 220ºC) over a duration of approximately 7 hours.
Frying Protocol:Similar to the heating protocol, frying protocol was followed
wherein, for each fat/ oil sample, a karahi containing 500ml of the fat/ oil sample was
taken and placed on the hot plate. The temperature sensors were immersed in fat/ oil
taking all due pre-caution the temperature was set at 180ºC. Once the temperature
reached the set point, it was maintained at 180ºC for 30 minutes, thereafter first
frying cycle was carried out. During each frying cycle, 50 gram of food i.e. pre-frozen
French fries (PFFF) were fried. At the end of frying cycle 30 ml of oil was drawn,
cooled and stored in a cool box for analysis. Thereafter the same fat/ oil sample was
heated till 220ºC, maintained at this temperature for 30 minutes and subsequent
frying cycle was performed. Thereafter the karahi containing fat/ oil was taken off the
hot plate and the fat/ oil was allowed to cool for a period of 60 minutes.
In order to study the effect of re-heating on formation of TFA, the same fat/ oil, was
re-heated (after the cool down period of 60 minutes), and the entire process (frying at
180ºC and 220ºC) was repeated again. For each of the selected fat/ oil sample, a
total of 4 frying cycles were carried out (Frying at 180ºC, Frying at 220ºC cooling
down for one hour, frying in the same re-used oil again at 180ºC and finally frying at
220ºC) over a duration of approximately 7 hours.
208
4.II.2.1 Fatty Acid Profile including TFA of the frozen French Fries
prior to frying
Prior to initiating the frying protocol, the fatty acid profile including TFA of the pre-
fried French fries was analyzed using gas chromatography method coupled with flame
ionization detectors.
Table 4.II.5: Brand Name and Nutrition Related Information of the Frozen
French fries
Brand Batch/
Lot No.
Date of
manufacture
Ingredients/
Composition
Nutritional Information
Mc-Cain B 17:03 2-Feb-2011 Potatoes, Edible
vegetable oil
per 100 g: Energy: 196
kcal, Protein:3g, CHO:
37g, Sugar:0g, Total fat:4g,
SFA: 2g, MUFA:1g,
PUFA:1g, TFA:0g,
Cholesterol:0mg
For the assessment of fatty acid profile including the TFA content in the pre-fried
French fries, the sample of the pre-fried French fries was homogenized/ ground and
an accurately weighed representative portion was taken by employing soxhlet method
for extraction. This fat extract was then converted into their fatty acid methyl esters
(FAMEs) which were then run in a chromatogram to identify the fatty acid (FA)
peaks against those of fatty acid standards. (Table 4.II.6). The results per 100g of
French fries indicate that the total fat content was 8.5g, the SFA was more than 50%
of the total fat (5.4g/ 100g food), while the cis-MUFA, cis-PUFA and the cis-total
unsaturated fatty acids (cis-TUFA) levels were 2.09g, 1.0g and 3.1g respectively. No
detectable levels of TFA were present in the pre-fried French fries, indicating that the
test food was free of trans fatty acids (0.0g).
Table 4.II.6: Fatty Acid Profile Including TFA for Pre-fried French Fries (test
food)
Fatty Acid Profile g/ 100g of Pre-fried French fries
Total Fat 8.5
Saturated fatty Acid 5.4
cis-MUFA 2.09
cis-PUFA 1.0
cis-TUFA 3.1
TFA 0.0
209
4.II.2.2 Fatty Acid profile of fat/ oil samples subjected to heating/ re-
heating and frying in heated/ re-heated oils samples
All the unheated edible oils under study had high levels of cis-TUFA, ranging
between 67.3 g/ 100g (refined groundnut oil; ROGF) to 88.6 g/ 100g (refined canola
oil; ROC), moderate to low levels of SFA (9.7 g/ 100g refined canola oil; 30.04g/
100g refined groundnut oil) and the TFA being in negligible amounts ≈ 0.0g/ 100g
(refined olive, groundnut and soybean oil) to 1.6g/ 100g refined canola oil. According
to Tsuzuki (2011), fresh purified edible oil contains low levels of trans fatty acids but
their amount may change when used for cooking and frying. On the other hand the
unheated edible fats under study had substantial amount of SFA and cis-TUFA. The
TFA content of these fats showed a wide variation with desi ghee containing 0.68g/
100g while partially hydrogenated vegetable oil (PHVOD) containing as high as
13.9g/ 100g. A comparison of the fatty acid profile including trans fatty acid of the
unheated fat/ oil samples indicated the change in the fatty acid profile of oil samples
subjected to heating/ re-heating with or without frying the food item.
When the fats/ oils were heated at 180ºC, it was observed that, overall there was an
increase in the SFA and TFA levels with a decrease in the levels of cis-TUFA. Thus
the direct effect of frying or mere exposure to high temperature resulted in the
conversion of cis-TUFA to SFA and TFA, therefore, contributing to a manifold
increase in the levels of TFA.Further when these fats/ oils were re-heated after
cooling down to room temperature, since these had already been heated to 220ºC
earlier, even re-heating up to 180ºC increased the SFA and TFA and decreased the
cis-TUFA content. This change was marginal in most of the oil samples but more
pronounced in the case of fat samples (PHVOD and DGM). However, re-heating
these fat/ oil samples to 220ºC drastically increased the levels of SFA and TFA, with
decreasing levels of cis-TUFA.
On the other hand when frying was carried out in the select fat/ oil samples at 180ºC
and 220ºC, the trend was quite similar to that of heated fat/ oil samples i.e. the SFA
and TFA increased with subsequent frying cycles while the concentration of cis-
TUFA decreased. However, it was noted that the increase in the concentration of TFA
and SFA was not as high as that in the case of heated fat/ oil samples. This difference
210
in the concentrations of SFA, TFA and cis-TUFA could perhaps be attributed to the
test food and the possible mechanism could be the selective absorption/ retention of
SFA and TFA by the food being fried.
The result of this study are not in line with that of a similar study by Bansal et al
(2009), wherein the oil samples undergoing frying showed higher levels of TFA as
compared to the heated oil samples, which the authors have attributed to the TFA
content of the test food being fried. In the present study however, the test food being
free of trans fatty acid (as per the laboratory analysis) could not have contributed to
the TFA in the oil.
4.II.2.2a Fatty Acid profile of Refined groundnut oil sample (ROGF) subjected to
heating/ re-heating and frying in heated/ re-heated oils samples
Refined groundnut oil (ROGF), which is one of the most preferred oil for deep fat
frying at commercial level, when tested for its fatty acid profile including TFA before
subjecting to the heat treatment revealed that the SFA was slightly less than half of
cis-TUFA (SFA- 30.04g/ 100g oil; cis-TUFA- 67.33g/ 100g oil) while TFA was
almost non-existent. After the first heating to 180ºC, the SFA increased by 27.2 per
cent (38.2g/ 100g), while cis-TUFA decreased by 11.2 per cent (59.8g/ 100g), while
TFA interestingly not present initially registered a manifold increase from 0 to 1.6g/
100g (Table 4.II.7). This clearly demonstrates the direct effect of heat on the fatty
acid profile of the oil where in cis-TUFA is getting converted to trans fatty acids as
well as saturated fatty acids.
When the same oil sample was heated and maintained at 220ºC, the SFA and TFA
levels increased to 40.5g/ 100g and 2.10g/ 100 g, pointing to a further increase of 6.0
and 31.3 per cent respectively. On the other hand the cis-TUFA decreased to 55.0g/
100g registering a decrease of 8 per cent. This shows that when the oil is heated to a
higher temperature it increases the formation of TFA.
The same oil sample after heating up to 220ºC and subsequently cooling down to
room temperature was re-heated to 180ºC demonstrated a 9.5 per cent further
increase in the levels of TFA (2.30g/ 100g) and 6.7 per cent increase in the levels of
SFA (43.2g/ 100g), while the cis-TUFA decreased by 14.2 per cent (47.2g/ 100g).
211
This indicates that on subsequent cooling and re-heating of oil even at 180ºC, there is
an increase in the TFA levels. This marginal change in the levels of SFA, cis-TUFA
and TFA is because the oil sample was already exposed to a higher temperature of
220ºC and even re-heating it to 180ºC had an effect, though fringy. Thus the effect of
re-heating at 180ºC could perhaps be attributed more to even the duration of heating
rather than temperature alone. When the same re-heated oil sample was further re-
heated and maintained at 220ºC, compared to the re-heating cycle at 180ºC, it showed
an increase of 11.8 per cent in the levels of SFA (48.3g/ 100g) and 95.6 per cent in the
levels of TFA (4.5g/ 100g) while the cis-TUFA decreased by 0.9 per cent (46.8g/
100g). Compared to heating at 220ºC, reheating the same oil to 220ºC showed a
drastic increase in the TFA levels (114.3%), SFA increased by 19.3 per cent; while
cis-TUFA decreased by 14.9 per cent. Thus the effect of re-heating is rather
detrimental to the oil quality and maximum on TFA.
Similar to the effect of heating, the refined groundnut oil sample when used for
frying, registered an increase in the SFA and TFA contents, while the cis-TUFA
levels decreased. However, in comparison to the oil samples heated at 180ºC, the oil
sample used for frying at 180ºC (first frying cycle) had a 2.9 per cent lower level of
SFA, a 6.3 per cent lower level of TFA with marginally lower levels of cis-TUFA (0.7
%). This difference in the concentrations of SFA, TFA and cis-TUFA could perhaps
be attributed to the test food and the possible mechanism could be the selective
absorption/ retention of SFA and TFA by the food being fried. In a study on
characteristics and compositions of oils during deep fat frying, Tyagi and Vasishtha
(1996) reported an apparent increase in saturated fatty acids content and decrease in
unsaturated fatty acid content as frying time increased.
When the same oil sample was used for frying at 220ºC (second frying cycle), the
fatty acid composition revealed a 7.3 per cent increase in SFA (39.8g/ 100g) and 34.0
per cent increase in TFA content (2.01g/ 100g), while the cis-TUFA (53.4g/ 100g)
decreased by 10.1 per cent as compared to frying at 180ºC (first frying cycle). When
the fatty acid profile of the oil sample used for frying at 220ºC was compared to the
oil samples heated at 220ºC, the results indicated that the oil samples undergoing
second batch of frying at 220ºC showed lower levels of SFA (39.8g/ 100g), TFA
(2.01g/ 100g) as well as cis-TUFA (53.4g/ 100g) in comparison to their heated
212
counterparts. This once again is a pointer that perhaps the test food is selectively
absorbing/ retaining higher levels of SFA and TFA from the oil samples.
The fatty acid profile of the third frying cycle carried out in oil sample subjected to
reheating up to 180ºC (after cooling down to room temperature) demonstrated an
increase of 3.1 per cent in SFA (41.0g/ 100g), 4.5 per cent in TFA (2.10g/ 100g) and
1.5 per cent even in cis-TUFA (54.2g/ 100g) as compared to the fatty acid profile of
oil sample used for frying at 220ºC. It was interesting to note an increase in the
concentration of cis-TUFA, which otherwise was demonstrating a decrease in all the
oil samples undergoing heating or frying procedures. The only possible reason could
be attributed to the cis-TUFA of the test food being fried. In comparison to re-heating,
the oil sample used for re-frying at 180ºC had lower levels of SFA and TFA which are
comparable to the earlier results however, the levels of cis-TUFA were higher. This
shows that the test food was selectively absorbing/ retaining the TFA and SFA from
the oil and in turn was contributing to the cis-TUFA content of the oil.
At the end of the fourth frying cycle carried out in oil re-heated at 220ºC, there was a
10.6 per cent increase in SFA (45.4g/ 100g) and 76.2 per cent increase in the content
of TFA (3.7g/ 100g) as compared to the third frying cycle (frying in re-heated oil at
180ºC), while the cis-TUFA decreased by 8.9 per cent (49.4g/ 100g). Further
compared to frying at 220ºC, re-using the same oil for frying again at 220ºC (after a
cooling to room temperature) there was an increase in the SFA levels by 14.1 per
cent, and that of TFA levels by 84.1 per cent; while the cis-TUFA decreased
marginally by 7.5 per cent. This further accentuates the theory of selective absorption
and retention of SFA and TFA by the test food.
Comparison of the fatty acid profile of the oil used for re-frying at 220ºC with that of
the oil re-heated to 220ºC indicated that in the former case the levels of SFA and TFA
were not as high as in the latter. However,, the cis-TUFA showed an increase of 5.6
per cent, further pointing to the theory of selective absorption/ retention of SFA and
TFA by the test food, while at the same time contributing towards the cis-TUFA level
in the oil. This shows that during heating and frying there is an increase in the levels
of SFA and TFA while the cis-TUFA decreases (Figure 4.II.5).
213
Table 4.II.7: Fatty Acid Profile (including TFA) of Refined Groundnut oil
(ROGF) before and after subjecting to heating/ re-heating and frying in heated/
re-heated oil (g/ 100g)
Treatment Fatty acid profile
SFA cis – TUFA TFA UNHEATED 30.04 67.33 0.00 HEATED AT 180ºC 38.20 59.80 1.60 Change (% Change) 8.16 (27.2%) 7.53 (11.2%) 1.60 HEATED AT 180ºC 38.20 59.80 1.60 HEATED AT 220ºC 40.50 55.00 2.10 Change (% Change) 2.30 (6.0%) 4.80 (8.0%) 0.50 (31.3%) HEATED AT 220ºC 40.50 55.00 2.10 Re-HEATED AT 180ºC 43.20 47.20 2.30 Change (% Change) 2.70 (6.7%) 7.80 (14.2%) 0.20 (9.5%) Re-HEATED AT 180ºC 43.20 47.20 2.30 Re-HEATED AT 220ºC 48.30 46.80 4.50 Change (% Change) 5.10 (11.8%) 0.40 (0.9%) 2.20 (95.6%) HEATED AT 220ºC 40.50 55.00 2.10 Re-HEATED AT 220ºC 48.30 46.80 4.50 Change (% Change) 7.80 (19.3%) 8.20 (14.9%) 2.40 (114.3%) UNHEATED 30.04 67.33 0.00 FRIED AT 180ºC 37.10 59.40 1.50 Change (% Change) 7.06 (23.5%) 7.93 (11.8%) 1.50 FRIED AT 180ºC 37.10 59.40 1.50 FRIED AT 220ºC 39.80 53.40 2.01 Change (% Change) 2.70 (7.3%) 6.00 (10.1%) 0.51 (34.0%) FRIED AT 220ºC 39.80 53.40 2.01 FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 Change (% Change) 1.24 (3.1%) 0.80 (1.5%) 0.09 (4.5%) FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 4.36 (10.6%) 4.80 (8.9%) 1.60 (76.2%) FRIED AT 220ºC 39.80 53.40 2.01 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 5.60 (14.1%) 4.00 (7.5%) 1.69 (84.1%) HEATED AT 180ºC 38.20 59.80 1.60 FRIED AT 180ºC 37.10 59.40 1.50 Change (% Change) 1.10 (2.9%) 0.40 (0.7%) 0.10 (6.3%) HEATED AT 220ºC 40.50 55.00 2.10 FRIED AT 220ºC 39.80 53.40 2.01 Change (% Change) 0.70 (1.7%) 1.60 (2.9%) 0.09 (4.3%) Re-HEATED AT 180ºC 43.20 47.20 2.30 FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 Change (% Change) 2.16 (5.0%) 7.00 (14.8%) 0.20 (8.7%) Re- HEATED AT 220ºC 48.30 46.80 4.50 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 2.90 (6.0%) 2.60 (5.6%) 0.80 (17.8%)
214
4.II.2b Fatty Acid profile of Refined Olive oil (ROOLP) subjected to heating/ re-
heating and frying in heated/ re-heated oils samples
Refined Olive oil (ROOLP), which is quite appealing because of its high MUFA
content, especially among the upper middle income group and is often regarded as a
nutritionists choice of oil was also exposed to similar experimentation. The unheated
oil revealed an initial composition of SFA- 14.4g/100g; cis-TUFA- 85.5g, while the
TFA levels were undetectable as in the case of groundnut oil. However, after the first
episode of heating and maintaining the oil to 180ºC the level of SFA increased by29.9
per cent (18.7g/ 100g) while the levels of cis-TUFA decreased by 11.5 per cent
(75.7g/ 100g). This episode of heating also resulted in the formation of TFA (0.42g/
100g) which were absent initially, depicting a manifold increase in its levels (Table
4.II.8, Figure 4.III.6).
When the same oil sample was again heated and maintained at 220ºC, the level of
SFA and TFA further increased by 11.2 per cent (20.8g/ 100g) and 111.9 per cent
(0.89g/ 100g) respectively, while that of cis-TUFA decreased by 5.9 per cent (71.2g/
100g). This re-emphasises the increase in formation of TFA on exposure to high
temperature. When the same oil sample was re-heated at 180ºC, (after cooling down
to RT) the level of SFA increased by 15.9 per cent (24.1g/ 100g) and TFA increased
by 23.6 per cent (1.10g/ 100g), while cis-TUFA registered a marginal decrease of 1.7
per cent (70.0g/ 100g). As already explained, this marginal difference in the fatty acid
profile of the oil was because the oil was already exposed to a higher temperature of
220ºC (during second batch of heating).
However, when the same oil sample was further re-heated to 220ºC, the fatty acid
profile showed a 236.4 per cent increase in the levels of TFA (3.70g/ 100g), and SFA
increased by 6.6 per cent (25.7g/ 100g), while cis-TUFA demonstrated a decrease of
1.3 per cent (69.1g/100g). Compared to oil sample heated to 220ºC, re-heating the oil
to 220ºC indicated a 315.7 per cent increase in TFA (3.7g/ 100g) and 23.6 per cent
increase in SFA (25.7g/ 100g), while cis-TUFA showed a decrease of 3.0 per
cent(69.1g/100g).
215
Table 4.II.8: Fatty Acid Profile (including TFA) of Refined Olive oil (ROOLP)
before and after subjecting to heating/ re-heating and frying in heated/ re-heated
oil (g/ 100g)
Treatment Fatty Acid Profile
SFA cis- TUFA TFA
UNHEATED 14.40 85.50 0.00
HEATED AT 180ºC 18.70 75.70 0.42
Change (% Change) 4.30 (29.9%) 9.80 (11.5%) 0.42
HEATED AT 180ºC 18.70 75.70 0.42
HEATED AT 220ºC 20.80 71.20 0.89
Change (% Change) 2.10 (11.2%) 4.50 (5.9%) 0.47 (111.9%)
HEATED AT 220ºC 20.80 71.20 0.89
Re-HEATED AT 180ºC 24.10 70.01 1.10
Change (% Change) 3.30 (15. %9) 1.19 (1.7%) 0.21 (23.6%)
Re-HEATED AT 180ºC 24.10 70.01 1.10
Re-HEATED AT 220ºC 25.70 69.10 3.70
Change (% Change) 1.60 (6.6%) 0.91 (1.3%) 2.60 (236.4%)
HEATED AT 220ºC 20.80 71.20 0.89
Re-HEATED AT 220ºC 25.70 69.10 3.70
Change (% Change) 4.90 (23.6%) 2.10 (3.0%) 2.81 (315.7%)
UNHEATED 14.40 85.50 0.00
FRIED AT 180ºC 16.70 80.70 0.28
Change (% Change) 2.30 (16.0%) 4.80 (5.6%) 0.28
FRIED AT 180ºC 16.70 80.70 0.28
FRIED AT 220ºC 19.60 77.20 0.51
Change (% Change) 2.90 (17.4%) 3.50 (4.3%) 0.23 (82.1%)
FRIED AT 220ºC 19.60 77.20 0.51
FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40
Change (% Change) 2.70 (13.8%) 3.20 (4.2%) 0.89 (174.5%)
FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40
FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60
Change (% Change) 0.90 (4.0%) 4.74 (6.4%) 2.20 (157.1%)
FRIED AT 220ºC 19.60 77.20 0.51
FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60
Change (% Change) 3.60 (18.4%) 7.94 (10.3%) 3.09 (605.9%)
HEATED AT 180ºC 18.70 75.70 0.42
FRIED AT 180ºC 16.70 80.70 0.28
Change (% Change) 2.00 (10.7%) 5.00 (6.6%) 0.14 (33.3%)
HEATED AT 220ºC 20.80 71.20 0.89
FRIED AT 220ºC 19.60 77.20 0.51
Change (% Change) 1.20 (5.8%) 6.00 (8.4%) 0.38 (42.7%)
Re-HEATED AT 180ºC 24.10 70.01 1.10
FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40
Change (% Change) 1.80 (7.5%) 3.99 (5.7%) 0.30 (27.3%)
Re- HEATED AT 220ºC 25.70 69.10 3.70
FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60
Change (% Change) 2.50 (9.7%) 0.16 (0.2%) 0.10 (2.7%)
216
When the olive oil sample from the same batch was used for frying after heating and
maintaining the oil at 180ºC, the fatty acid composition showed a trend similar to that
of heated oil sample, i.e. the levels of SFA increased (16.7g/ 100g) and cis-TUFA
decreased (80.7g/ 100g), indicating an per cent change of 16.0 and 5.6 respectively as
compared to the unheated oil sample, while the TFA content, which was absent
initially appeared at the level of 0.28g/ 100g. However, in comparison to the oil
samples heated and maintained at 180ºC, the oil sample used for frying after heating
and maintaining at 180ºC showed 10.7 per cent lower levels of SFA, 33.3 per cent
lower levels of TFA and 6.6 per cent higher level of cis-TUFA. This clearly
demonstrates the interchange of the fatty acids from the test food.
After the second frying cycle carried out in heated oil sample maintained at 220ºC,
the SFA and TFA levels further increased by 17.4 (19.6g/ 100g) and 82.1 (0.51g/
100g) per cent respectively, while the cis-TUFA registered a decrease of 4.3 per cent
(77.2g/ 100g). As compared to the oil sample heated at 220ºC, the oil used for frying
at 220ºC showed lower levels of SFA and TFA, pointing to a percentage change of
5.8 and 42.7 respectively. However, the cis-TUFA level in the oil sample used for
frying was higher (8.4%) than that present in oil sample heated at 220ºC. This further
establishes the point of selective absorption/ retention of SFA and TFA by the test
food and in turn contributing to the cis-TUFA content of the oil.
Further, when frying was done in the same oil sample after re-heating and maintaining
the oil at 180ºC (third frying cycle; after cooling down to room temperature), the fatty
acid profile of the oil depicted a 13.8 per cent increase in the SFA (22.3g/ 100g) and
174.5 per cent increase in TFA levels (1.40g/ 100g), while cis-TUFA depicted a
decrease of 4.2 per cent (74.0g/ 100g) as compared to the 2nd
frying cycle. Further, in
comparison to the re-heated oil at 180ºC, the oil used for re-frying at 180ºC, indicated
lower levels of SFA, while the level of cis-TUFA were higher. However, when the
same oil sample was further re-heated to 220ºC for frying (fourth frying cycle), the
SFA increased by 4.0 per cent (23.2g/ 100g), while TFA increased to more than
double, registering an increase of 157.1 per cent (3.60g/ 100g), while cis-TUFA
decreased by 6.4 per cent (69.3g/ 100g). Compared to frying at 220ºC, re-using the
same oil for frying at 220ºC (after a cooling the oil to RT) showed an increase in the
217
SFA (23.2 g/100g) levels by 18.4 per cent, while TFA (3.6g/ 100g) levels increased
by 605.9 per cent.
Compared to the fatty acid profile of the re-heated oil sample at 220ºC, the oil used
for re-frying at 220ºC depicted a 9.7 per cent decrease in the levels of SFA, while
TFA decreased by 2.7 per cent. However, the cis-TUFA demonstrated an increase of
0.2 per cent, further pointing to the theory of selective absorption/ retention of SFA
and TFA by the test food, while at the same time contributing towards the cis-TUFA
level in the oil. This also highlights that refined olive oil, although is high in MUFA
but this positive attribute makes it more susceptible to be converted to trans isomers
during heating/ frying, thus it is suggested that it should not be used for re-frying.
4.II.2c Fatty Acid profile of Refined Soybean oil (ROSB) subjected to heating/ re-
heating and frying in heated/ re-heated oils samples
Refined Soybean oil (ROSB), which is one of the popularly used frying oil both at
commercial as well as household level, when tested for its fatty acid profile including
TFA before subjecting to heat treatment revealed an initial composition of SFA;
17.9g/ 100g oil, cis-TUFA; 82.08 g/100g oil while the TFA was not found in the
detectable range. After the first heating and maintaining the oil sample at 180ºC, the
SFA level increased by 12.1 per cent (20.06g/ 100g), while the cis-TUFA decreased
by 10.6 per cent (73.4g/ 100g). Trans fatty acid, which were undetectable in the
unheated oil sample were also formed (0.6g/ 100g) depicting a manifold increase
(Table 4.II.9, Figure 4.II.7).
When the same oil sample was heated to 220ºC the SFA increased to 21.4 g/ 100g,
while TFA increased by more than double (1.70g/ 100g), depicting an increase of 6.7
and 283.3 per cent respectively. On the other hand the level of cis-TUFA (72.9g/
100g) decreased by 0.7 per cent. Further when the same oil was re-heated to 180ºC
(after cooling down to RT), the SFA increased by 12.6 per cent (24.1g/ 100g), while
TFA registered an increase of 23.53 per cent (2.1g/ 100g), with cis-TUFA
demonstrating a marginal decrease of 2.7 per cent (70.9g/ 100g). When the same oil
sample was further re-heated to 220ºC, the TFA content increased by 76.2 per cent
(3.7g/ 100g) and SFA increased by 9.5 per cent (26.4g/ 100g), while cis-TUFA
decreased by of 6.1 per cent (66.6g/ 100g). Comparing the oil sample heated at 220ºC
to the oil sample re-heated at 220ºC, it was observed that the re-heated oil sample
218
depicted a much higher increase in the levels of SFA and TFA registering a per cent
increase of 23.4 per cent and 117.7 per cent respectively, while cis-TUFA
demonstrated a decrease of 8. 6 per cent.
Similar to the effect of heating, the refined soybean oil sample when used for frying,
after the first frying cycle at 180ºC, registered an increase in the levels of both SFA
(19.9g/ 100g) and TFA (0.36g/ 100g) with a decrease in the levels of cis-TUFA
(77.0g/ 100g), however, in comparison to the oil samples heated at 180ºC the oil
sample used for frying at 180ºC pointed to a 0.8 per cent and 40.0 per cent lower
levels of SFA and TFA with 4.9 per cent higher levels of cis-TUFA. When the same
oil sample was used for frying at 220ºC (second frying cycle), the fatty acid
composition revealed an increase of 9.1 per cent for SFA (21.7g/ 100g) and 316.7 per
cent for TFA (1.50g/ 100g), while the cis-TUFA (72.9g/ 100g) reported a decrease of
5.4 per cent as compared to the first frying cycle at 180ºC. Similar to the result of first
batch of frying at 180ºC, the oil samples undergoing second batch of frying at 220ºC
also showed lower levels of TFA (1.50g/100g) in compared to the oil samples heated
at 220ºC.
When the third frying cycle was carried out, in re-heated oil sample maintained at
180ºC (after cooling down the oil to RT), the oil even though, had attained a higher
temperature of 220ºC during second frying cycle, still demonstrated an increase of 7.4
per cent in levels of SFA (23.3g/ 100g) and 33.3 per cent in the levels of TFA as
compared to the oil sample used for second frying cycle (220ºC). In comparison to the
oil re-heated at 180ºC, the re-heated oil sample undergoing frying at 180ºC had lower
levels of SFA and TFA which are comparable to the previous results however, the
levels of cis-TUFA were higher. This also indicates that the test food was selectively
absorbing the TFA and SFA from the oil and in turn was contributing to the cis-
TUFA content of the oil.
Further, at the end of the fourth frying cycle carried out in re-heated oil at 220ºC
there was an increase of 10.7 per cent in the levels of SFA (25.8g/ 100g) and 60.0 per
cent in the levels of TFA (3.2g/ 100g) as compared to the third frying cycle at 180ºC,
while the cis-TUFA (66.3g/ 100g) decreased by 8.8 per cent. Compared to frying at
220ºC, re-using the same oil for frying again at 220ºC (after a cooling the oil to RT)
demonstrated an increase in SFA by 18.9 per cent, while, TFA increased by 113.3 per
cent and the cis-TUFA decreased by 9.1 per cent. Compared to the fatty acid profile
of the oil re-heated to 220ºC, the re-heated oil used for frying at 220ºC, indicated a 2.3
219
per cent decrease in the levels of SFA, while TFA showed a decrease of 13.5 per cent.
However, the cis-TUFA showed a marginal decrease of 0.5 per cent.
Table 4.II.9: Fatty Acid Profile (including TFA) of Refined Soybean oil (ROSB)
before and after subjecting to heating/ re-heating and frying/ re-frying (g/ 100g)
Treatment Fatty Acid profile SFA cis – TUFA TFA
UNHEATED 17.90 82.08 0.00 HEATED AT 180ºC 20.06 73.40 0.60 Change (% Change) 2.16 (12.1%) 8.68 (10.6%) 0.60 HEATED AT 180ºC 20.06 73.40 0.60 HEATED AT 220ºC 21.40 72.90 1.70 Change (% Change) 1.34 (6.7%) 0.50 (0.7%) 1.10 (283.3%) HEATED AT 220ºC 21.40 72.90 1.70 Re-HEATED AT 180ºC 24.10 70.90 2.10 Change (% Change) 2.70 (12.6%) 2.00 (2.7%) 0.40 (23.5%) Re-HEATED AT 180ºC 24.10 70.90 2.10 Re-HEATED AT 220ºC 26.40 66.60 3.70 Change (% Change) 2.30 (9.5%) 4.30 (6.1%) 1.60 (76.2%) HEATED AT 220ºC 21.40 72.90 1.70 Re-HEATED AT 220ºC 26.40 66.60 3.70 Change (% Change) 5.00 (23.4%) 6.30 (8.6%) 2.00 (117.7%) UNHEATED 17.90 82.08 0.00 FRIED AT 180ºC 19.90 77.02 0.36 Change (% Change) 2.00 (11.2%) 5.06 (6.2%) 0.36 FRIED AT 180ºC 19.90 77.02 0.36 FRIED AT 220ºC 21.70 72.90 1.50 Change (% Change) 1.80 (9.1%) 4.12 (5.4%) 1.14 (316.7%) FRIED AT 220ºC 21.70 72.90 1.50 FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 Change (% Change) 1.60 (7.4%) 0.20 (0.3%) 0.50 (33.3%) FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 2.50 (10.7%) 6.40 (8.8%) 1.20 (60.0%) FRIED AT 220ºC 21.70 72.90 1.50 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 4.10 (18.9%) 6.60 (9.1%) 1.70 (113.3%) HEATED AT 180ºC 20.06 73.40 0.60 FRIED AT 180ºC 19.90 77.02 0.36 Change (% Change) 0.16 (0.8%) 3.62 (4.9%) 0.24 (40.0%) HEATED AT 220ºC 21.40 72.90 1.70 FRIED AT 220ºC 21.70 72.90 1.50 Change (% Change) 0.30 (1.4%) 0.00 (0.0%) 0.20 (11.8%) Re-HEATED AT 180ºC 24.10 70.90 2.10 FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 Change (% Change) 0.80 (3.3%) 1.80 (2.5%) 0.10 (4.8%) Re- HEATED AT 220ºC 26.40 66.60 3.70 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 0.60 (2.3%) 0.30 (0.5%) 0.50 (13.5%)
220
4.II.2d Fatty Acid profile of Refined Canola Oil (ROC) subjected to heating/ re-
heating and frying in heated/ re-heated oils samples
Refined Canola Oil (ROC), which is being perceived as one of the best oils
available, with fatty acid profile similar to that of mustard oil and almost negligible
erucic acid content, revealed an initial composition of SFA- 9.7g/ 100g; cis-TUFA-
88.6g/ 100g and TFA; 1.6g/ 100g. It is to be noted that amongst all the refined oils
subjected to heating/ re-heating and frying in the present study, only refined canola oil
had TFA present in it, rest all were almost free of TFA initially. After the first batch
of heating at 180ºC, the SFA level increased by 12.4 per cent (10.9g/ 100g), while
cis-TUFA decreased by 6.6 per cent (82.8g/ 100g). Trans fatty acid, which were
already quite high in the unheated oil sample as compared to other refined oils, also
increased to 2.3g/ 100g, depicting an increase of 43.8 per cent (Table 4.II.10, Figure
4.II.8). When the same oil sample was heated again to 220ºC the SFA increased to
12.4g/ 100g, while TFA level increased to 2.9g/ 100g pointing to an increase of 13.8
and 26.1 per cent respectively. On the other hand cis-TUFA decreased by 3.6 per cent
(79.8g/ 100g).
Further when the same oil was re-heated to 180ºC (after cooling down to RT), the
SFA content increased by 9.7 per cent (13.6g/ 100g) and TFA levels increased by
13.8 per cent (3.3g/ 100g), while cis-TUFA registered a marginal decrease of 2.1 per
cent (78.1g/ 100g). However, when the same oil was re-heated to 220ºC, the TFA
increased by 27.3 per cent (4.2g/100g) and SFA increased by 36.0 per cent (18.5g/
100g) while, cis-TUFA (77.2g/ 100g) registered a decrease of 1.1 per cent. Compared
to the oil sample heated at 220ºC to the oil sample re-heated at 220ºC, it was observed
that the re-heated oil sample depicted a much higher increase in the levels of SFA and
TFA registering a per cent increase of 49.2 and 44.8 respectively, while cis-TUFA
demonstrated a decrease of 3.3 per cent.
Similar to the effect of heated oil samples, the refined canola oil sample used for
frying, after the first frying cycle at 180ºC, depicted an increase in the levels of both
SFA (10.6g/ 100g) and TFA (2.09g/ 100g), while levels of cis-TUFA (87.2g/ 100g)
decreased by 1.6 per cent. In comparison to the oil samples heated at 180ºC the oil
sample used for frying at 180ºC pointed to 2.8 per cent and 9.1 per cent lower levels
of SFA and TFA while the levels of cis-TUFA increased by 5.3 per cent. When the
same oil sample was used for frying at 220ºC (second frying cycle), the fatty acid
composition revealed an increase of 16.0 per cent in SFA (12.3g/ 100g) and 24.4 per
221
cent in TFA (2.6g/ 100g), while the cis-TUFA (84.5g/ 100g) reported a decrease of
3.1 per cent as compared to the first frying cycle at 180ºC. In comparison to the oil
sample heated at 220ºC, the oil sample used for frying 220ºC demonstrated 10.3 per
cent lower levels of TFA (2.6g/100g).
The third frying cycle carried out, in the oil sample subjected to re-heating up to
180ºC (after cooling down to RT), the fatty acid profile demonstrated an increase of
6.5 per cent in SFA (13.1g/ 100g), 23.1 per cent in TFA (3.20g/ 100g), while the cis-
TUFA (75.2g/ 100g) decreased by 11.0 per cent as compared the fatty acid profile of
the oil sample used for frying at 220ºC (second frying cycle). In comparison to re-
heating, the oil sample undergoing re-frying at 180ºC had lower levels of SFA, cis-
TUFA and TFA.
At the end of the fourth frying cycle, carried out in oil re-heated at 220ºC, there was
27.5 per cent increase in SFA (16.7g/ 100g) and 21.9 per cent increase in TFA (3.9g/
100g) as compared to the third frying cycle in re-heated oil at 180ºC, while the cis-
TUFA (72.3g/ 100g) decreased by 3.9 per cent. Further, compared to frying at 220ºC,
re-using the same oil for frying again at 220ºC (after a cooling to RT) showed an
increase in the SFA levels by 35.8 per cent, while TFA levels increased by 50.0 per
cent and the cis-TUFA decreased by 14.4 per cent. This further stresses on the theory
of selective absorption/ retention of SFA and TFA by the test food. Comparison of the
fatty acid profile of the oil used for re-frying at 220ºC with that of the oil used for re-
heating to 220ºC indicated that in the former case the levels of SFA and TFA were not
as high as in the heated oil samples.
222
Table 4.II.10: Fatty Acid Profile (including TFA) of Refined Canola oil (ROC) before
and after subjecting to heating/ re-heating and frying/ re-frying (g/ 100g) Treatment Fatty Acid Profile
SFA cis- TUFA TFA
UNHEATED 9.70 88.60 1.60
HEATED AT 180ºC 10.90 82.80 2.30
Change (% Change) 1.2 (12.4%) 5.8 (6.6%) 0.7 (43.8%)
HEATED AT 180ºC 10.90 82.80 2.30
HEATED AT 220ºC 12.40 79.80 2.90
Change (% Change) 1.5 (13.8%) 3 (3.6%) 0.6 (26.1%)
HEATED AT 220ºC 12.40 79.80 2.90
Re-HEATED AT 180ºC 13.60 78.09 3.30
Change (% Change) 1.2 (9.7%) 1.71 (2.1%) 0.40 (13.8%)
Re-HEATED AT 180ºC 13.60 78.09 3.30
Re-HEATED AT 220ºC 18.50 77.20 4.20
Change (% Change) 4.90 (36.0%) 0.89 (1.1%) 0.90 (27.3%)
HEATED AT 220ºC 12.40 79.80 2.90
Re-HEATED AT 220ºC 18.50 77.20 4.20
Change (% Change) 6.10 (49.2%) 2.60 (3.3%) 1.30 (44.8%)
UNHEATED 9.70 88.60 1.60
FRIED AT 180ºC 10.60 87.20 2.09
Change (% Change) 0.90 (9.3%) 1.40 (1.6%) 0.49 (30.6%)
FRIED AT 180ºC 10.60 87.20 2.09
FRIED AT 220ºC 12.30 84.50 2.60
Change (% Change) 1.70 (16.0%) 2.70 (3.1%) 0.51 (24.4%)
FRIED AT 220ºC 12.30 84.50 2.60
FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20
Change (% Change) 0.80 (6.5%) 9.30 (11.0%) 0.60 (23.1%)
FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20
FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90
Change (% Change) 3.60 (27.5%) 2.90 (3.9%) 0.70 (21.9%)
FRIED AT 220ºC 12.30 84.50 2.60
FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90
Change (% Change) 4.40 (35.8%) 12.20 (14.4%) 1.30 (50.0%)
HEATED AT 180ºC 10.90 82.80 2.30
FRIED AT 180ºC 10.60 87.20 2.09
Change (% Change) 0.30 (2.8%) 4.40 (5.3%) 0.21 (9.1%)
HEATED AT 220ºC 12.40 79.80 2.90
FRIED AT 220ºC 12.30 84.50 2.60
Change (% Change) 0.10 (0.8%) 4.70 (5.9%) 0.30 (10.3%)
Re-HEATED AT 180ºC 13.60 78.09 3.30
FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20
Change (% Change) 0.50 (3.7%) 2.89 (3.7%) 0.10 (3.0%)
Re- HEATED AT 220ºC 18.50 77.20 4.20
FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90
Change (% Change) 1.80 (9.7%) 4.90 (6.4%) 0.30 (7.1%)
223
4.II.2e Fatty Acid profile of Partially hydrogenated vegetable oil (PHVOVD)
subjected to heating/ re-heating and frying in heated/ re-heated oils samples
Partially hydrogenated vegetable oil, also known as vanaspati, is the cheapest
substitute to desi ghee, and the biggest source of TFA in Indian diets. A need was felt
to understand the change in its fatty acid profile when exposed to subsequent heating/
re-heating and frying, therefore it was included in the present study. The unheated
sample of partially hydrogenated vegetable oil (PHVOVD), revealed that SFA and
cic-TUFA were almost equal (SFA- 41.1g/ 100g; cis-TUFA; 40.9g/ 100g), while the
TFA content was as high as 13.9 g/ 100g. When the fat sample was heated and
maintained at 180ºC, the SFA increased by 8.9 per cent (44.7g/ 100g), while cis-
TUFA decreased by 20.5 per cent (32.5g/ 100g). Though, the TFA content increased
by 9.4 per cent, its high initial concentration lead to higher levels, resulting in 15.2g
TFA/ 100g oil. On further heating the fat to 220ºC, SFA registered an increase of 9.4
per cent (48.9g/ 100g) and TFA increased by 5.9 per cent (16.1g/ 100g), while cis-
TUFA decreased by 2.8 per cent (Table 4.II.11 and Figure 4.II.9). When the fat was
further re-heated at 180ºC (after a cooling down to RT), the SFA levels increased by
3.1 per cent (50.4g/ 100g), while TFA increased by 11.2 per cent (17.9g/ 100g), on
the other hand cis-TUFA registered a decrease of 11.1 per cent (28.1g/ 100g). When
the same fat sample was re-heated to 220ºC SFA increased by 1.6 per cent (51.2g/
100g), TFA increased by 4.5 per cent (18.70g/ 100g) while cis-TUFA registered a
decrease of 6.8 per cent (26.2g/ 100g). As compared to heating at 220ºC, re-heating
the same sample to 220ºC increased the SFA and TFA by 4.7 and 16.1 per cent
respectively, while cis-PUFA decreased by 17.1 per cent.
Similar to the heated oil samples, the partially hydrogenated vegetable oil sample
used for frying, after the first frying cycle at 180ºC, demonstrated a per cent increase
of 9.4 and 5.8 respectively in the levels of both SFA (44.9g/ 100g) and TFA (14.70g/
100g). The cis-TUFA (32.3g/ 100g) registered a decrease of 21.0 per cent. In
comparison to the oil samples heated at 180ºC the oil sample used for frying at 180ºC
pointed to 3.3 per cent lower levels of TFA, while SFA and cis-TUFA levels almost
remained the same.
As compared to the first frying cycle at 180ºC, when the same oil sample was used for
frying at 220ºC (second frying cycle), the fatty acid composition registered an
224
increase of 6.5 per cent in SFA (47.8g/ 100g) and 7.5 per cent in TFA (15.8g/ 100g),
while the cis-TUFA (29.2g/ 100g) reported a decrease of 9.6 per cent. Similar to the
result of first frying cycle at 180ºC, the oil samples used for second frying cycle at
220ºC also showed lower levels of SFA, TFA as well as cis-TUFA, in comparison to
their heated counterparts, depicting a per cent decrease of 2.2, 7.6 and 1.9
respectively. This indicates the likely hood of the test food absorbing and retaining
these fats from the oil samples. However, explanation of this aspect requires further
studies.
The third frying cycle carried out, in the fat sample subjected to re-heating up to
180ºC (after cooling down to RT and re-heating it again to 180ºC), demonstrated a
per cent increase of 4.4 in SFA (49.9g/ 100g) and 7.6 in TFA (17.00g/ 100g), while
the cis-TUFA decreased by 4.8 per cent (27.8g/ 100g) as compared the fatty acid
profile of oil sample used for second frying cycle (220ºC). In comparison to re-
heating, the fat sample used for frying in re-heated fat at 180ºC had lower levels of
SFA, cis-TUFA and TFA, pointing to a per cent decrease of 1.0, 1.1 and 5.0
respectively.
As compared to the third frying cycle, the fourth frying cycle carried out in fat re-
heated at 220ºC, there was 1.6 per cent increase in the levels of SFA (50.7g/ 100g)
and 9.4 per cent in the levels of TFA (18.60g/ 100g), while the cis-TUFA (25.6g/
100g) decreased by 7.9 per cent. In comparison to frying at 220ºC, re-using the same
fat for frying again at 220ºC (after a cooling the oil to RT) there was an increase in
SFA by 6.1 per cent, TFA increased by 17.7 per cent while, the cis-TUFA decreased
by 12.3 per cent.
Comparison of the fatty acid profile of the fat re-heated at 220ºC and the re-heated fat
used for frying at 220ºC it was observed that the latter depicted a 1.0 per cent decrease
in SFA, while TFA indicated a decrease of only 0.5 per cent. However, the cis-TUFA
showed a decrease of 2.3 per cent.
Previous studies have also demonstrated that when partially hydrogenated fats are
used, the formation of TFA is generally lower (Aro et al, 1998, Romero et al, 2000) as
has been observed in the present study, however, the high initial levels of TFA results
in a larger concentration of trans isomers in fried food
225
Table 4.II.11: Fatty Acid Profile (including TFA) of Partially Hydrogenated
Vegetable oil(PHVOD) before and after subjecting to heating/ re-heating and frying/
re-frying (g/ 100g)
Treatment Fatty Acid Profile
SFA cis-TUFA TFA UNHEATED 41.05 40.90 13.90 HEATED AT 180ºC 44.70 32.50 15.20 Change (% Change) 3.65 (8.9%) 8.40 (20.5%) 1.30 (9.4%) HEATED AT 180ºC 44.70 32.50 15.20 HEATED AT 220ºC 48.90 31.60 16.10 Change (% Change) 4.20 (9.4%) 0.90 (2.8%) 0.90 (5.9%) HEATED AT 220ºC 48.90 31.60 16.10 Re-HEATED AT 180ºC 50.40 28.10 17.90 Change (% Change) 1.50 (3.1%) 3.50 (11.1%) 1.80 (11.2%) Re-HEATED AT 180ºC 50.40 28.10 17.90 Re-HEATED AT 220ºC 51.20 26.20 18.70 Change (% Change) 0.80 (1.6%) 1.90 (6.8%) 0.80 (4.5%) HEATED AT 220ºC 48.90 31.60 16.10 Re-HEATED AT 220ºC 51.20 26.20 18.70 Change (% Change) 2.30 (4.7%) 5.40 (17.1%) 2.60 (16.1%) UNHEATED 41.05 40.90 13.90 FRIED AT 180ºC 44.90 32.30 14.70 Change (% Change) 3.85 (9.4%) 8.60 (21.0%) 0.80 (5.8%) FRIED AT 180ºC 44.90 32.30 14.70 FRIED AT 220ºC 47.80 29.20 15.80 Change (% Change) 2.90 (6.5%) 3.10 (9.6%) 1.10 (7.5%) FRIED AT 220ºC 47.80 29.20 15.80 FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 Change (% Change) 2.10 (4.4%) 1.40 (4.8%) 1.20 (7.6%) FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 0.80 (1.6%) 2.20 (7.9%) 1.60 (9.4%) FRIED AT 220ºC 47.80 29.20 15.80 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 2.90 (6.1%) 3.60 (12.3%) 2.80 (17.7%) HEATED AT 180ºC 44.70 32.50 15.20 FRIED AT 180ºC 44.90 32.30 14.70 Change (% Change) 0.20 (0.4%) 0.20 (0.6%) 0.50 (3.3%) HEATED AT 220ºC 48.90 31.60 16.10 FRIED AT 220ºC 47.80 29.20 15.80 Change (% Change) 1.10 (2.2%) 2.40 (7.6%) 0.30 (1.9%) Re-HEATED AT 180ºC 50.40 28.10 17.90 FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 Change (% Change) 0.50 (1.0%) 0.30 (1.1%) 0.90 (5.0%) Re- HEATED AT 220ºC 51.20 26.20 18.70 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 0.50 (1.0%) 0.60 (2.3%) 0.10 (0.5%)
226
4.II.2f Fatty Acid profile of Desi ghee (DGM) subjected to heating/ re-heating
and frying in heated/ re-heated oils samples
Desi ghee, is a class of clarified butter that originated in India and is commonly used
in Indian and South Asian cuisines and traditional foods. However, owing to its high
cost it is replaced by commercial food manufacturers. The unheated sample of Desi
ghee (DGM), revealed a fatty acid profile of SFA: 42.2g/ 100g; cis-TUFA: 52.1g/
100g, while the TFA content was 0.68g/ 100g. After the first heating to 180ºC, the
SFA increased by 2.1 per cent (43.1g/ 100g), TFA increased by 51.4 per cent (1.40g/
100g), while cis-TUFA decreased by 4.01 per cent (50.01g/ 100g).
On further heating the fat to 220ºC, SFA registered an increase of 7.0 per cent (46.1g/
100g) and TFA increased by 22.2 per cent (1.80g/ 100g), however, cis-TUFA showed
a decrease of 4.8 per cent (Table 4.II.12 and Figure 4.II.10). When the fat was re-
heated up to 180ºC (after a cooling down to RT), the SFA levels increased by 5.4 per
cent (48.6g/ 100g), while TFA increased by 66.7 per cent (3.00g/ 100g), cis-TUFA
also registered a decrease of 15.3 per cent (40.3g/ 100g). Further when the same fat
sample was re-heated to 220ºC, the SFA levels increased by 1.9 per cent (49.5g/
100g) and TFA content increased by 10.0 per cent (3.30g/ 100g), while cis-TUFA
demonstrated a decrease of 5.0 per cent (38.3g/ 100g). As compared to heating at
220ºC, re-heating the same fat sample to 220ºC increased the SFA and TFA by 7.4
and 83.3 per cent respectively, while cis-TUFA decreased by 19.5 per cent.
Similar to the heated oil samples, the desi ghee sample used for frying, after the first
frying cycle at 180ºC, demonstrated increase in the levels of SFA (43.01g/ 100g) and
TFA (1.20g/ 100g), while the cis-TUFA (48.9g/ 100g) depicted a decrease of 6.1 per
cent. However, in comparison to the fat samples heated at 180ºC, the fat sample used
for frying at 180ºC had a 0.2 per cent lower level of SFA and 14.3 per cent lower
level of TFA, with 2.2 per cent lower levels of cis-TUFA.
When the same fat sample was used for frying at 220ºC (second frying cycle), the
fatty acid composition revealed an increase of 6.3 per cent in SFA (45.7g/ 100g) and
33.3 per cent in TFA (1.60g/ 100g), while cis-TUFA (45.8g/ 100g) reported a
decrease of 6.3 per cent as compared to the first frying cycle at 180ºC.
227
Table 4.II.12: Fatty Acid Profile (including TFA) of Desi ghee(DGM) before and after
subjecting to heating/ re-heating and frying/ re-frying
Treatment Fatty Acid Profile
SFA cis-TUFA TFA
UNHEATED 42.20 52.10 0.68
HEATED AT 180ºC 43.10 50.01 1.40
Change (% Change) 0.90 (2.1%) 2.09 (4.0%) 0.72 (51.4%)
HEATED AT 180ºC 43.10 50.01 1.40
HEATED AT 220ºC 46.10 47.60 1.80
Change (% Change) 3.00 (7.0%) 2.41 (4.8%) 0.40 (22.2%)
HEATED AT 220ºC 46.10 47.60 1.80
Re-HEATED AT 180ºC 48.60 40.30 3.00
Change (% Change) 2.50 (5.4%) 7.30 (15.3%) 1.20 (66.7%)
Re-HEATED AT 180ºC 48.60 40.30 3.00
Re-HEATED AT 220ºC 49.50 38.30 3.30
Change (% Change) 0.90 (1.9%) 2.00 (5.0%) 0.30 (10.0%)
HEATED AT 220ºC 46.10 47.60 1.80
Re-HEATED AT 220ºC 49.50 38.30 3.30
Change (% Change) 3.40 (7.4%) 9.30 (19.5%) 1.50 (83.3%)
UNHEATED 42.20 52.10 0.68
FRIED AT 180ºC 43.01 48.90 1.20
Change (% Change) 0.81 (1.9%) 3.20 (6.1%) 0.52 (76.5%)
FRIED AT 180ºC 43.01 48.90 1.20
FRIED AT 220ºC 45.70 45.80 1.60
Change (% Change) 2.69 (6.3%) 3.10 (6.3%) 0.40 (33.3%)
FRIED AT 220ºC 45.70 45.80 1.60
FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80
Change (% Change) 1.40 (3.1%) 5.76 (12.6%) 1.20 (75.0%)
FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80
FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10
Change (% Change) 1.20 (2.6%) 3.34 (8.3%) 0.30 (10.7%)
FRIED AT 220 ºC 45.70 45.80 1.60
FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10
Change (% Change) 2.60 (5.7%) 9.10 (19.9%) 1.50 (93.8%)
HEATED AT 180ºC 43.10 50.01 1.40
FRIED AT 180ºC 43.01 48.90 1.20
Change (% Change) 0.09 (0.2%) 1.11 (2.2%) 0.20 (14.3%)
HEATED AT 220ºC 46.10 47.60 1.80
FRIED AT 220ºC 45.70 45.80 1.60
Change (% Change) 0.40 (0.9%) 1.80 (3.8%) 0.20 (11.1%)
Re-HEATED AT 180ºC 48.60 40.30 3.00
FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80
Change (% Change) 1.50 (3.1%) 0.26 (0.7%) 0.20 (6.7%)
Re- HEATED AT 220ºC 49.50 38.30 3.30
FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10
Change (% Change) 1.20 (2.4%) 1.60 (4.2%) 0.20 (6.1%)
228
The oil samples used for second frying cycle at 220ºC also showed lower levels of
SFA, TFA as well as cis-TUFA, in comparison to their heated counterparts, depicting
a per cent decrease of 0.9, 3.8 and 11.1 respectively.
When the third frying cycle was carried out in the fat sample subjected to re-heating
at 180ºC (after cooling down to RT), the fat sample demonstrated a per cent increase
of 3.1 in the levels of SFA (47.1g/ 100g) and 75.0 in the levels of TFA (2.80g/ 100g),
while the cis-TUFA levels decreased by 12.6 per cent (40.0g/ 100g) as compared the
fatty acid profile of fat sample used for second frying cycle at 220ºC. In comparison
to re-heating, the fat sample used for frying after subjecting to re-heating at 180ºC,
had lower levels of SFA, cis-TUFA and TFA, pointing to a per cent decrease of 3.1,
0.7 and 6.7 respectively.
Further at the end of the fourth frying cycle carried out in fat sample re-heated up to
220ºC there was an increase of 2.6 per cent in SFA (48.3g/ 100g) and 10.7 per cent in
TFA (3.10g/ 100g) as compared to the third frying cycle at 180ºC in re-heated fat,
while the cis-TUFA (36.7g/ 100g) decreased by 8.3 per cent. Compared to frying at
220ºC, re-using the same fat after subjecting to re-heating at 220ºC (after a cooling
the oil to RT) showed an increase in the SFA by 5.7 per cent, while TFA levels
increased by 93.8 per cent. The cis-TUFA decreased by 19.9 per cent.
On comparing the fatty acid profiles of the re-heated sample of desi ghee at 220ºC and
the desi ghee sample used for frying after subjecting to re-heating at 220ºC, it was
observed that the latter depicted a 2.4 per cent lower levels of SFA, 6.1 per cent lower
level for TFA, while cis-TUFA demonstrated a decrease of 4.2 per cent.
229
Figure 4.II.5: Fatty Acid Profile including TFA for heated/ frying samples of
Refined Groundnut oil
Figure 4.II.6: Fatty Acid Profile including TFA for heated/ frying samples of
Refined Olive oil
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
ROOLP ROOLP
180ºC
HEAT
ROOLP
220ºC
HEAT
ROOLP
180ºC
REHEAT
ROOLP
220ºC
REHEAT
ROOLP
180ºC
FRY
ROOLP
220ºC
FRY
ROOLP
180ºC
REFRY
ROOLP
220ºC
REFRY
g/
10
0g
SFA cis-TUFA TFA
230
Figure 4.II.7: Fatty Acid Profile including TFA for heated/ frying samples of
Refined Soybean oil
Figure 4.II.8: Fatty Acid Profile including TFA for heated/ frying samples of
Refined Canola oil
0
10
20
30
40
50
60
70
80
90
ROC
Unheated
ROC
180ºC
HEAT
ROC
220ºC
HEAT
ROC
180ºC
REHEAT
ROC
220ºC
REHEAT
ROC
180ºC
FRY
ROC
220ºC
FRY
ROC
180ºC
REFRY
ROC
220ºC
REFRY
g/
10
0g
SFA cis- TUFA TFA
231
Figure 4.II.9: Fatty Acid Profile including TFA for heated/ frying samples of
Desi Ghee
Figure 4.II.10: Fatty Acid Profile including TFA for heated/ frying samples of
Partially Hydrogenated Vegetable Oil (Vanaspati)
0
10
20
30
40
50
60
DGM
Unheated
DGM
180ºC
HEAT
DGM
220ºC
HEAT
DGM
180ºC
REHEAT
DGM
220ºC
REHEAT
DGM
180ºC
FRY
DGM
220ºC
FRY
DGM
180ºC
REFRY
DGM
220ºC
REFRY
g/
10
0g
SFA cis-TUFA Tºtal TFA
0.00
10.00
20.00
30.00
40.00
50.00
60.00
PHVºD
Unheatedº
PHVOVD
180ºC
HEAT
PHVOVD
220ºC
HEAT
PHVOVD
180ºC
REHEAT
PHVOVD
220ºC
REHEAT
PHVOVD
180ºC
FRY
PHVOVD
220ºC
FRY
PHVOVD
180ºC
REFRY
PHVOVD
220ºC
REFRY
g/
10
0g
SFA cis-TUFA TFA
232
4.II.2.3 Trans fatty acid in heated/ re-heated fats/ oils under study: The unheated
fats/ oils samples varied in their TFA content, with refined soybean oil, refined
groundnut oil and refined olive oil having undetectable amounts of TFA, while desi
ghee and refined canola oil had 0.68g/ 100g and 1.60g/ 100g of TFA respectively,
however, the TFA levels in partially hydrogenated vegetable oil (PHVOD) were
recorded to be as high as 13.90g/ 100g. When these fats/ oils were subjected to
heating at 180ºC. All the three oils which had undetectable amounts of TFA indicated
formation of TFA, clearly depicting that heating leads to generation of TFA (Table
4.II.13 and Figure 4.II.11). The fats/ oil which already had TFA also showed
increased amounts after being subjected to heat treatment. Edible oils like refined
soybean oil, refined groundnut oil and refined olive oil, depicted a manifold increase,
while refined canola oil and even desi ghee almost doubled in their TFA levels.
However, in partially hydrogenated vegetable oil, although the initial content was
very high but on heating at 180ºC, it showed a mere increase of nearly 9 per cent. This
could be due to already high levels of TFA and SFA imparting the desired stability to
the fat.
When these fats/ oils were heated to a higher temperature, there was further increase
in their TFA levels, with refined soybean oil and refined olive oil depicting more than
100 per cent increase in their TFA levels while refined groundnut oil, refined canola
oil and desi ghee pointing towards an increase of 20-30 per cent. Partially
hydrogenated vegetable oil on the other hand indicated an increase of approximately 6
per cent only. However, on re-heating these fats/ oils at 180ºC again, after cooling
down to room temperature, slight increase in the TFA levels were observed, for
refined groundnut oil (9.5%), refined canola oil (13.8%), refined soybean oil (23.5%),
refined olive oil (23.6%) and partially hydrogenated vegetable oil (11.2%), whereas
the TFA levels of desi ghee increased by more than double (66.7%) as compared to
heating at 220ºC. Further, re-heating these fats/ oils increased the TFA levels in all the
fats/ oils however, the per cent increase varied between 4.5 (partially hydrogenated
vegetable oil) to 236.4 (refined olive oil). This shows the varied nature of the fats/ oil
regarding the formation of TFA. The overall trend however, indicates towards an
increase in formation of TFA on subsequent heating.
233
Table 4.II.13: Trans Fatty Acid Content of Heated and Re-heated Fats/ Oils
Temperature/
Treatment
Refined
Soybean
Oil
(g/100g)
Refined
Groundnut
Oil
(g/100g)
Refined
Olive
Oil
(g/100g)
Refined
Canola
Oil
(g/100g)
Partially
Hydrogenated
Vegetable oil
(g/100g)
Desi
Ghee
(g/100g)
Unheated 0.00 0.00 0.00 1.60 13.90 0.68
180ºC Heat 0.60 1.60 0.42 2.30 15.20 1.40
220ºC Heat 1.70 2.10 0.89 2.90 16.10 1.80
180ºC Re-
Heat 2.10 2.30 1.10 3.30 17.90 3.00
220ºC Re-
Heat 3.70 4.50 3.70 4.20 18.70 3.30
Table 4.II.14: Trans Fatty Acid Content of Fats/ Oil Samples used for Frying/
Re-frying
Temperature/
Treatment
Refined
Soybean
Oil
(g/100g)
Refined
Groundnut
Oil
(g/100g)
Refined
Olive
Oil
(g/100g)
Refined
Canola
Oil
(g/100g)
Partially
Hydrogenated
Vegetable oil
(g/100g)
Desi
Ghee
(g/100g)
Unheated 0.00 0.00 0.00 1.60 13.90 0.68
180ºC Fry 0.36 1.50 0.28 2.09 14.70 1.20
220ºC Fry 1.50 2.01 0.51 2.60 15.80 1.60
180ºC Re-Fry 2.00 2.10 1.40 3.20 17.00 2.80
220ºC Re-Fry 3.20 3.70 3.60 3.90 18.60 3.10
234
Figure 4.II.12Trans Fatty Acid Content of Heated and Re-heated Fats/ Oils
Figure 4.II.13:Trans Fatty Acid Content of fat/ oil samples used for Frying/ Re-
frying
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
Refined
Soybean Oil
Refined
Groundnut Oil
Refined Olive
Oil
Refined
Canola Oil
Desi Ghee Partially
Hydrogeneted
Vegetable Oil
Unheated 180ºC Fry 220ºC Fry 180ºC Re-Fry 220ºC Re-Fry
235
4.II.2.4 Trans fatty acid in the fats/ oils used for frying after subjecting to
heating/ re-heating under the study: In the present study it was observed that
similar to the results of heated fat/ oil samples, there was an increase in the levels of
TFA after each frying cycle in heated/ re-heated fats/ oils. However, in comparison to
the heated/ re-heated fat/ oil samples, the fats/ oils undergoing frying had lesser levels
of TFA. This could have been due to the absorption of the TFA content by the test
food being fried in it. Estimation of TFA in the fried test food could have given a
clearer picture of the entire mechanism however; this could not be undertaken since it
was not in the purview of the study, moreover, the time and resource constraints did
not allow this segment to be aligned in the present study. This segment can definitely
be taken up as independent study in the future.
In a study by Romero et al, (2000) it was suggested that frequent addition of fresh
oil in between the frying cycles minimizes the increment in trans fatty acids.
However, in the present study this aspect was not included as it was outside the scope
of the study.
The formation of TFA during food frying is closely related to the process temperature
and oil use time (Martin et al, 2007). The results of the present study are in line with
study by Moreno et al (1999), who evaluated the effects of temperature and time on
the formation of trans isomers during sunflower oil heating in an open container and it
was observed that trans unsaturations started to increase at 150ºC and became much
more significant from 250ºC onwards. After heating for 20 minutes at 200ºC, 250ºC,
and 300ºC, increasing of 356.5%, 773.9%, and 3026.1%, respectively, in the
concentration of trans isomers in relation to the initial values (0.22 mg/g) were
observed.
The present study depicted an increase in the levels of saturated and Trans fatty acids,
with each episode of heating (with or without the food frying in it) as compared to the
unheated samples (Table 4.II.14 and Figure 4.II.13). While the levels of cis-total
unsaturated fatty acids decreased in all the heated and fried oil samples with respect to
the unheated fat/ oil samples. Several studies have shown deep-fat frying decreases
the content of unsaturated fatty acids in frying fat and oil as compared to unheated oil
samples (Alireza et al, 2010). The per cent increase in the levels of SFA and TFA
continued to increase with each frying cycle with respect to unheated fat/ oil samples.
236
Their percentage continuously increased upon reheating and refrying at same
temperature. Similar trend was noticed in oil samples used for frying/ re-frying with a
slight decrease in TFA concentrations as compared to corresponding heated samples.
The per cent increase in the levels of TFA in the saturate rich fats was less as
compared to high cis-TUFA oils. Although oils with high saturated fatty acids content
show unique stability during frying but are least desirable from a nutritional and
health point of view. In a study by Bansal et al (2009), it was shown that the test oil
samples undergoing frying had more of TFA levels as compared to their heated
counterparts due to the high content of TFA in the test food samples (Pre-frozen
French fries), however, in the present study the test food was free of trans fats as
indicated in the laboratory analysis, thus it is hypothesized that the fried fats/ oils
undergoing frying will have less amount of TFA as compared to their heated
counterparts because the test food fried in these samples was absorbing TFA from the
oil. This can be based on the results of TFA estimation of the pre-fried French fries,
which showed no TFA levels, this was also compared to the nutritional information
given on the nutrition label of the pre-fried frozen French fries as well as the
ingredient list which showed no presence of hydrogenated/ partially hydrogenated
vegetable fat. The laboratory analysis of the fried French fries could have given a
clearer picture, however, it could not be undertaken due to constraint of time and
resource. Overall the study results were able to demonstrate the effect of high
temperature heating/ re-heating of fats/ oil on formation of TFA, which is a common
practice at commercial level.
The results not only showed an increase in the overall percentage of TFA but also in
SFA. This indicates that oil subjected to high temperature heating / re-heating though
have low levels of TFA and that of SFA initially, end up having higher concentrations
of both (TFA and SFA), which is least desired nutritionally. This study was also able
to demonstrate that TFA are also produced during the process of frying, which was
still not clearly established. Further the results of this study can be used to project the
adverse effects of high temperature heating/ re-heating of fats/ oils and plan suitable
strategy in developing and imposing strict guidelines regarding maintaining a specific
temperature of the fat/ oil during frying and changing of oils after a fixed number of
frying cycles as has been done in several western countries.
237
4.II.3 ESTIMATION OF TFA CONTENT IN SELECT FOOD ITEMS (FRIED/
BAKED/ DAIRY FOOD ITEMS)
The consumption of foods high in trans fatty acids have been shown to have adverse
effect on human health. Studies have shown a correlation between trans fatty acid
intake and a change in blood lipid profile as well as a relationship between trans fatty
acids intake and risk of cardiovascular diseases (Bhardwaj et al, 2011b). In addition, it
has also been shown to increase the risk of breast cancer and prostate cancer; insulin
resistance which is a feature of type 2 diabetes; age related macular degeneration
which is a leading cause of visual impairment and blindness in developed countries
and adverse effects on child and maternal health. Experimental and epidemiological
studies have shown strong need of in depth profiling of trans fatty acid levels in
different food and in the human diet, and the factors that lead to alteration in the trans
fatty acid content in oils and fats.
In view of the scarcity of data on the TFA content of Indian food items, in this section
of the present study, an attempt was made to estimate the complete fatty acid profile
including TFA of select fried, baked and dairy food items. On the basis of the
preferences of commonly consumed fried/ baked/ dairy food items indicated by the
subjects in the preliminary questionnaire, a total of 48 food items were identified,
however, due to resource constraint only 23 food items could be analysed for the
estimation of their fatty acid profile including TFA content which included 11 fried
foods, 6 baked foods, 5 dairy food items and 2 samples of mayonnaise (vegetarian and
with egg).
These selected food items were purchased from retail stores or restaurants in Delhi/
NCR and were stored at 4ºC - 6ºC. Prepared foods purchased from restaurants were
analyzed either on the same day or next day (after storing at 4ºC-6ºC) while the
packaged food items were analyzed within three days of the purchase. Where
available, the nutritive value, ingredients, fat sources, batch number, date of
manufacture and other details listed on the package label were recorded (Table
4.II.15).
238
The list of food items analysed for their fatty acid profile including TFA content
includes the following:
Fried Foods:
o Potato chips, Bhujiya, Samosa, Tikki, Bread pakora, Fried Aloo chaat,
Parantha, Bhatura, Gulabjamun, French Fries, Frozen French Fries
Baked Foods:
o Biscuits, Rusks, Patties, Pastry, Pizza, Burger
Dairy Products and other foods:
o Milk, Curds, Cottage cheese, Cream, Cheese Slice and 2 samples of
mayonnaise (vegetarian and with egg).
239
Table 4.II.15: Brand Names and Nutrition Related Information of the Food Samples Selected for Analysis
Food Items Brand/
Shop Code
Batch no/
Lot No. Date of
Mfg/ Pkg Date of
Purchase Date of
Expiry Composition
Nutritional
Information Mark/
Certification
Fried Foods
Potato
Chips Kakaji FFPCK --
19-Jan-
2012 30-Jan-
2012 Best Before
18/Mar/2012 Potato, Edible oil,
Edible salt
per 100g: Energy: 548.6
kcal, Protein: 7.1g, Total
fat: 36.6g, Cholesterol: 0
mg, Carbohydrates; 53
g; TFA:0g,
Vegetarian
Mark
Bhujiya Bikaneri FFBB BICCA 22-Jun-11 2-Jul-2011
Best before
22/12/11.
Store in cool
dry, hygienic
place, protect
the contents
from direct
sunlight
Edible vegetable
oil, Husked dew
gram (41.5%),
Husked gram
(8.5%), Edible
common salt,
spices and
condiments
per 100g: Energy:610.13
kcal, Protein: 13.5g,
Total fat: 46.9g, SFA:
11.9g, PUFA:23.3g,
MUFA: 10.5g, TFA:0g,
Carbohydrate: 33.4g,
Sugar:0g, Fiber:2.3g,
Sodium: 1075.1mg,
Cholesterol:0mg
Vegetarian
Mark
Samosa
Shefali
sweet shop FFSS -- -- 25-Jul-11 -- -- -- --
Bread
Pakora
Roadside
vendor FFBPR -- -- 28-Jul-11 -- -- -- --
Parantha Roadside
vendor FFPR -- -- 2-Aug-11 -- -- -- --
Bhatura
Evergreen FFBhEG -- -- 8-Aug-11 -- -- -- --
Gulabjamun Bikaner FFGJB -- -- 20-Mar-12 -- -- -- --
240
Tikki
Roadside
vendor
FFTRV -- -- 16-Aug-11 -- -- -- --
Fried Aloo
Chaat
Roadside
vendor
FFACRV -- -- 21-Aug-11 -- -- -- --
French
Fries
Bikaner FFFFB -- -- 20-Mar-12 -- -- -- --
Baked Food
Cookies
Rainbows BFCR -- -- 20-Mar-12 -- -- -- --
Patty
Rainbows BFPR -- -- 2-Sep-11 -- -- -- --
Pastry
Shefali BFPS -- -- 8-Sep-11 -- -- -- --
Pizza
Rainbows BFPR -- -- 11-Sep-11 -- -- -- --
Burger
Rainbows BFBR -- -- 19-Sep-11 -- -- -- --
Rusk
MAQ Bread
Toast
BFRL
SA005
Jan-12
20-Mar-12
Best before 6
months from
Packaging
Wheat flour,
sugar, salt, bakery
shortening, milk
powder, semolina,
yeast, baking
powder, added
flavour
Per 100 g: Energy; 420
kcal, CHO; 81.54 g, Fat;
6.60 g, Protein; 8.84g
Vegetarian
Mark
241
Dairy Food
Milk Full
Cream
DMS Milk
DFDMSMFC
221/R-
MMPO/1995
5-Feb-11
5-Feb-11
Use by: 5 Feb
2011, when
stored
refrigerated
below 8 C
Pasteurized full
cream milk
Per 100 ml: fat:6%,
SNF:9.0% Energy:
89kcal, Protein:3.4g,
CHO: 5.1g, Fat:6.2g,
Calcium:150mg
ISO
22000:2005
& ISO
14000:2004
certified
organization
Curds
Mother
Dairy
DFMDC
D10314Ag1-
4 1149
31-Jan-11
2-Feb-11
Best before 10
days from
manufacture
when stored
refrigerated
below 8ºC
Milk, Water, Milk
Solids, and Lactic
acid culture
Per 100 g: Energy: 75
kcal, Protein: 3.7g,
CHO: 5.0g, Fat: 4.5g,
Calcium: 168mg
--
Cream
Amul
DFCRA
GO38
7-Feb-11
5-Mar-11
Best before
120 days from
manufacture
when stored
in a cool and
dry place.
After opening
refrigerate and
use within 4
days
low fat cream
containing Milk
fat 25% minimum.
Per 100 g: Energy: 246
kcal, energy from fat:
225kcal, protein: 2g,
total fat: 25g, SFA: 16g,
Cholesterol: 68mg,
Sodium: 34mg, Total
CHO: 3.2g, Added
sugar: 0.0g, Calcium:
100mg. Not a significant
source of dietary fibre,
vitamin C and iron.
Approx values
242
Cottage
Cheese
Local DFCCL -- -- 20-Mar-12 -- -- -- --
Cheese
Slice
Britannia
DFBCS
Lot no:
JLRA
Dec-10
8-May-11
Best before 9
month of
packaging,
when stored at
4 C under
hygenic
conditions
Cheese, milk
solids, idodised
salt, Emulsifier,
(E331, E 339),
Acidifying agent
(E330, E 260),
preservative (E
200), Colour (E
160a (ii). Contains
permitted colours
Per 100 g: Energy: 309,
Protein: 17.0g, CHO:
4.0g, sugar:0g, Fat:
25.0g, Sodium: 1426mg,
Calcium: 564mg,
Phosphorous: 312mg,
Vitamin A: 416mg
Vegetarian
Mark
243
Other Foods
Vegetarian
Mayonnaise
Fun Foods
MSCFFVM
Lot no: V2-
36606
18-Jan-11
5-Mar-11
Store in a
cool dry
area.
Refrigerate
after
opening. Do
not freeze.
Edible vegetable oil,
water, sugar, milk
solids, lemon juice,
edible common salt,
permitted emulsifying
& stabilising agents
(E1442, E415),
permitted Acids
(E260, E330),
Permitted
Antioxidants (E319).
Contains permitted
class II Preservatives
(E211, E202)
Per 100 g: Energy:
564.7kcal, Protein:
1.2g, Fat: 59.1g,
Trans fats:0.0g,
Cholesterol: 0.0g,
CHO:6.9g, Sugar:
5.4g
Zero
cholesterol,
zero trans
fats, Mfd. In
ISO
22000:2005
certified
plant
Classic
Mayonnaise
Fun Foods
MSCFFCM
V2-378
8-Jan-11
5-Mar-11
Store in a
cool dry
area.
Refrigerate
after
opening. Do
not freeze.
Edible vegetable oil,
water, sugar, egg yolk,
milk solids, lemon
juice, edible common
salt, permitted
emulsifying &
stabilising agents
(E415, E440),
permitted Acids
(E260, E330),
Permitted
Antioxidants (E319).
Contains permitted
class II Preservatives
(E211, E202)
Per 100 g: Energy:
618.1kcal, Protein:
2.4g, Fat: 63.4g,
Trans fats:0.0g,
CHO:9.4g, Sugar:
5.6g
Zero trans
fats, Mfd. In
ISO
22000:2005
certified
plant
244
The fatty acid profile including TFA for all the 23 selected food samples have
been analysed using gas chromatography coupled with flame ionization detectors.
For the assessment of TFA content in food items, fat was extracted from the food
samples using soxhlet method. The individual food items were homogenized/
ground and an accurately weighed representative portion was taken for extraction.
These extracts of fats were then converted into their fatty acid methyl esters
(FAMEs) which were run in a chromatogram to identify the fatty acid (FA) peaks
against those of fatty acid standards.
The fatty acid profile of fried, baked, dairy food items and 2 samples of
mayonnaise (vegetarian and with egg) have been expressed as g/ 100g of the fat
extract. Further, the total amounts of total fat/ fatty acid per 100g of the food item
have also been estimated, from where the TFA content per serving of food item
have also been computed in order to have a clearer understanding and to see the
actual amount of fat, in particular the amount of trans fatty acid being consumed.
Where applicable, accurately measured weights, rounded to nearest whole number
(samosa, bread pakora, aloo tikki, aloo chaat, gulabjamun, bhatura, parantha,
bakery biscuit, rusk, patties, pastry, pizza, burger and cheese slice) or standard
serving sizes (potato chips, bhujia, French fries, milk, curds, cottage cheese,
mayonnaise, mayonnaise with egg) of the selected food samples have been taken
for calculating the values for one serving. The results of fried, baked, dairy food
items are being discussed separately.
4.II.3.1 Laboratory Analysed Fatty Acid Profile of Commercially Prepared
Fried Food Samples Selected for the Study
In all 10 fried food samples were selected for analysis. The complete fatty acid
profile (SFA, cis-MUFA, cis-PUFA, cis-TUFA and total TFA) was estimated for
all the food samples. The results have been expressed as g/ 100g of fat, g/ 100g of
food item and g/ serving of the food item.
The SFA content of these food items (g/ 100g of the extracted fat) ranged between
41.2g (aloo Tikki) to 64.8g (Gulabjamun); cis-MUFA 18.2g (French Fries) to
36.05g (Bhujia); cis-PUFA 10.0g (Gulabjamun) to 19.8g (French Fries) (Table
4.II.16). With respect to the total TFA content of the extracted fat samosa had the
245
highest content (8.1g/ 100g of extracted fat) while bread pakora had the lowest
levels of TFA (2.3g/ 100g of extracted fat). As far as TFA is concerned, there are
a number of factors which could have contributed towards the TFA content of the
food, like the type and quality of fat/ oil used for frying (use of partially
hydrogenated vegetable fat or re-used fat/ oil can lead to higher levels of TFA),
type of food being prepared and duration of frying (foods requiring quick frying
e.g. poori/ bhatura would lead to lesser generation of TFA as compared to food
items like samosa, mathri, bhujiya which require deep frying for longer duration
at varying temperature), duration of heating fat/ oil before frying, temperature at
which frying was done, number of frying cycles, type of fat/ oil used for
shortening in the food etc. Under the prevailing conditions, all these factors are
unknown, thus the TFA content could be due to summation of all these factors.
Table 4.II.16: Laboratory Analysed Fatty Acid Profile of the Fried Foods
Selected for the Study (g/100g of extracted fat)
Food
product Code SFA (g)
cis –
MUFA
(g)
cis –
PUFA
(g)
cis -
TUFA
(g)
Total
TFA
(g)
Potato Chips FFPCK 51.2 26.4 14.6 40.8 3.09
Bhujia FFBB 41.4 36.05 17.7 53.7 3.80
Bread pakora FBPR 48.2 35.7 13.5 49.2 2.30
Tikki FFTRV 41.2 31.4 18.8 50.2 6.10
Aaloo chat FFACRV 43.2 32.6 19.1 51.7 4.70
Samosa FFSS 45.8 30.7 15.5 46.0 8.10
French Fries FFFFB 55.6 18.2 19.8 38.0 6.40
Gulabjamun FFGJB 64.8 21.0 10.0 31.0 3.90
Bhatura FFBhEG 53.2 28.8 14.1 43.0 3.40
Paratha FFPR 43.1 35.02 17.3 52.3 4.70
246
A clearer picture emerged when the fatty acid profile of the selected foods was
expressed per 100g of food item (Table 4.II.17 and Figure 4.II.13); and as g/ per
serving of food item (Table 4.II.18). All these foods, being deep/ shallow fried
had high total fat content ranging between 41.0g/ 100g of food (potato chips) and
10.5g/ 100g of food (gulabjamun). These figures varied when the values were
computed for one serving of food, wherein the total fat content ranged between
7.8g/ serving of bhujiya and 38.0g/ serving of aloo chaat. However, it is to be
noted that one typical serving may vary from individual to individual, as some
people do not even eat one full serving while others consume much more than one
serving.
Bhujia is a commonly consumed tea time snack preferred mostly by
adults, women in particular, while potato chips although are common among
adults particularly office goers, are also the preferred choice of snack among
children and adolescents. Potato chips and bhujia when analysed for their fatty
acid profile including TFA, showed almost similar fatty acid profile per 100 g of
food item, with potato chips having a slightly higher total fat and SFA content
(41.0g and 21.0g) as compared to bhujia (38.9g and 16.1g). The values for cis-
MUFA was higher in bhujia (14.0g) as compared to potato chips (10.8g), while
the cis-PUFA content were almost similar (6.0g and 6.9 g respectively). Their
TFA content also varied slightly, with bhujia having a higher level (1.48g) as
compared to potato chips (1.27g). This could perhaps be due to the longer
duration of cooking required in case of bhujia as compared to potato chips. The
values for one serving of potato chips (35g; 1 small packet) had ≈ 14.4g of total
fat, 7.3g SFA, 3.8 g cis-MUFA, 2.1g cis-PUFA and 0.44g of TFA.
However, these values are bound to increase by double when a large packet (60g)
of chips is consumed. The values for one serving of bhujia has been calculated
for 20g (specified as 1 serving on packet labels) and for 50g (1 small packet,
which is easily consumed at a time). The value of TFA per 20g of serving (0.30g)
was similar to 35g serving of potato chips (0.44g), while that of 50g serving was
0.74g. The TFA content of bhujia as well as potatochips could perhaps be
attributed to the high temperature and duration of heat exposure subjected to the
oil.
247
Bread pakora is a favoured tea time snack specifically among school
teachers (subjects under study) and is easily available in school canteens. The
laboratory analysis of Bread pakora revealed that it had as much as 14.7g of
total fat/ 100g of food item, the value was almost similar (14.0g) when
calculated for one serving (95g). The SFA content per 100g of food was
estimated to be 7.1g, while it was 6.7g in one serving, while the TFA content
in 100g and one serving of bread pakora was 0.34g and 0.32g respectively.
Similar to bread pakora, samosa, is also one of the most common and
frequently consumed, deep fried tea time snack, having fat content equal to
almost three exchanges (15.8g/ 100g of food and 14.2g/ serving of food),
with almost half of it as SFA (7.2g/ 100g of food; 6.5g/ serving). It had
moderate levels of cis-MUFA (4.9g/ 100g of food; 4.4g/ serving) and cis-
PUFA (2.4g/ 100g of food; 2.2.g/ serving). However, the TFA content of
samosa came as a surprise to be as high as 1.28g/ 100g of food and 1.15g/
serving. Indicating that samosa can contribute to a large part of dietary TFA.
Unlike the bread pakora, the fat used for shortening in the crust (which
usually has to be a solid fat like desi ghee or vanaspati to provide appropriate
structure to the crust), sautéing of the filling as well as the temperature and
duration of frying could have together contributed to the TFA content of
samosa.
The fried aloo chaat a very common and popular street food, had
approximately four exchanges of fat per 100g (21.7g/ 100g) with high SFA
(9.4g/ 100g) and moderate levels of cis-MUFA (7.1g/ 100g) and cis-PUFA
(4.1g/ 100g). It had fairly high level of TFA, reaching out to 1.02g/ 100g.
These values increased further when the fatty acid profile was calculated for
one serving (1 plate) of aloo chaat which was 175 gram. Of main concern were
the total fat, SFA and TFA which were found to be reaching far end values of
38.0g, 16.4g and a whopping 1.78g per serving respectively. High TFA content
could possibly be due to the use of partially hydrogenated vegetable fat
(vanaspati) or due to the repeated use of used oil. However, since the food
samples were randomly picked from the market stores, no concrete reasoning
248
can be provided. French fries often referred to as western counterpart of aloo
chaat, and very much liked by the urban Indian population, was also analysed
for its fatty acid profile including total TFA content. The total fat content was
estimated to be almost equivalent to four exchanges of fat (19.9g/ 100g) with
more than half of it coming through SFA (11.1g/100g). Cis-MUFA and cis-
MUFA which were almost equal (3.6g/ 100g and 3.9g/ 100g respectively),
contributed to less than one-fourth of the total fat content. The total TFA
content (1.27g/ 100g) was quite high, similar to that of samosa. However, the
per serving (1 medium French fries; 110g) value of total TFA content was
slightly higher (1.47g/ serving). It was interesting to observe that the value of
total TFA, though was high in 100g French fries as compared to Fried aloo
chaat but the per serving value of total TFA was higher in the latter due to
larger serving size (1 plate;175g).
A similar picture emerged with aloo tikki wherein 100 grams of the food item
had 18.6g of total fat, 7.7g SFA, 5.8g cis-MUFA and 3.5g cis-PUFA. The value
of total TFA was comparable to that of fried aloo chaat, coming to nearly
1.13g/ 100g. The values for per serving (140g; 2 pieces) showed higher levels
of all the fats including total TFA which was 1.59 g. Both aloo tikki and fried
aloo chaat are shallow fried food items, using lot of fat/ oil on griddle (tawa)
and values of high TFA content could be due to the use of vanaspati either
alone or in blend with some other vegetable oil, moreover the fat/ oil being
repeatedly used several times as well as undergoing countless frying cycles
with intermittent episodes of heating and cooling, could further increase the
TFA content.
Gulabjamun on the other hand was detected to have approximately two
exchanges (10.5g) of fat per 100g, which was substantially less in comparison
to all other fried foods, the values slightly increased to less than three fat
exchanges (13.7g) when computed for one serving (2 pcs; 130g). The SFA
content was ≈ 6.8g/ 100g of food item, while cis-MUFA and cis-PUFA were
2.2g/ 100g of food item and 1.1g/ 100g of food item respectively. The total
TFA content was also less in comparison of other fried food items under study
249
(0.41g/ 100g of food item and 0.53g/ serving of food). The values increased
slightly when computed for one serving. However, due to its high sugar content
it cannot be considered as a healthier option. There is paucity of data on TFA
content of Indian sweets, however, the limited data available on the same
reveals that TFA content in Indian sweets (n=8) ranged between 6-28 per cent
of total fatty acids (Ghafoorunissa, 2008), while in the present study it was
noted to be quite low i.e. 3.90g/ 100g of fat extract.
Table 4.II.17: Fatty Acid Profile Fried Foods Selected for the Study
(g/100g food item)
Food product Code Total fat content
(g/ 100g)
SFA
(g/ 100g)
cis – MUFA
(g/ 100g)
cis – PUFA
(g/ 100g)
cis – TUFA
(g/ 100g)
Total
TFA
(g/ 100g)
Potato Chips FFPCK 41.0 21.0 10.8 6.0 16.7 1.27
Bhujia FFBB 38.9 16.1 14.0 6.9 20.9 1.48
Bread pakora FBPR 14.7 7.1 5.2 2.0 7.2 0.34
Tikki FFTRV 18.6 7.7 5.8 3.5 9.3 1.13
Aaloo chat FFACRV 21.7 9.4 7.1 4.1 11.2 1.02
Samosa FFSS 15.8 7.2 4.9 2.4 7.3 1.28
French Fries FFFFB 19.9 11.1 3.6 3.9 7.6 1.27
Gulab Jamun FFGJB 10.5 6.8 2.2 1.1 3.3 0.41
Bhatura FFBhEG 15.4 8.2 4.4 2.2 6.6 0.52
Parantha FFPR 14.9 6.4 5.2 2.6 7.8 0.70
Bhatura, which is a favourite Sunday breakfast dish among the urban north Indian
population consumed at both commercial eating outlets as well as prepared at
home was also analysed for its fatty acid profile. The analysis revealed that it
contains a massive 15.4g fat/ 100g of food with SFA comprising more than half
of it (8.2g). The cis-MUFA and cis-PUFA content were 4.4g and 2.2g/ 100g of
food respectively. The total TFA content which was detected to be 0.52g/ 100g
250
of food, increased remarkably to 1.05g when the values were computed for one
serving (2 pieces; 180g), indicating that even one plate of bhatura (2 pieces) is
sufficient to increase the dietary consumption of TFA.
Parantha which is consumed almost daily by a majority of the urban
population as well as subjects under study when evaluated for its fatty acid
profile revealed high amount of total fat (14.9g), SFA (6.4g) and total TFA
(0.70g) in 100g of food item. The values nearly doubled when computed
for 1 serving (2 pieces; 170g parantha) with TFA content reaching 1.11g/
serving of food item. There was no deep frying involved, even then a
number of factors could have contributed to the TFA content like type of
fat/ oil used for frying and for shortening and the temperature at which
shallow frying was done etc.
Figure 4.II.13: Fatty Acid Profile including TFA of select fried food items
0
5
10
15
20
25
30
35
40
45
g/
10
0g
fo
od
ite
m
Total fat SFA cis - MUFA cis - PUFA Total TFA
251
Table 4.II.18: Fatty Acid Profile Fried Foods Selected for the Study (g/
serving)
Food
product Code
Weight
(serving
size)
Total
fat
content
(g)
SFA
(g)
cis -
MUFA
(g)
cis -
PUFA
(g)
cis -
TUFA
(g)
Total
TFA (g)
Potato
Chips FFPCK
35 g
(1 small
Packet)
14.4 7.3 3.8 2.1 5.9 0.44
Bhujia FFBB 20 g 7.8 3.2 2.8 1.4 4.2 0.30
Bhujia FFBB 50 g(1 small
Packet) 19.5 8.1 7.0 3.4 10.4 0.74
Bread
pakora FBPR
95 g
(1 pc) 14.0 6.7 5.0 1.9 6.9 0.32
Tikki FFTRV 140 g
(2 pcs) 26.0 10.7 8.2 4.9 13.1 1.59
Aaloo chat FFACRV 175 g
(1 plate) 38.0 16.4 12.4 7.3 19.6 1.78
Samosa FFSS 85 g
(1 pc) 14.2 6.5 4.4 2.2 6.5 1.15
French
Fries FFFFB
110 g
(1 Medium
fries)
21.9 12.2 4.0 4.3 8.3 1.40
Gulabjamun FFGJB 130 g
(2 pcs) 13.7 8.8 2.9 1.4 4.2 0.53
Bhatura FFBhEG 180 g
(2 pcs) 30.8 16.4 8.9 4.3 13.2 1.05
Parantha FFPR 170 g
(2 pcs) 25.3 10.9 8.9 4.4 13.2 1.19
252
These results demonstrate that all the fried food items in the study had some
amount of TFA present in them, highlighting that consumption of even one of
these items on a daily basis (as reported in the present study) could significantly
contribute to the total TFA intake and hence the adverse health effects.
4.II.3.2 Laboratory Analysed Fatty Acid Profile of Commercially Prepared
Baked Food Items Selected for the Study
In all 6 bakery food samples were selected for analysis. The complete fatty acid
profile (SFA, cis-MUFA, cis-PUFA, cis-TUFA and TFA) was estimated for all
the food samples. The results have been expressed as gram/ 100gram of fat, gram/
100gram of food item and gram/ serving of food.
Table 4.II.19: Laboratory Analysed Fatty Acid Profile of the Baked Foods
Selected for the Study (g/100g fat)
Food product Code SFA cis -
MUFA
cis -
PUFA
cis -Total
unsaturated
fatty acid
Total
TFA
Bakery
Biscuits BFCR 46.5 36.3 9.2 45.5 5.60
Rusk BFRL 46.3 29.5 21.5 51 2.60
Patties BFPR 43.4 33.2 16.2 49.4 7.02
Pastry BFPS 55.2 24.8 7.8 32.6 6.10
Pizza BFPR 49.1 23.7 20.4 44.2 1.60
Burger BFBR 30.8 35.9 28.7 64.6 3.10
The SFA content in grams/ 100 grams of extracted fat of the selected baked food
samples ranged between 30.8g/ 100g of extracted fat (Burger) and 55.2g/ 100g of
253
extracted fat (Pastry), while the cis-MUFA and cis-PUFA content ranged between
23.7g/ 100g of extracted fat (Pizza) to 36.3g/ 100g of extracted fat (Bakery
Biscuits) and 7.8g/ 100g of extracted fat (Pastry) to 28.7g/ 100g of extracted fat
(Burger) respectively (Table 4.II.19). As far as total TFA content is concerned, it
ranged between 1.6g/ 100g of extracted fat (pizza) to 7.02g/ 100g of extracted fat
(Patties). Baked foods require hardened/ solid fat which can provide some texture
to the food items, the most common choice for this is butter, but owing to its high
cost, cheaper substitute like bakers shortening/ margarine are used. These
substitutes are hydrogenated fats and are thus high TFA content, leading to high
levels of TFA in bakery products. Although, in western countries trans-fat free
bakery fats are available, their availability in India is still a question. A better view
was visible when the fatty acid profile of the selected foods was expressed per
100g of food item (Table 4.II.20 and Figure 4.II.14); and as g/ per serving of food
item (Table 4.II.21).
Bakery biscuits which are quite commonly consumed among Indian households
were detected to have high levels of total fat (23.8g/ 100g of food) and SFA
(11.1g/ 100g of food), with total TFA being as high as 1.33g/ 100g of food. The
values though were high for 100g of food item diluted down to half when
calculated for one serving (2pcs; 50g). However, even then consuming just 2
pieces of bakery biscuits could contribute 0.67g of dietary TFA, mainly coming
from baker’s shortening or margarine (partially hydrogenated vegetable fats).
Consumption of high TFA containing foods can cause adverse health effects in the
longer run. The limited data available in Indian literature on TFA content of
various type of biscuits (n=14) purchased from local bakeries show that TFA
ranged between 30-40 per cent of total fatty acids (Ghafoorunissa, 2008),
however, in the present study it was estimated to be quite low i.e. 5.60g/ 100 g of
extracted fat.
Rusk, which were reported to be commonly consumed by a majority of the
population under study were detected to have nearly two exchanges of total fat
(11.3g), comparatively low levels of SFA (5.2g) and moderate levels of cis-
MUFA (3.3g) and cis-PUFA (2.4g) per 100g. The total TFA content was 0.29g/
254
100g. However, the levels dropped down when the values were computed for per
serving (2pcs- 40g; SFA; 2.1g, cis-MUFA; 1.3g, cis-PUFA; 1.0g and total TFA;
0.12g). It is to be noted that rusk is consumed almost daily by majority of the
subjects as an accompaniment with their morning/ evening tea and therefore even
with low levels of TFA could contribute towards TFA related adverse effects in
the longer run, unless trans fat free fat/ shortening is used.
Patties when tested for their fatty acid profile were found to have as high as
22.5g of total fat per 100g, equivalent to more than four exchanges of fat, with
almost half of it coming from SFA (9.8g/ 100g of food item). The cis-MUFA
and cis-PUFA content were detected to be 7.5g/ 100g of food item and 3.6g/
100g of food item respectively, the total TFA content was also quite high
reaching out to 1.58g/ 100g of food item. The values for per serving (1 pc; 85g)
were quite similar to that of 100g of food item (SFA-8.3g; cis-MUFA- 6.3g;
cis-PUFA; 3.1g; total TFA- 1.34g). Preparation of patties requires substantial
amount of solid fat, although butter is the recommended fat, it is rarely used
owing to its high cost, as a result cheaper fat substitutes like margarine and
baker’s shortening are used which lend desirable texture to the food, however,
these being hydrogenated contribute majorly towards its TFA content.
Pastry, another food item which is quite popular among the masses,
fondly consumed either as part of any celebration (birthday/ anniversary) or
otherwise, when tested for its fatty acid profile including TFA was detected to
have slightly more than three exchanges of total fat (16.4g/ 100g of food item),
mainly coming from SFA (9.1g/ 100g of food item), having comparatively
lesser amount of cis-MUFA (4.1g/ 100g of food item) and cis-PUFA (1.3g/
100g of food item), while total TFA was estimated to be 1.00g/ 100g of food
item. The per serving value calculated for 90g of the food item (1 piece) did not
show a major difference, with total TFA content being 0.90g/ serving of food
item. Although pastry is consumed only at special occasions however,
consuming nearly 0.90g of TFA in one single serving is way too high,
considering the adverse health effects associated with TFA.
255
Pizza, although has an Italian origin, has reached a high level of popularity in
urban India with people of all age groups liking it and reportedly consuming it at
different frequencies. There are different pizza combinations available to suit
individual needs varying in their crusts, texture, thickness, sizes and more
importantly toppings. In the present study a standard vegetarian pizza was
analysed for its fatty acid profile including TFA. The total fat content was
estimated to be ≈13.8g/ 100g of food item, exactly half of which was coming
from SFA (6.8g/ 100g of food item). The cis-MUFA (3.3g/ 100g of food item)
and cis-PUFA (2.8g/ 100g of food item) were almost equal and the total TFA
was estimated to be 0.22g/ 100g of food item. However, the serving size of
pizza varies with each individual, although the standard size is one slice (~70g),
a minimum of two to four pizza slices are consumed on an average. The fatty
acid profile increases with increase in serving size, with respect to total TFA
content the levels range between 0.15 g/ slice to 0.62g/ 4 slices. Although the
levels are much less as compared to other bakery food items, frequent
consumption can still contribute to the overall intake of total TFA.
Burger, another fast food coming from the western cuisine is quite popular
among the urban Indian population. It is available in different combinations and
sizes (with/ without cheese or mayonnaise) to suit individual taste; however, in
the present study a standard vegetarian burger (190g) was taken for assessment
of fatty acid profile including TFA. The total fat content was estimated to be
22.6g/ 100g of food item, ≈ four fat exchanges, while the SFA, cis-MUFA and
cis-PUFA content were 7.0g/ 100g of food item, 8.1g/ 100g of food item and
6.5g/ 100g of food item respectively. The total TFA content was detected at the
level of 0.70g/ 100g of food item. These values almost doubled when computed
for one serving of burger (190g) with total fat coming to be 42.9g and nearly
one-third of it coming from SFA (13.2g), while the total TFA content was as
high as 1.33g. With this high level of TFA provided in a single serving of
burger, frequently consuming it can definitely prove detrimental for the health.
256
Table 4.II.20: Fatty Acid Profile Baked Foods Selected for the Study
(g/100g food item)
Food product Code Total
Fat SFA
cis -
MUFA
cis -
PUFA
cis -
TUFA
Total
TFA
Bakery
Biscuits
BFCR 23.8 11.1 8.6 2.2 10.8 1.33
Rusk
BFRL 11.3 5.2 3.3 2.4 5.8 0.29
Patties
BFPR 22.5 9.8 7.5 3.6 11.1 1.58
Pastry
BFPS 16.4 9.1 4.1 1.3 5.3 1.00
Pizza
BFPR 13.8 6.8 3.3 2.8 6.1 0.22
Burger
BFBR 22.6 7.0 8.1 6.5 14.6 0.70
Figure 4.II.14: Fatty Acid Profile including TFA of select baked food items
0
5
10
15
20
25
Bakery
Biscuits
Rusk Patties Pastry Pizza Burger
g/
10
0g
food
ite
m
Total fat SFA cis - MUFA cis - PUFA Total TFA
257
Table 4.II.21: Fatty Acid Profile Baked Foods Selected for the Study (g/
serving)
Food
product Code
Amount per
Serving
(Serving size)
Total
Fat SFA
cis –
MUFA
cis -
PUFA
cis -
TUF
A
Total
TFA
Bakery
Biscuit BFCR
50 g
(2 pcs) 11.9 5.5 4.3 1.1 5.4 0.67
Rusk BFRL 40 g
(2 pcs) 4.5 2.1 1.3 1.0 2.3 0.12
Patties BFPR 85 g
(1 pc) 19.1 8.3 6.3 3.1 9.4 1.34
Pastry BFPS 90 g
(1 pc) 14.8 8.1 3.7 1.2 4.8 0.90
Pizza BFPR 70 g
(1 slice) 9.7 4.7 2.3 2.0 4.3 0.15
Pizza BFPR
280 g
(1 small
pizza; 4
slices)
38.6 19.0 9.2 7.9 17.1 0.62
Burger BFBR 190 g
(1 pc) 42.9 13.2 15.4 12.3 27.7 1.33
258
4.II.3.3 Laboratory Analysed Fatty Acid Profile of Commercially Available
Dairy Products and Other Food Items Selected for the Study
In all 5 samples of dairy products and 2 samples of mayonnaise (vegetarian and
with egg) were selected for analysis. The complete fatty acid profile (SFA, cis-
MUFA, cis-PUFA and TFA) was estimated for all the food samples. The results
have been expressed as g/ 100g of extracted fat, g/ 100g of food item and g/
serving of food.
The SFA content in g/ 100 g of the total fat of the select dairy products ranged
between 51.7g/ 100 g of the total fat (Full cream milk, curds and cheese slice) to
69.1g/ 100 g of the total fat (Cottage cheese), while the cis-MUFA and cis-PUFA
ranged between 7g/ 100 g of the total fat (Cream) to 34.1g/100 g of the total fat
(Curds) and 9.3g/ 100 g of the total fat (Curds) to 25.3g/ 100 g of the total fat
(cream) respectively (Table 4.II.22).
The total TFA content ranged between 0.79g/ 100 g of the total fat (Curds) to
1.6g/100 g of the total fat (Cheese Slice). Despite the fatty acid profile of both the
samples of mayonnaise (g/100g of extracted fat) being similar, mayonnaise with
egg had a slightly higher level of SFA (48.2g/ 100 g of the total fat) than
vegetarian mayonnaise (44.5g/ 100 g of the total fat). The levels for cis-MUFA
(35.2g/ 100 g of the total fat and 31.2g/ 100 g of the total fat), cis-PUFA (16.8g
and 15.8g) were almost similar for mayonnaise egg and vegetarian mayonnaise
respectively. However, the total TFA content varied with mayonnaise vegetarian
having a lower level (3.3g/ 100 g of the total fat) as compared to mayonnaise egg
(4.7g/ 100 g of the total fat).
A slightly different picture appeared when the fatty acid profile of the selected
foods was expressed per 100g of food item (Table 4.II.23 and Figure 4.II.15); and
as g/ per serving of food item (Table 4.II.24).
259
Table 4.II.22: Laboratory Analysed Fatty Acid Profile of Selected Dairy
Products and Other Food Items (g/100g fat)
Food product Code SFA cis -
MUFA
cis -
PUFA
cis -Total
unsaturated
fatty acid
Total
TFA
Dairy Foods
Milk full
cream DFDMSMFC 51.7 32.6 14.4 47.04 1.10
Curd DFMDC 51.7 34.1 13.2 47.43 0.79
Cottage cheese DFCCL 69.1 20.5 9.3 29.8 1.10
Cream DFCRA 66.5 7 25.3 32.4 1.20
Cheese slice DFBCS 51.7 33.9 12.8 46.7 1.60
Other Foods
Mayonnaise MSCFFVM 44.5 35.2 16.8 52.09 3.30
Mayonnaise
egg MSCFFCM 48.2 31.2 15.8 47.02 4.70
Full cream milk, when analysed for its fatty acid profile including TFA was
detected to have SFA ≈ 3.1g/ 100g of food item, while the values for cis-MUFA
and cis-PUFA were 2.0g/ 100g of food item and 0.9g/ 100g of food item
respectively. The total TFA content was 0.07 (almost negligible). The values
increase to more than double when computed for one serving (1 glass; 240g) with
TFA content ≈ 0.16g/ serving of food item and SFA content being 7.4g/ serving.
The complete fatty acid profile of curd revealed a more or less similar picture
just like milk. The SFA content was 2.3g/ 100g of the food item, while the cis-
MUFA, cis-PUFA and TFA were estimated to be 1.5g/ 100g of food item, 0.6g/
260
100g of food item, and 0.04g/ 100g of food item respectively. The values were
almost similar when computed for one serving of curd (1 katori; 125g).
Cottage cheese (paneer), which is one of the most favoured dairy products
and quite popular among all when assessed for its fatty acid profile revealed
SFA ≈16.2g/ 100g of food item, while the cis-MUFA, cis-PUFA and total TFA
were estimated to be 4.8g/ 100g of food item, 2.2g/ 100g of food item, and
0.26g/ 100g of food item respectively. These values reduced to one-third when
computed for one serving which was taken to be as ≈ 30g (one exchange),
however, the serving size may vary with the type of recipe for which it is used.
Cream, which is an integral part of various recipes including the favourite
dal makhani and fruit cream, when assessed for its fatty acid profile including
total TFA revealed high level of total fat (31.6g/ 100g of food item), majorly
coming through SFA (21.0g/ 100g of food item) and moderately low levels of
cis-MUFA (2.2g/ 100g of food item) as well as cis-PUFA (8.0g/ 100g of food
item). The total TFA content was estimated to be 0.38g/ 100g of food item.
These values however, diluted when computed for per serving which was taken
to be 1 tablespoon (15g).
Cheese slice which is an ingredient of choice (optional) in various food
items including burger, sandwiches, subway sandwiches etc., was also assessed
for its fatty acid profile. The total fat content was detected to be as high as
25.0g/ 100g of food item, with exactly half of it being contributed by SFA
(12.9g/ 100g of food item). The cis-MUFA and cis-PUFA were 8.5g/ 100g of
food item and 3.2g/ 100g of food item respectively. The total TFA was
estimated to be 0.40g/ 100 g of food item, which was highest among all the
dairy products included for laboratory analysis in the present study. However,
the values were much less when computed for one serving which was taken to
be one cheese slice (≈20g).
Apart from the above mentioned five dairy products, this section also includes two
samples of mayonnaise (mayonnaise vegetarian and mayonnaise with egg). These
261
have been included as they form the secret ingredient for burgers, sandwiches, roti
rolls, dips etc. The fatty acid profile of both the mayonnaise differed slightly in
their total fat content and SFA. Vegetarian mayonnaise had slightly lower levels
of total fat and SFA (59.1g/ 100 g of food item and 26.3g/ 100g of food item
respectively) as compared to the classic mayonnaise with egg (63.4g/ 100g of
food item and 30.6g/ 100g of food item respectively), while the cis-MUFA and
cis-PUFA levels were almost equal. The total TFA levels also differed with
vegetarian mayonnaise having 1.95g/ 100g of food item while classic mayonnaise
having 2.98g/ 100g of food item. The value for one serving was computed taking
one tablespoon (15g) as the serving size. The TFA content for one serving was
0.29g in vegetarian mayonnaise while it was 0.45g in mayonnaise with egg.
Table 4.II.23: Fatty Acid Profile of Selected Dairy and Other Food Items (g/
100 g of food item)
Food product Code Total
Fat
(g) SFA
cis -
MUFA cis -
PUFA
cis -Total
unsaturated
fatty acid
Total
TFA
Dairy Foods
Milk full
cream* DFDMSMFC 6.0 3.1 2.0 0.9 2.8 0.07
Curds* DFMDC 4.5 2.3 1.5 0.6 2.1 0.04
Cottage cheese DFCCL 23.4 16.2 4.8 2.2 7.0 0.26
Cream* DFCRA 31.6 21.0 2.2 8.0 10.2 0.38
Cheese Slice DFBCS 25 12.9 8.5 3.2 11.7 0.40
Other Foods
Mayonnaise MSCFFVM 59.1 26.3 20.8 9.9 30.7 1.95
Mayonnaise egg MSCFFCM 63.4 30.6 19.8 10.0 29.8 2.98
*The value of total fat content was taken from the nutrition label of the respective
food item, as they were directly converted to their FAMEs and made to run in GC.
262
Table 4.II.24: Fatty Acid Profile of Selected Dairy and Other Food Items (g/
serving of food item)
Food
product Code
Amount per
Serving (Serving Size)
Total
Fat SFA
cis -
MUFA cis -
PUFA
cis -Total
unsaturated
fatty acid
Total
TFA
Dairy Foods
Milk full
cream*
DFDMSMFC 240 ml (1
glass) 14.4 7.4 4.7 2.1 6.8 0.16
Curd*
DFMDC 125 g (1
Katori) 5.6 2.9 1.9 0.7 2.7 0.04
Cottage
cheese
DFCCL 30 g (1 pc) 7.0 4.9 1.44 0.7 2.1 0.08
Cream*
DFCRA 15 g (1Tbs) 4.7 3.15 0.33 1.2 1.5 0.06
Cheese
Slice
DFBCS 20 g (1 slice) 5.0 2.6 1.7 0.6 2.3 0.08
Other Foods
Mayonnaise
MSCFFVM 15 g (1Tbs) 8.9 3.9 3.1 1.5 4.6 0.29
Mayonnaise
egg
MSCFFCM 15 g (1Tbs) 9.51 4.6 3.0 1.5 4.5 0.45
*The value of total fat content was taken from the nutrition label of the respective
food item, as they were directly converted to their FAMEs and made to run in GC.
263
Figure 4.II.15: Fatty Acid Profile including total TFA of select dairy and
other food items
To minimise the intake of industrial trans fatty acids (I-TFA) some countries have
introduced labelling, while others have introduced legislative limits on the content
of industrial TFA in food. However, most countries still rely on food producers to
voluntarily reduce the industrial TFA content in food. In a study by Stender et al
(2012) to investigate the efficiency of these strategies in the Europe, it was noted
that the TFA content in three different products (biscuits, cakes and wafers)
bought in the six European countries in 2005 and 2009 were compared. The
highest industrial TFA contents (10-15 g) in 100 g of food item in 2005 were
found in Hungary, Poland and the Czech Republic (Eastern European countries).
In France, Germany and the United Kingdom (Western European countries), the
industrial TFA contents were lower but still with many above 2 g in 100 g of food
item. In 2009, even after biscuits, cakes and wafers in the three Eastern European
countries contained a smaller, but still substantial, amount of industrial TFA. In
contrast, the industrial TFA content in food items in the three Western European
countries was minimal (<1 g/ 100g of food item).
0
10
20
30
40
50
60
70
Milk full
cream
Curd Cottage
cheese
Cream Cheese Slice Mayonnaise
vegetarian
Mayonnaise
with egg
g/
10
0g
of
foo
d ite
m
Total fat SFA cis - MUFA cis - PUFA Total TFA
264
In the present study twenty three food samples were analyzed using gas
chromatography (GC) coupled with flame ionization detectors (FID) for their fatty
acid profile including total TFA. A substantial number of products particularly the
fried and baked food items, contained a total amount of trans fatty acid that was
much higher than the tolerable limit of 2% of total fats enforced in Denmark, the
only country in the world that has a legal limit for trans fatty acids. Hence, the
public health authorities in India should initiate the legal process to introduce a
trans fatty acid limit for Indian foods in order to reduce the incidence of non-
communicable diseases.
4.III COMPOSITE USE OF THE DATA FROM LABORATORY
ANALYSIS AND FIELD WORK
As discussed earlier, in the present study the preliminary field work data formed
the basis for laboratory analysis and the study results of the laboratory analysis
were used for calculating the dietary intake, particularly the dietary intake of trans
fatty acids.
4.III.1 Dietary Intake with Special reference to Trans fatty Acid
In the present study the dietary intake of the subjects was assessed by a two day
(one working and one non-working day) 24-hour dietary recall method
(Table.4.III.1). The per cent energy derived from protein, carbohydrates, total fat
and fatty acids (SFA, cis-MUFA, cis-PUFA, omega 3 fatty acids, omega 6 fatty
acid and total TFA) were also calculated for all the subjects. As already discussed,
nearly half of the subjects (53.0%) were vegetarians and majority of them were
consuming three main meals. The pattern of consumption of mid-meals/ snacks
revealed that ~50 per cent of the subjects were having two mid-meals/ snacks per
day (early morning tea and evening tea). The frequency of consuming outside
food varied from daily to once a month with almost one-fourth of the subjects
reportedly consuming outside food almost thrice a week. The nutrient profile of
the Indian population is distinctive and highly heterogeneous in its composition
and varied in intake. While there is a general preponderance of vegetarianism, as
is evident in the present study, variations in the carbohydrate, fat and fiber
intakelargely depend upon the geographical region and socio-demographic profile
of the individual.
265
Energy: Data indicate that the average energy intake among the study
population was 2135 ± 254 kcal/ d. the mean intake on the non-school day (2219
± 391 kcal/ d) was significantly higher (p<0.001) than that on the school day
(2052 ± 281 kcal/ d). Elaborate meals, specifically breakfasts (mostly including
parantha/ poori or pakora) coupled with eating out on weekends (non-working
day) could perhaps be the most probable reason for the increased calorie
consumption. Changes in dietary habits have been involved in increasing the
burden and vulnerability of Indians to CVD (Rastogi et al, 2004).
Protein: The average protein intake by the subjects was 61.9 ± 8.9 g/d.
Just like energy, protein intake was also significantly higher (p <0.001) on non-
working day (65.3 ± 13.1 g/d) as compared to the working day (58.4 ± 11.5 g/d).
Further, the average per cent energy derived from protein was 11.6 ± 0.8. It was
almost similar for working and non working days (11.4 ± 1.4% and 11.8 ± 0.8%
respectively). In the present study, most of the subjects were vegetarian thus
pulses and dairy products were the only major proteins sources.
Carbohydrate: Carbohydrates form a major source of energy, especially
in the typical Indian cereal-based diets. In the present study, the average
carbohydrate intake among the subjects was 304.2 ± 40.0 g/d. It was significantly
higher (p <0.001) on non-working day (316.7 ± 56.5 g/ day) as compared to
working day (291.7 ± 55.5 g/d). The average per cent energy derived from
carbohydrates was found to be ~ 57 per cent. The mean energy per cent of
carbohydrates for working day was 56.9 ± 7.7, while that for non-working day
was slightly higher (57.1 ± 4.0). A high intake of refined carbohydrate may lead
to hyperinsulinaemia, high serum TG, low HDL-c levels and is also associated
with insulin resistance. The consumption of large carbohydrate meals is very
common in Asian Indians, especially at dinner time. This permits
hyperinsulinaemia to occur, and also causes postprandial hyperglycaemia and
hypertriglyceridemia. Therefore, a rational strategy would be to distribute
carbohydrate evenly throughout the day, through three to five meals per/ d,
especially in patients with diabetes, so as to avoid high carbohydrate loading.
266
Total Dietary Fibre delays the intestinal transit of the food consumed, is
important for proper bowel function and to reduce occurrence of chronic
constipation, diverticular disease and haemorrhoids. It also helps to reduce
plasma cholesterol and has a protective role against colon cancer, coronary
heart diseases, diabetes and obesity. In the present study the average intake of
total dietary fibre was 41.45 ± 7.0g/d. The intake was lower on working day
(39.4 ± 10.9 g/ d) as compared to the non-working day (43.5 ± 9.0 g/d; p
<0.001). Evidence from epidemiological studies supports the beneficial effects
of high intakes of fruits and vegetables, with possible reductions of over 80
per cent in CHD, 70 per cent in stroke and 90 per cent in T2DM by following
Mediterranean diets, which are low in energy and high in fibre (Willett, 2006).
Total Fat: Since the 1930s, several studies have implicated high dietary
fat intake with the development of obesity and hyperglycaemia (Cornish et al,
2006). A high dietary intake of fat has been reported in Asian Indians (Misra
et al, 2009a). Fat consumption ranged from 13 to 59 g/d in different regions
and states in India. In the present study the mean total fat intake was 75.7 ±
13.1 g/d. The consumption was more on the non-working day (80.9 ± 17.2
g/d) as compared to the working day (72.1 ± 17.4 g/ d; p <0.001). Similarly,
the per cent energy derived from fats was lower on working day (31.6 ± 6.7)
as compared to non-working days (32.8 ± 3.7; p <0.001), with the average
being 32.2 ± 4.2 per cent, which is slightly higher than the recommendation of
30 per cent of energy derived from fats.
Saturated fatty Acid (SFA): Dietary saturated fat intake has been shown
to increase low-density lipoprotein (LDL) cholesterol, and therefore has been
associated with increased risk of cardiovascular diseases (Siri-Tarino, 2010).
This evidence, coupled with inferences from epidemiologic studies and clinical
trials, has led to longstanding public health recommendations for limiting
saturated fat intake as a means of preventing CVD. In the present study the
mean SFA intake was 27.4 ± 6.8 g/ d. The intake was more on the non-working
day (29.6 ± 8.7g/ d) as compared to the working day (25.2 ± 8.9g/ d; p <0.001).
Similarly, the per cent energy derived from saturated fats was higher on non-
267
working day (12.0 ± 2.2; p <0.05) as compared to the working day (11.1 ± 3.5),
with the average being 11.5 ± 2.1 per cent, which is higher than the
recommendation of 10 per cent energy coming from saturated fats. Higher SFA
intake has also been reported to be associated with worse global cognitive and
verbal memory trajectories (decline), whereas higher MUFA intake was related
to better trajectories (Okereke et al, 2012).
Mono Unsaturated fatty Acid (MUFA): Studies have shown that a
MUFA-enriched diet results in significant increases in insulin sensitivity with
modest total fat intake in healthy subjects (Vessby et al, 2001). Further, MUFA-
rich diets have reported to lower mean plasma glucose and plasma TG levels and
reduced insulin requirements in patients with T2DM. The increase in insulin
sensitivity induced by MUFA-rich diets may be due to their effect on gastric
emptying and increased basal glucose uptake (Garg, 1998). Overall, high-MUFA
diets have shown beneficial effects in T2DM, but their influence on insulin
resistance, although appearing beneficial, is still inconclusive. The MUFAs are
present in olive, mustard, almond, canola, groundnut etc. The mean MUFA
intake in the present study was 20.2 ± 4.6g/ d. As in case of total fat and SFA the
consumption was more on the non-working day (21.3 ± 5.5g/ d) as compared to
the working day (19.1 ± 6.9g/ d; p <0.05). However, the per cent energy derived
from fats was almost similar for working day (8.4 ± 2.8) as well as non-working
days (8.7 ± 1.5), with the average being 8.5 ± 1.6 per cent, which is lower than
the recommended 10-15 per cent energy to be derived from monounsaturated
fats.
Poly Unsaturated fatty Acid (PUFA): The polyunsaturated fatty acids
(PUFA), primarily linoleic acid (LA) (n-6) and alpha-linolenic acid (ALA) (n-3),
have structural and functional roles in all cells and are essential dietary
components (Misra et al, 2010). The data on the intake of PUFA ranged from 3.3
per cent (India) to 11.3 per cent (Taiwan), and varied between 4 per cent and 6 per
cent in other developing countries. In the present study the mean PUFA intake
was 22.3 ± 3.0 g/ d. The consumption was more on the non-working day (23.4 ±
3.3g/ d) as compared to the working day (21.2 ± 4.5g/ d; p<0.05). The per cent
268
energy derived from polyunsaturated fats was almost similar for working (9.3 ±
2.0) as well as non-working days (9.5 ± 1.1), with the average being 9.4 ± 1.11 per
cent.
Total Trans fatty Acid (TFA): TFA are known to increase LDL-c levels,
worsen insulin resistance, may influence systemic inflammation, adiposity and
contribute to the development of T2DM and CHD (Laake et al, 2012). Besides
these effects, trans fatty acids may also elevate levels of lipoprotein(a)
(Mozaffarian, 2006). This fact is critically important in Indians where one of the
highest levels of lipoprotein(a) has been recorded and correlated to CHD (Anand
et al, 1998). Till date trans fatty acids in Indian diets were thought to be derived
only from vanaspati, which is used as cooking medium in India with TFA
content as high as 53 per cent. However, the present study indicates that even
refined vegetable oils which were initially considered free of trans fats contain
TFA after heating/ re-heating at high temperatures. With widespread and
increasing use of vanaspati, intake of trans fatty acid is likely to increase further
in the Asian Indian population. This issue is of further concern, since trans fatty
acids adversely alter the uptake and metabolism of essential fatty acids to an
extent that their deficiency may manifest (Hill et al, 1979). This is particularly
true if the essential fatty acid intake is low, as in the sample of Asian Indians
studied by Misra et al (2001).
In developing countries, the major contribution (> 4 en %) to dietary TFA is due
to consumption of industrially produced deep-fried and baked foods (Khosla and
Hayes, 1996; Misra et al, 2010). The estimates of trans fatty acid intake in
developed countries range from 0.5 to 2.6% of energy (Lichtenstein, 2000). In a
study by Misra et al (2001) in urban slum population of North India, the
consumption of TFA particularly in men was greater than 1 en %, while in
women it was 0.75 en%. Further, TFA intake (en %) was 1.1 en%
amongadolescents and young adults in North India (Misra et al, 2009a).
In the present study, the mean total trans fatty acid intake was 4.91 ± 1.5g/ d.
The consumption was noted to be much higher on the non-working day (5.93 ±
1.9g/ d) as compared to the working day (3.89 ± 1.1g/ d). Similarly, the per cent
269
energy derived from total trans fats was much higher on non-working day (2.40
± 1.51) as compared to working days (1.71 ± 0.64), with the average being 2.06
± 0.58 per cent, which is much higher than the dietary recommendation by
WHO (< 1 per cent energy derived from total trans fats). The average intake of
TFA in the present study is comparable to the average intake by the US
population, where in consumption of approximately 5.3 g TFA per day (2.6% of
their total energy intake) has been reported (Castro et al, 2010). Studies have
suggested that an intake of above 5 g of TFA daily is associated with health risk
that can be eliminated more easily than many other diet-associated health risks
by reducing TFA intake (Stender et al, 2012).
ω-3 Fatty Acid: Evidence from experimental studies has indicated the beneficial
effect of long-chain n-3 PUFA (fish oils) over n-6 PUFA (safflower-seed oil) in
preventing insulin resistance (Giacco et al, 2007). The mean ω- 3 fatty acid
intake in the present study was 2.3 ± 0.9 g/ d. The consumption was almost
similar on working (2.1 ± 1.5g/d) and non-working day (2.4 ± 0.8g/ d). The
average per cent energy derived from ω- 3 fatty acid was 0.94 ± 0.4, with the
consumption being almost similar on both working and non-working day (0.92 ±
0.6 vs 0.97 ± 0.3), which is much less than the recommendation of 1-2 per cent
energy to be derived from ω- 3 fatty acid.
ω-6 Fatty Acid: The mean ω- 6 fatty acid intake was 19.3 ± 2.7g/ d. The
consumption was higher on non-working (20.1 ± 4.2g/d) than the working day
(18.4 ± 2.6g/d; p<0.05). However, the per cent energy derived from ω- 6 fatty
acid was similar for working (8.07 ± 1.9) and on non-working day (8.15 ± 0.8),
with the average being 8.11 ± 1.0 per cent, which is within the recommended
range of 5-8 per cent energy to be derived from ω- 6 fatty acid. The mean ω-6/
ω-3 ratio was 8.6 ± 1.7, which was almost similar for both working (8.8 ± 1.9)
and the non-working day (8.4 ± 2.6), which is within the recommended range of
5-10.
Dietary Cholesterol:Dietary cholesterol is present only in foods of animal origin
such as milk, meatand their products, but not in plant foods. Vegetable oils do not
contain cholesterol. Cholesterol is found in all body cells and plays a key role in
270
the formation of brain, nerve tissue and is a pre-cursor for some hormones and
vitamin D. It is synthesized in the body and hence it is not an essential dietary
component. High cholesterol consumption has been associated with cardio-
metabolic risk factors. The blood cholesterol-elevating effect of dietary saturated
fats increases, when cholesterol consumption is high. Therefore, cholesterol
intake should be maintained below 200 mg/day. In the present study the mean
cholesterol consumption was 106.0 ± 26.0 mg/ d. The consumption was
significantly much higher on non-working day as compared to the working day
(p<0.001).
The present study depicted higher consumption of most of the nutrients on non-
working days as compared to working days which as discussed earlier could
possibly be due to elaborate, fat rich meals along with the increase in eating out
trend in the urban population.
271
Table 4.III.1: Average Nutrient Intake by the Subjects on Working and Non-
working Days (N=402)
Nutrients
Working
(School) Day
Non-Working
(Non- School)
day p value
Average
Mean ± SD Mean ± SD Mean ± SD
Energy (kcal) 2051.7 ± 281.3 2219.3 ± 390.7 <0.001 2135.5 ± 254.3
Protein (g) 58.4 ± 11.5 65.3 ± 13.1 <0.001 61.9 ± 8.9
Protein en% 11.4 ± 1.4 11.8 ± 0.8 0.984 11.6 ± 0.8
Carbohydrate (g) 291.7 ± 55.5 316.7 ± 56.5 <0.001 304.2 ± 40.0
Carbohydrate en% 56.9 ± 7.7 57. 1 ± 4.0 0.867 57.0 ± 4.2
Total Fat (g) 72.1 ± 17.4 80.9 ± 17.2 <0.001 75.7 ± 13.1
Fat en% 31.6 ± 6.7 32.8 ± 3.7 <0.001 32.2 ± 4.2
SFA (g) 25.2 ± 8.9 29.6 ± 8.7 <0.001 27.4 ± 6.8
SFA en% 11.1 ± 3.5 12.0 ± 2.2 <0.05 11.5 ± 2.1
MUFA (g) 19.1 ± 6.9 21.3 ± 5.5 <0.05 20.2 ± 4.6
MUFA en% 8.4 ± 2.8 8.7 ± 1.5 0.086 8.5 ± 1.6
PUFA (g) 21.2 ± 4.5 23.4 ± 3.3 <0.05 22.3 ± 3.0
PUFA en% 9.3 ± 2.0 9.5 ± 1.1 0.995 9.4 ± 1.1
TFA (g) 3.89 ± 1.1 5.93 ± 1.9 <0.001 4.91 ± 1.5
TFA en% 1.71 ± 0.64 2.40 ± 1.51 <0.001 2.06 ± 0.58
ω 3 (g) 2.1 ± 1.5 2.4 ± 0.8 0.892 2.3 ± 0.9
ω 3 en% 0.92 ± 0.6 0.97 ± 0.3 0.781 0.94 ± 0.4
ω 6 (g) 18.4 ± 2.6 20.1 ± 4.2 <0.05 19.3 ± 2.7
ω 6 en% 8.07 ± 1.9 8.15 ± 0.8 0.992 8.11 ± 1.0
Cholesterol (mg) 97.4 ± 35.4 114.5 ± 34.0 <0.001 106.0 ± 26.0
Total Dietary Fiber
(g) 39.4 ± 10.9 43.5 ± 9.0 <0.001 41.45 ± 7.0
n6/n3 ratio 8.8 ± 1.9 8.4 ± 2.6 0.981 8.6 ± 1.7
272
4.III.2Anthropometric measurement The data on anthropometric measurements and body composition gathered for this
study included height, weight, waist circumference, hip circumference, body fat
percentage, fat mass, fat free mass, muscle mass,bone mass [as assessed using bio
impedance analysis (BIA) body composition analyser] and calculation of body
mass index (BMI) and waist hip ratio (WHR). The mean height of the subjects
was 156.6 ± 6.2 cm, ranging between 140 cm to 178 cm, while mean weight of the
subjects was 64.6 ± 9.4 kg, ranging between 41 to 101.5 kg. The mean BMI value
of the subjects was 26.4 ± 4.1 kg/m2 ranging from 15.8 to 44.5 kg/m
2. The mean
value for waist circumference, hip circumference and waist hip ratio was 89.0 ±
11.6 cm (range; 58 to 126 cm), 97.4 ± 10.0 cm (ranged from 74 to 137 cm) and
0.92 ± 0.8 (0.69 to 1.2) respectively. The mean body fat percentage was noted to
be 35.7 ± 9.84 % (ranging from 12.6% to 72.9%), while the mean value for fat
mass was found to be 28.1 ± 11.2 kg (ranging between 7.2 to 71.1kg). The mean
fat free mass, muscle mass and bone mass were 37.6 ± 9.0 kg, 37.8 ± 5.9 kg and
2.6 ± 1.9 kg respectively (Table 4.III.2).
Table 4.III.2 Anthropometric Measurements
Anthropometric Measurements Mean ± SD Range
Height (cm) 156.6 ± 6.2 140 - 178
Weight (kg) 64.6 ± 9.4 41 - 101.5
BMI (kg/m2) 26.4 ± 4.1 15.8 - 44.5
Waist Circumference (cm) 89.0 ± 11.6 58 – 126
Hip Circumference (cm) 97.4 ± 10.0 74 – 137
Waist Hip Ratio 0.92 ± 0.8 0.69 - 1.2
Body Fat (%) 35.7 ± 9.84 12.6 - 72.9
Fat Mass (kg) 28.1 ± 11.2 7.2 - 71.1
Fat Free Mass (kg) 37.6 ± 9.0 12.6 - 58.4
Muscle Mass (kg) 37.8 ± 5.9 12.4 - 55.4
Bone Mass (kg) 2.6 ± 1.9 1.2 - 3.4
Prevalence of obesity: Obesity has emerged as an important health problem
worldwide including the developing countries like India. Obesity, abdominal
obesity, and co-morbidities are increasingly prevalent among urban Indians (Misra
et al, 2009b). In the present study the prevalence of overweight and obesity on the
273
basis of BMI alone was 21.9 per cent (BMI ≥ 23 - < 25) and 56.0 per cent (BMI ≥
25) respectively. The prevalence of obesity in the present study was higher than
the prevalence reported by Bhardwaj et al (2011b) among 242 women (50.1%)
residing in New Delhi, as well as the prevalence of 45.9% reported in an urban
population of Chennai in South India (Deepa et al, 2007).
Apart from weight, regional fat distribution, particularly abdominal obesity, is
considered important for development of insulin resistance, the metabolic
syndrome and coronary heart disease (Bhardwaj et al 2011b). In the present study
prevalence of obesity according to waist circumference was 75.6 per cent (WC >
80 cm) which was higher to the obesity prevalence calculated by BMI (Table 4.
III.3). The prevalence on the basis of waist hip ratio was recorded as 71.9 per cent
(WHR ≥ 0.8). More than 80% of total body fat is distributed in the subcutaneous
adipose tissue (SCAT) and 10-20% within visceral/ intra-abdominal adipose tissue
(IAAT) in adults (Wang et al, 2005). The prevalence of obesity on the basis of per
cent body fat per cent came around 70.7 per cent (body fat% ≥ 30%). Asian
Indians exhibit unique features of obesity; excess body fat, abdominal adiposity,
increased SCAT, IAAT and deposition of fat in ectopic sites (liver, muscle etc),
that may be responsible for high tendency to develop insulin resistance and
dysmetabolic state (Misra et al, 2009b). This high prevalence of generalized
obesity (by measurement of BMI and per cent body fat) and abdominal obesity
(by measurement of WC) and dysmetabolic state in urban Indian women is a
cause for serious concern and need urgent public health intervention.
Table 4.III.3: Prevalence of Obesity in the Study Population (N=402)
Prevalence of Overweight and Obesity N (%)
BMI ≥ 23 - <25 kg/m2 88 (21.9)
BMI ≥ 25 kg/m2 225 (56.0)
WC > 80 cm 304 (75.6)
WHR ≥ 0.80 289 (71.9)
Body fat % ≥ 30 per cent 284 (70.7)
274
Figure 4.III.1: Prevalence of overweight, obesity and hypertension in the
study population (N=402)
4.III.3. Clinical Parameters
In the present study, data were gathered on pulse rate and blood pressure, in
addition self-reported data on family history of obesity, diabetes, hypertension and
heart disease were also gathered.
Pulse Rate: Pulse rate/ heart rate refers to the number of heart beats per
unit of time, typically expressed as beats per minute (bpm). It can vary as the
body's need to absorb oxygen and excrete carbon dioxide changes, such as during
exercise or sleep. The measurement of heart rate is used by medical professionals
to assist in the diagnosis and tracking of medical conditions. The average pulse
rate of the subjects was 78.6 ± 9.4 beats per minute, ranging between 60 bpm to
106 bpm (Table 4. III.4).
Blood pressure: The mean ± SD systolic and diastolic blood pressure was
127.7 ± 20.4 and 77.9 ± 17.9 ranging between 93 to 185 mmHg and 52 to 145
0
10
20
30
40
50
60
70
80
Overweight
(BMI ≥ 23 -
<25 kg/m2)
Obesity (BMI
≥ 25 kg/m2)
WC > 80 cm WHR ≥ 0.80 Body Fat %
(≥ 30 per cent)
Hypertension
(NCEP ATP
III)
Hypertension
(JNC VII )
21.9
56
75.6
71.9 70.7
37.8 36.1
Per c
en
t
275
mmHg respectively. The prevalence of hypertension was 36.1 per cent according
to the JNC VII criteria (SBP ≥ 140 and DBP ≥ 90 mmHg), while it was 37.8 per
cent according to the NCEP ATP III criteria (SBP ≥ 130 and DBP ≤ 85 mmHg)
respectively (Misra et al, 2009) JAPI. The prevalence of hypertension according
to the JNC VII criteria (36.1 per cent) in the present study is similar to the
prevalence (39.2%) among 35-70 year old Indian women (both urban and rural) in
a population based nationwide study by Gupta et al (2012). According to the
study significant determinants of hypertension include age, high dietary fat, low
fiber intake, truncal and generalized obesity and even urban residence (Gupta et
al, 2012). While in another study by Bhardwaj et al (2011b) the prevalence of
hypertension among 242 women staying in New Delhi was found to be 25.2%.
Table 4.III.4 Clinical Parameters and Prevalence of Hypertension among the
Study Subjects
Clinical Parameters Mean ± SD Range
Pulse Rate (bpm) 78.6 ± 9.4 60 – 106
Systolic Blood Pressure (mmHg) 127.7 ± 20.4 93 – 185
Diastolic Blood Pressure (mmHg) 77.9 ± 17.9 52 – 145
Prevalence of Hypertension N %
NCEP ATP III ≥ 130/ ≥ 85 mmHg 192 37.8
JNC VII guidelines ≥ 140/ ≥ 90 mmHg 152 36.1
- Family History: Data were also gathered from subjects regarding their family
history of diseases like heart disease, hypertension, diabetes and obesity. Family
history for any disease forms an important basis for assessing the future risk of
developing that particular disease in an individual. In the present study 37.8 per
cent subjects reported a positive family history of obesity, while 29.6 per cent
reported a family history of hypertension (Table 4. III.5). Family history of heart
disease was positive for more than half of the subjects (~52%) while that for
276
diabetes was positive for nearly one-fourth (24.6%) subjects. Studies have
shown that there is a strong positive relationship between a potent parental family
history of a particular disease and development of that disease in the offspring. In
view of the current results, which show a strong family history for all the
mentioned metabolic abnormalities it is important that the study subjects adapt to
a healthy lifestyle and work towards its prevention.
Table 4.III.5: Self Reported Data on Family History of Heart Disease,
Diabetes, Hypertension and Obesity among Subjects
Family History N (%)
Family history of Heart Disease 209 (52.0)
Family history of Hypertension 119 (29.6)
Family history of Diabetes 99 (24.6)
Family history of Obesity 152 (37.8)
4.III.4Biochemical Parameters
The present study included assessment of biochemical parameters like fasting
blood glucose, fasting serum insulin and complete lipid profile (total cholesterol,
serum triglycerides, low density lipoprotein cholesterol, high density lipoprotein
cholesterol and very low density lipoprotein cholesterol) in a sub sample of the
population (n=162). For the biochemical parameters, it was proposed to collect the
blood samples from one-third of the enrolled subjects (n=135) from 2 schools,
however, the targeted number could not be achieved, therefore one more school
(from the 6 schools selected) was approached for blood parameters. Thus, the final
sample for blood estimation is 162 subjects. Once the teacher expressed her
interest in participation in the study and provided written consent, the preliminary
survey questionnaire cum interview schedule was administered followed by
collection of blood samples.
The mean ± SD fasting blood glucose was 99.8 ± 24.1 mg/ dL, ranging from 52 to
181 mg/ dL (Table 4.). The mean ± SD fasting serum insulin level was 11.1 ± 6.6
μU/ mL, while the mean HOMA- IR level was 3.4 ± 2.2. The mean levels for total
277
cholesterol and serum triglycerides were 198.8 ± 46.5 and 147.5 ± 47.4
respectively. Subjects’ mean levels for LDL-c, HDL-c and VLDL-c were 98.7 ±
38.4 mg/dL, 46.6 ± 9.8 and 29.8 ± 10.5 respectively (Table 4.III.6).
Table 4.III.6: Biochemical Parameters of the Subjects under Study (n=162)
Biochemical Parameters Mean ± SD Range
Fasting Blood Glucose (mg/ dL) 99.8 ± 24.1 52.0 - 181.0
Fasting Serum Insulin (μU/mL) 11.1 ± 6.6 6.1 - 43.5
HOMA-IR 3.4 ± 2.2 0.9 - 12.6
Fasting Lipid Profile
Total Cholesterol 198.8 ± 46.5 104.0 - 293.7
Serum Triglyceride 147.5 ± 47.4 62.3 - 339.5
Low Density Lipoprotein Cholesterol 98.7 ± 38.4 43.8 - 203.8
High Density Lipoprotein Cholesterol 46.6 ± 9.8 20.2 - 68.9
Very Low Density Lipoprotein
Cholesterol 29.8 ± 10.5 12.5 - 67.9
Cardio-metabolic risk factors
In the present study an attempt was made to study the cardio-metabolic risk
factors like impaired fasting glucose, diabetes, hyperinsulinimia,
hypercholesterolemia, hypertriglyceridimia, high LDL-c levels, low HDL-c levels
and the metabolic syndrome in a sub sample of the population under study
(n=162). Although the sample size was small but it gave a sufficient idea of the
metabolic state in the study population. Around one-fourth of the subjects had
impaired fasting glucose (IFG; 24.7%) while almost 18.5 per cent of the subjects
were suffering from diabetes (Table 4.III.7). Asian Indians, as an ethnic group,
have an unusually high predisposition to develop type 2 diabetes mellitus (T2DM)
and CVD. During the previous three decades, the prevalence of T2DM has almost
278
doubled in India and currently there are an estimated 62.4 million people with
diabetes and 77.2 million with pre-diabetes in India (Anjana et al, 2011).
Insulin resistance refers to a state in which a given concentration of insulin
produces a less-than-expected biological effect. It is a forerunner of T2DM and
cardiovascular disease (CVD) (Bonora et al, 2002). In the present study the
prevalence of hyperinsulinimia (fasting serum insulin ≥ 10.4 μU/mL) was reported
in as high as 45.7 per cent subjects, while insulin resistance as detected by
HOMA-IR (HOMA-IR ≥ 2.29) was present in 51.9 per cent subjects. Insulin
resistance and clustering of other metabolic risk factors, seen frequently in Asian
Indians, may be principal contributory factors for high prevalence of T2DM (Goel
et al, 2009).
The prevalence of hypercholesterolemia was seen in 43.8 per cent subjects while
that of hypertriglyceridemia was 44.4 per cent. Nearly 59.9 per cent of the
subjects had high levels of LDL-c (≥ 100mg/dL) which was higher than that of
42.7 per cent reported among women in urban population of New Delhi
(Bhardwaj et al, 2011b). Of specific concern was the presence of low levels of
HDL-c in ~ 63.6 per cent subjects (Figure 4.III.2). It is understandable that with
such high prevalence of obesity and abdominal adiposity, co-morbid risk factors,
dysglycemia and dyslipidemia would be high.
The prevalence of the metabolic syndrome (MS), which is a clustering of risk
factors, is increasing among south Asian countries including India, leading to
increased morbidity and mortality due to T2DM and CVD. In the present study,
the prevalence of the MS was 43.8 per cent, which was comparable to that of 48.2
per cent reported among women inhabiting in and around Kolkata (Das et al,
2010). The increasing incidence of the metabolic syndrome among the Asian
Indians is a reason for concern if effective interventions are not applied (Misra
and Misra, 2003).
279
Table 4.III.7: Prevalence of Cardio-metabolic Risk Factors (n=162)
Cardiometabolic Risk Factors N (%)
Impaired Fasting Glucose (IFG) (≥ 100 - ≤ 125
mg/dL) 40 (24.7)
Diabetes (≥ 126 mg/dL) 30 (18.5)
Hyperinsulinimia (≥ 10.4 μU/mL) 74 (45.7)
Insulin Resistance (HOMA-IR; ≥ 2.29) 84 (51.9)
Hypercholesterolemia (≥ 200 mg/dL)
71 (43.8)
Hypertriglyceridimia (≥ 150 mg/dL) 72 (44.4)
High LDL-c (≥ 100 mg/dL) 97 (59.9)
Low HDL-c (≤ 50 mg/dL) 103 (63.6)
The Metabolic Syndrome 71 (43.8)
Figure 4.III.2: Prevalence of Cardio-metabolic risk factors in the study
population (n=162)
0
10
20
30
40
50
60
70
24.7
18.5
45.7
51.9
43.8 44.4
59.9
63.6
43.8
Per cen
t
280
4.III.5Dietary TFA Intake vis Cardio-metabolic Risk Factors:
Anthropometry, Body Composition, Clinical and Biochemical
Parameters
There is an increased prevalence of lifestyle related non communicable diseases
among Indians. These have been linked with several risk factors including high
intake of total trans fatty acids (Mozaffarian et al, 2006). Adverse effects of
chronic high intake of trans fatty acids has not been studied extensively in Indians,
particularly in reference to urban population undergoing rapid lifestyle changes.
As described earlier, in the present study the preliminary data from field work had
served as the basis for initiating and carrying out the laboratory analysis, while the
result outcomes of the laboratory analysis have been used to compute the dietary
intake of subjects under study and understanding the adverse effects of TFA
intake on their health status. Thus, in the present study an attempt has been made
to explore the effect of trans fatty acid intake with cardio-metabolic risk factors
viz, anthropometry, body composition, clinical and biochemical parameters and
search for a possible association.
Grouping of the subjects as per their TFA intake
In the present study, the mean total trans fatty acid intake was 4.91 ± 1.5g/ d and
the average per cent energy derived from total trans fats was 2.06 ± 0.58 per cent,
which is much higher than the WHO recommendation (TFA< 1 en%). To have a
deeper understanding and to arrive at proper conclusions, the subjects under study,
based on their total TFA intake (expressed as en %) have been divided in three
groups; TFA intake less than 1 en% (group 1), between 1 - 2 en% (group 2) and
more than 2 en% (group 3). In the present study, very few subjects reportedly had
TFA intake less than 1 en% (Group 1; n= 48), while the remaining had a TFA
intake either between 1 to 2 en% (Group 2; n=187) or more than 2 en% (Group 3;
n=167). These groupings were used as the basis for understanding the association
between total TFA intake and anthropometric, body composition, clinical and
biochemical parameters affecting the cardio-metabolic risk profile.
281
Intergroup differences (based on total TFA intake) in anthropometry,
body composition, clinical and biochemical parameters
A one-way ANOVA followed by Scheffe’s test was conducted to compare the
effects of total TFA intake on the mean values of anthropometric
measurements, body composition, clinical and biochemical parameters for
each of these groups. The results indicated that the mean values of weight
(p<0.01), BMI (p<0.05) and body fat per cent (p<0.05) were significantly
higher in group 2 (TFA intake between 1-2 en%) and group 3 (TFA intake >2
en%) as compared to group 1 (TFA intake <1 en%), indicative of a positive
association between total TFA intake and these parameters. When intergroup
comparison was made using Scheffe’s test it was noted that the mean value for
weight was significantly higher (p<0.05) in group 3 as compared to group 1,
while mean value for BMI was higher in both group 2 (p<0.05) and group 3
(p<0.01) as compared to group 1. Further, the mean values of these parameters
although were more in group 3 as compared to group 2 but the difference was
not statistically significant.
The mean values of other anthropometric and clinical parameters like waist
circumference (p=1.129), hip circumference (p=0.277) and diastolic blood
pressure (p=0.411) although were higher in group 3 and group 2 as compared
to group 1, these were not found to be statistically significant. However, with
respect to pulse rate and systolic blood pressure, the mean values between the
three groups did not show any significant difference (Table 4.III.8).
Similar to weight, BMI and body fat per cent, the mean values of almost all
the biochemical parameters including fasting blood glucose (p < 0.001),
fasting serum insulin (p < 0.001), HOMA-IR (p < 0.001), total cholesterol (p <
0.001), serum triglyceride (p < 0.001), LDL-c (p<0.001) and VLDL-c
(p<0.05) were significantly higher in both group 2 and 3 as compared to group
1.
Further, when intergroup comparison was made using Scheffe’s test it was
noted that the mean value for fasting blood glucose (p < 0.001), fasting serum
insulin (p<0.001), HOMA-IR (p < 0.001), total cholesterol (p < 0.001), serum
282
triglyceride (p<0.001), LDL-c (p<0.001) and VLDL-c (p<0.05) were
significantly higher in group 3 as compared to group 1. Even compared to
group 2 the mean values of fasting blood glucose (p<0.001), fasting serum
insulin (p<0.001), HOMA IR (p<0.001), and total cholesterol (p<0.05) were
significantly higher in group 3, indicating that even a slight increase in the
total TFA intake could possibly have a negative effect on these parameters.
However, in the present study the mean value of HDL-c did not depict any
significant change among the three groups. Further, the role of other
confounding factors cannot be ruled out (Table 4.III.9).
Intergroup (based on total TFA intake) differences in prevalence of
cardio-metabolic risk factors
The test of association (Chi-square and Exact test) between the prevalence of
cardio-metabolic risk factors among the three groups based on the dietary
intake of total TFA indicated that there were statistical differences between
various levels of TFA intake.
Further, the prevalence of overweight, obesity (BMI > 25 kg/m2;
waistcircumference > 80 cm; WHR > 0.8), impaired fasting glucose, type 2
diabetes mellitus, insulin resistance, hyperinsulinemia, hypertriglyceridemia,
hypercholesterolemia, high levels of LDL-c and the metabolic syndrome
increased with the level of TFA intake (Table 4.III.10).
However, statistically significant difference were present only for the
prevalence of overweight (p< 0.01), Obesity (BMI ≥ 25 kg/m2; p<0.01 and
WC > 80cm: p<0.05), impaired fasting glucose (p < 0.001), T2DM (p<0.001),
insulin resistance (p<0.001), hyperinsulinemia (p<0.001),
hypertriglyceridemia (p<0.001), hypercholesterolemia (p<0.001), high levels
of LDL-c (p<0.001) and the metabolic syndrome (p<0.001). Further, no such
trend was visible in the case hypertension and low levels of HDL-c levels.
283
Table 4.III.8: Distribution of subjects by total TFA intake and
Anthropometry/ Body Composition/ Clinical parameters(N=402)
Anthropometry,
Body
Composition,
Clinical
Parameters
Anthropometry, Body Composition,
Clinical Parameters vis Total TFA
Intake F
value*
p value
< 1.0 en%
(Group 1;
n=48)
1.0 to 2.0
en%
(Group 2;
n=187)
> 2.0 en%
(Group 3;
n=167) Overall*
Group
1 Vs 2#
Group
1 Vs 3#
Group
2 Vs 3#
Weight (kg)
62.0 ± 8.1 65.5 ± 10.0 66.9 ± 10.4 4.48 <0.01 0.096 <0.05 0.438
BMI (kg/m2) 24.6 ± 3.1 26.2 ± 4.2 26.9 ± 4.0 6.13 <0.05 0.050 <0.01 0.250
WC (cm) 85.7 ± 10.4 87.8 ± 11.9 89.3 ± 4.0 2.06 1.129 0.530 0.157 0.460
HC (cm) 96.2 ± 10.1 96.3 ± 9.6 97.8 ± 9.6 1.29 0.277 0.994 0.561 0.332
Body Fat % 33.1 ± 8.4 34.9 ± 9.1 36.7 ± 9.6 3.40 < 0.05 0.532 0.066 0.170
Pulse 81.5 ± 9.8 82.2 ± 9.3 81.1 ± 9.3 0.62 0.536 0.912 0.956 0.538
SBP (mmHg) 130.1 ± 22.1 124.8 ± 19.9 130.2 ± 20.3 3.44 0.05 0.236 0.999 0.047
DBP (mmHg) 75.7 ± 16.5 77.3 ± 15.9 79.2 ± 20.4 0.89 0.411 0.862 0.498 0.613
* ANOVA; # Scheffe’s test
284
Table 4.III.9: Distribution of the subjects by total TFA intake and
Biochemical parameters
Biochemical
Parameters
Biochemical parameters visTotal
TFA Intake F
value*
p value
< 1.0 en%
(Group 1;
n=48)
1.0 to 2.0 en%
(Group 2;
n=187)
> 2.0 en%
(Group 3;
n=167) Overall*
Group
1 Vs
2#
Group
1 Vs 3#
Group
2 Vs 3#
FBG (mg/ dL)
90.3 ± 9.5 93.5 ± 21.2 112.4 ± 25.7 15.84 < 0.001 0.835 < 0.001 < 0.001
Fasting
Serum
Insulin (μU/ mL)
9.8 ± 1.5 12.2 ± 3.9 17.9 ± 7.7 43.45 < 0.001 0.958 < 0.001 < 0.001
HOMA-IR 2.1 ± 0.3 2.3 ± 0.8 5.0 ± 2.6 46.80 < 0.001 0.937 < 0.001 < 0.001
Total
Cholesterol
(mg/dL) 163.7 ± 28.2 195.7 ± 44.8 214.6 ± 46.7 11.88 < 0.001 <0.05 < 0.001 0.043
Triglyceride
(mg/dL) 113.5 ± 32.3 144.5 ± 47.8 162.5 ± 46.1 10.44 < 0.001 <0.05 < 0.001 0.065
HDL-c (mg/ dL)
46.2 ± 8.2 48.2 ± 10.6 44.8 ± 9.2 2.07 0.13 0.703 0.840 0.132
LDL-c (mg/ dL)
93.4 ± 22.6 119.3 ± 38.0 130.9 ± 39.1 8.96 < 0.001 <0.05 < 0.001 0.180
VLDL-c (mg/ dL)
24.2 ± 7.6 29.8 ± 10.4 31.7 ± 10.9 4.56 <0.05 0.077 <0.05 0.553
* ANOVA; # Scheffe’s test
285
Table 4.III.10 Distribution of thesubjects by total TFA intake and prevalence
of Cardio-metabolic risk factors
Cardio-metabolic risk factors Prevalence of Cardio-metabolic risk factor
visTotal TFA Intake p value
Anthropometry, Body
composition and Clinical
Parameters
(N=402)
< 1.0 en%
Group 1; n=48
(%)
1.0 to 2.0 en%
Group 2; n=187
(%)
> 2.0 en%
Group 3;
n=167 (%)
Overweight * 19 (39.6) 34 (18.2) 35 (21.0) <0.01
Obesity* 15 (31.3) 108 (57.8) 102 (61.1) <0.01
Waist Circumference> 80 cm* 31 (64.6) 138 (73.8) 135 (80.8) 0.05
Waist Hip Ratio > 0.80* 33 (68.8) 132 (70.6) 124 (74.3) 0.653
Hypertension (NCEP ATP III
criteria; ≥ 130/ ≥ 85 mmHg)* 18 (37.5) 60 (32.1) 67 (40.1) 0.284
Hypertension (JNC VII
guidelines; ≥ 140/ ≥ 90
mmHg)* 20 (41.7) 64 (34.2) 68 (40.7) 0.384
Biochemical Parameters
(n=162)
< 1.0 en%
Group 1;
n=32(%)
1.0 to 2.0 en%
Group 2;
n=69(%)
> 2.0 en%
Group 3;
n=61(%)
p value
Impaired Fasting Glucose
(FBG ≥ 100 - ≤ 125 mg/dL)# 3 (9.4) 12 (17.4) 25 (41.0) <0.001
Diabetes (FBG ≥ 126 mg/dL)# 0 (0.0) 6 (8.7) 24 (39.3) <0.001
Hyperinsulinimia (≥ 10.4
μU/mL) 6 (18.8) 20 (29.0) 48 (78.7) <0.001
Insulin Resistance (HOMA-IR;
≥ 2.29) 8 (25.0) 22 (31.9) 54 (88.5) <0.001
Hypertriglyceridimia (≥ 150
mg/dL)# 2 (6.3) 30 (43.5) 40 (65.6) <0.001
Hypercholesterolemia (≥ 200
mg/dL)# 1 (3.1) 26 (37.7) 44 (72.1) <0.001
High LDL-c (≥ 100 mg/dL) 5 (15.6) 42 (60.9) 50 (82.0) <0.001
Low HDL-c (≤ 50 mg/dL) 7 (21.9) 32 (46.4) 20 (32.8) 0.206
The Metabolic Syndrome# 3 (9.4) 27 (39.1) 41 (67.2) <0.001
*Chi-square test; # Exact test
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Multivariate linear regression analysis: association of TFA intake with
anthropometry, body composition, clinical and biochemical
parameters
Although it is a cross-sectional study, an attempt has been made to study the
association of total TFA intake with cardio-metabolic risk factors viz
anthropometry, body composition, clinical and biochemical parameters. Since a
number of factors can affect the cardio-metabolic risk profile, multiple linear
regression analysis was carried out to determine the possible role of TFA intake
of the subjects and other influential factors affecting the cardio-metabolic risk
factors viz anthropometry, body composition, clinical and biochemical
parameters.
Studies have demonstrated a significant association between TFA consumption
and body weight as well as obesity. Study by Field et al (2007) carried out on
more than 41000 women who provided two measurements of weight over 8 years
demonstrated that increases in TFA consumption were robustly associated with
increase in body weight in both cross-sectional and longitudinal analysis, after
adjustment for other risk factors. In the present study, the results of the multiple
linear regression analysis indicated that among subjects with TFA intake more
than 2 en%, the mean body weight was 3.18 kg higher (p<0.05) as compared to
the mean body weight of subjects with TFA intake less than 1 en% (R2=0.29).
Other factors including age, intake of total fat, PUFA and protein emerged out to
be significant ones (Table 4.III.11) other variables included in the model were
intake of energy, carbohydrate, MUFA, SFA, cholesterol and total dietary fibre.
Similar results were noted in the case of BMI indicating that mean BMI was 2.38
kg/m2 higher (p=0.001) in subjects with TFA intake more than 2 en% as compared
to subjects with TFA intake less than 1 en% (R2=0.31). Other factors which were
noted to significantly influence BMI were age, intake of total fat, PUFA and
protein. Other confounding variables included on the model were intake of
energy, carbohydrate, SFA, MUFA, n-6 fatty acid, cholesterol and total dietary
fibre). This clearly indicated the effect of TFA intake more than 2 en% on body
weight as well as BMI. However, no significant association was noted for body
weight and BMI in subjects with TFA intake between 1-2 en%.
287
Studies have suggested that total intake of trans fatty acids is a risk factor for gain
in waist circumference (Hansen et al, 2012), however, in the present study no
significant increase was visible for waist circumference and body fat per cent
among subjects with increase in total TFA intake when adjusted for confounding
factors.
Table 4.III.11: Multivariate linear regression analysis to determine the
association of total TFA intake with body weight, after adjusting for other
factors
Factors
Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
value
Upper
value
TFA intake >
2en% 3.18 1.04 2.1 0.036 0.139 4.214
Total Fat intake 1.91 0.38 1.8 0.041 0.0391 2.468
PUFA intake 0.54 0.09 5.72 0.000 0.352 0.722
Protein intake -0.14 0.06 -2.21 0.028 -0.27 -0.020
Age 0.15 0.06 2.71 0.007 0.041 0.261
R2 = 0.29; In this model TFA intake < 1 en% was taken as the basis
Table 4.III.12: Multivariate linear regression analysis to determine the
association of total TFA intake with BMI, after adjusting for other factors
Factors Coefficient
Std.
Error t
p
value
95% Confidence
Interval
Lower
value
Upper
value
TFA intake
>2en% 2.38 0.40 3.41 0.001 0.583 5.169
Total Fat intake 0.98 0.04 2.19 0.029 0.009 1.175
PUFA intake 0.33 0.06 5.92 0.000 0.223 0.444
Protein intake -0.05 0.02 -2.39 0.017 -0.089 -0.009
Age 0.56 0.02 2.82 0.005 0.018 1.102
R2 = 0.31; In this model TFA intake < 1 en% was taken as the basis
Dietary TFA intake has been associated with dyslipidaemia and an increased risk
of T2DM and CVD (Salmeron et al, 2001; Misra et al, 2009a). In a study among
middle-aged and older Chinese individuals higher trans-18:1 levels were
associated with a lower risk of type 2 diabetes mellitus, whereas higher trans-18:2
levels were associated with dyslipidaemia (Yu et al, 2012). However, in another
288
cross-sectional study in Spanish population, TFA intake was not found to be
associated with the risk of type 2 diabetes mellitus (Papantoniou et al, 2010). In
the present study multiple linear regression analysis indicated that among the
subjects with TFA intake more than 2 en%, the mean fasting blood glucose levels
were 14.47 mg/dL higher (p< 0.001) as compared to subjects with TFA intake
less than 1 en%(R2=0.36). Other factors which were noted to significantly affect
fasting blood glucose levels were body weight, intake of energy, total fat, PUFA
and protein (Table 4.III.13). However, no association was observed between mean
fasting blood glucose levels and TFA intake between 1-2 en%, when compared to
subjects with TFA intake less than 1 en%, indicating that a TFA intake of more
than 2 en% has a higher degree of adverse effect on the fasting blood glucose
levels.
Table 4.III.13: Multivariate linear regression analysis to determine the
association of total TFA intake with fasting blood glucose, after adjusting for
other factors
Factors
Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
level
Upper
level
TFA intake >
2en% 14.47 3.49 5.58 0.000 12.580 21.368
Energy intake 2.02 0.01 1.77 0.048 -0.002 4.036
Total Fat intake 1.97 0.45 2.15 0.033 0.079 2.862
PUFA intake -1.21 0.44
-
2.76 0.006 -2.077 -0.346
Protein intake -0.44 0.26 -1.7 0.092 -0.944 0.071
Weight 1.03 0.01 2.68 0.008 0.007 2.047
R2 = 0.36; In this model TFA intake < 1 en% was taken as the basis
Studies have shown that insulin resistance is initiated in adipose tissue which in
turn affects insulin sensitivity of skeletal muscle and liver (Micha et al, 2009).
TFA have shown to increase insulin resistance and seem to have a unique cardio-
metabolic imprint that is linked to insulin-resistance and metabolic-syndrome
pathways (Bhardwaj et al, 2011a). In the present study, multiple linear regression
analysis indicated that among the subjects with TFA intake more than 2 en%, the
mean fasting serum insulin levels were 3.12 μU/mL higher (p< 0.01) as compared
to subjects with TFA intake less than 1 en%(R2=0.45) when adjusted for
confounding factors. Other factors significantly affecting fasting serum insulin
289
included age, body weight, intake of SFA and PUFA (Table 4.III.14). Research
studies in patients with T2DM have shown an elevated postprandial insulin
response with a TFA-rich diet as compared with a cis-MUFA-rich diet. However,
data regarding the dietary influence of TFA on insulin resistance in healthy
subjects are limited (Christiansen et al, 1997). Studies have also speculated that
TFA interferes predominantly with insulin signaling via intracellular kinases,
which alter insulin receptor substrates. A study on exploring the effects of diets
enriched in various fatty acids on postprandial insulinemia and fasting serum
levels of lipids and lipoproteins indicated that both dietary TFA and SFA induce
an increase in postprandial insulinemia in obese patients with type 2 diabetes
mellitus (Christiansen et al, 1997). In another study by Angelieri et al (2012) on
127 non-diabetic Brazilian individuals, TFA intake was positively correlated with
HOMA-IR.
The results of the present study indicate that the mean HOMA-IR were 1.61 units
higher (p<0.001) in subjects with TFA intake more than 2 en% as compared to
subjects with TFA intake less than 1 en% (R2=0.47). Other factors significantly
affecting the levels of HOMA-IR were body weight, intake of SFA and PUFA
(Table 4.III.15).
Table 4.III.14: Multivariate linear regression analysis to determine the
association of TFA intake with fasting serum insulin, after adjusting for other
factors
Factors Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
level
Upper
level
TFA intake >
2en% 3.12 0.70 4.48 0.003 1.743 4.490
SFA intake 0.15 0.05 3.03 0.003 0.054 0.255
PUFA intake 0.31 0.09 3.56 0 0.139 0.485
Age 0.09 0.04 2.28 0.024 0.012 0.162
Body weight 1.11 0.23 3.55 0.001 0.047 2.164
R2 = 0.45; In this model TFA intake < 1 en% was taken as the basis
290
Table 4.III.15: Multivariate linear regression analysis to determine the
association of TFA intake with HOMA-IR, after adjusting for other factors
Factors
Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
level
Upper
level
TFA intake
>2en% 1.61 0.24 6.75 0.000 1.137 2.077
SFA intake 0.49 0.02 2.89 0.004 0.015 0.818
PUFA intake 0.60 0.03 1.98 0.049 0.025 0.919
Body weight 0.27 0.01 2.68 0.008 0.007 0.472
R2 = 0.47; In this model TFA intake < 1 en% was taken as the basis
The deleterious role of saturated and trans fatty acids in glucose and lipid
metabolism has been consistently demonstrated (Kennedy et al, 2009). Several
studies have revealed that a high intake of TFA is associated with an increased
risk of coronary heart disease (Karbowska and Kochan, 2011).
Dietary TFA has shown to promote inflammation and increase the levels of
markers of inflammation, e.g. tumor necrosis factor-α, interleukin-6, C-reactive
protein and endothelial dysfunction. TFA also raise plasma total cholesterol, low-
density lipoprotein-cholesterol and triglyceride, which are risk factors of
cardiovascular diseases (CVD), while these lower the level of cardio-protective
HDL-c in plasma (Glew et al, 2010). However, the results on this are not always
conclusive, in a study among young Japanese women, the mean intakes
of total and diene TFA (0.36 en% and 0.05 en% respectively) were not found to
have any significant correlation with total, LDL or HDL cholesterol levels
(Takeuchi et al, 2012). While, in another study by Sartika (2011b) among
Indonesian adults revealed that mean intake of trans fatty acids as low as 0.48% of
total calories (urban 0.40% and rural 0.55%) showed a statistically significant
relationship between TFA intake and hypercholesterolemia and
hypertriglyceridemia.
291
In the present study, multiple linear regression analysis indicated that mean total
cholesterol levels were 9.64 mg/dL higher (p<0.01) among subjects with TFA
intake more than 2 en% as compared to subjects with TFA intake less than 1 en%
(R2= 0.32), after adjusting for confounding factors (Table 4.III.16). Other factors
significantly affecting cholesterol levels were body weight, total fat intake and
PUFA intake.
Similarly the mean LDL-c levels were also 11.8 mg/ dL higher (p<0.01) among
subjects consuming TFA more than 2 en% as compared to subjects consuming
TFA less than 1 en% (R2=0.39),after adjusting for confounding factors (Table
4.III.17). Other factors significantly affecting LDL-c were body weight, intake of
total fat, PUFA and n-6 fatty acids.Whereas, no association was noted in the levels
of these parameters with TFA intake between 1-2 en%, indicating that TFA intake
more than 2 en% can have a deleterious effect on the cardio-metabolic health of
the population.
TFA consumption has been implicated as an independent risk factor for sudden
cardiac arrest. However, in the present study no significant association could be
noted between intake of TFA and systolic and diastolic blood pressure, serum
triglycerides, VLDL-c and HDL-c levels which point towards the role of other
confounding factors. Data on physical activity pattern should have also been
gathered to have a deeper understanding of the TFA intake with cardio-metabolic
risk factors.
Table 4.III.16: Multivariate linear regression analysis to determine the
association of TFA intake with dietary cholesterol, after adjusting for other
factors
Factors
Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
level
Upper
level
TFA intake
> 2en% 9.64 3.49 3.58 0.005 5.802 19.368
Total Fat
intake 2.64 0.28 2.32 0.022 0.095 1.191
PUFA intake 0.14 0.49 4.37 0.000 1.172 3.108
Body weight 0.80 0.26 1.95 0.053 0.007 1.011
R2 = 0.32; In this model TFA intake < 1 en% was taken as the basis
292
Table 4.III.17: Multivariate linear regression analysis to determine the
association of TFA intake with LDL-c, after adjusting for other factors
Factors
Coefficient
Std.
Error
t
p
value
95% Confidence
Interval
Lower
level
Upper
level
TFA intake
>2en% 11.80 5.93 4.69 0.009 4.523 17.199
Total Fat
intake 3.20 0.08 2.41 0.017 0.364 5.368
PUFA intake 1.83 0.39 4.72 0.000 1.066 2.601
n6 intake 0.09 0.05 1.78 0.077 -0.009 0.180
Body weight 2.00 0.91 1.68 0.032 0.301 3.105
R2 = 0.39; In this model TFA intake < 1 en% was taken as the basis
Thus, the present study indicated significantly higher levels of most of the cardio-
metabolic risk parameters viz weight, BMI, Fasting blood glucose, fasting serum
insulin, HOMA-IR, total cholesterol and LDL-c, among subjects with TFA intake
2 en% as compared to subjects with TFA intake less than 1 en% when adjusted for
their respective confounding factors. However, an increase in the total TFA intake
from less than 1 en% to between 1-2 en% did not show any significant increase in
these parameters.
Further, in the present study, high TFA intake (between 1-2 en% or >2en%) did
not indicate to have any significant effect on parameters like body fat %, waist hip
ratio, systolic/ diastolic blood pressure, serum triglycerides and HDL-c levels
The present study highlighted that apart from hydrogenated fats, TFA was also
present in some edible oils which otherwise are considered free from trans fatty
acids. Further, the results depict that commonly consumed fried and baked food
items have substantial amounts of TFA, with most of them containing TFA
content that was much higher than the tolerable limit of 2% of total fat enforced in
Denmark, the only country in the world that has a legal limit for trans fatty acids.
The study also demonstrated that although the oils under study as such do not
contain TFA, when subjected to heat, their TFA content increases on heating/ re-
293
heating or when they are used for frying/ re-frying depending on temperature. The
study also highlighted that in the case of edible fats (Desi ghee/ vanaspati), which
already contain TFA, when subjected to heat/ re-heat, their TFA content increased
further.
Further, the study highlighted that despite the study population being highly
educated, their knowledge regarding TFA were negligible and cooking and frying
practices were rather poor and their frequency of consumption of outside foods,
which are high in energy, total fat and TFA was quite high. The study also
demonstrated that in the population under study the consumption of fats, TFA in
particular was higher than the recommendation by ICMR/ NIN/ WHO guidelines
for prevention of non-transmittable chronic diseases, which are a leading cause of
death worldwide. Although it is a cross-sectional study, still it is able to show
some relation between TFA intake and cardio-metabolic risk factors, highlighting
the need for detailed intervention study.
4. IV LIMITATIONS AND STRENGTHS OF THE STUDY
Limitations And Strengths Of The Study
Due to financial and logistic constraints the study suffered certain limitations.
Field Work
The results of this study cannot be generalized for the population at large
as the subjects for this study were a group of female school teachers
representing the educated MIG/ UMIG group. Despite a large sample size,
our results apply to a relatively healthy set of women; our estimates may,
therefore be too conservative.
Since dietary intake was self-reported, it could be subject to reporting bias
though due precautions and check were observed during 2 day dietary
recall (1 working and 1 non-working day) and while administering food
frequency questionnaire.
Being a cross-sectional study, no concrete cause/ effect inferences can be
drawn from the dietary intake of the subjects.
The physical activity profile, which could also have thrown light on the
relationship between TFA intake and cardio-metabolic parameters, could
294
not be included in the present study due to time and resource constraints.
However, in the present study, this fact can be said to have lesser
relevance since all the subjects were female school teachers representing
the urban female population belonging to middle and upper middle income
group families, having a hectic and mechanised lifestyle.
Laboratory Analysis
Due to financial and time constraints, the laboratory analysis of fatty acid
profile including that of TFA for heated/ re-heated fats/ oils as well as that
of the food items itself could not be carried out for a still larger number of
samples.
The test food (pre-frozen French fries) could not be tested for the fatty acid
profile including TFA after frying.
Due to high variability in methods of food preparation, dietary habitsas
well as time/ resource constraints, fatty acid profile including TFA content
of a composite diet sample could not be done. However, due precautions
have been taken while entering the dietary data particularly giving due
emphasis to the type and amount of fats/ oils reported by the subjects.
The focus of the present study was to see the formation of TFA in fats/ oils
exposed to continuous heating/ re-heating at varying temperature, thus the
effect of heating and re-heating at the same temperature such as 180ºC has
not been assessed.
STRENGTHS OF THE STUDY
The present study is one of the few reporting the TFA content of fats/ oils
samples, its formation during heating/ re-heating and the dietary intake of
TFA in urban, north-Indian female population belonging to MIG/ UMIG
families.
This study will help in overcoming the lacunae relating to the TFA content
of commonly consumed fats/ oils/ foods items in India and will help in
generating a data base of laboratory analysed values of TFA of select
Indian fats/ oils/ food items.
Through the results of this study, it can now be established that trans fats
even if are absent in a particular oil initially, can still be formed during
295
heating/ frying. Thus, this study will open new dimensions for carrying out
future researches on ways to curb TFA formation during processing of
fats/ oils or their use in frying.
The present study can be used as a tool to help the government in driving
the food industry to come up with healthier options for the population at
large and persuading the government to put a strict check on the quality of
prepared foods available at eating outlets including road side vendors,
specifically pertaining to their TFA contents.
Further, the present study can be used to showcase the current scenario
regarding TFA consumption in India, and can later be used in studies
showing the secular trends.
The results of the present study will go a long way in helping educate the
masses regarding serious health effects of TFA consumption and also ways
and means to minimise formation of TFA at household and commercial
level by adopting healthier cooking practices for a better health.
Although it is a cross-sectional study, still it is able to show some relation
between TFA consumption and cardio-metabolic risk factors, highlighting
the need for detailed intervention study.
The study emphasizes, on the urgent need of limiting the levels of trans fatty acids
in the food supply. To achieve this, new technologies can be employed to reduce
the presence of trans fatty acids from edible fats/ oils. A variety of technologies
have already been implemented in the developed nations, while others are being
developed and refined to reduce or eliminate TFA in food products (Stender et al,
2006b). The most successful technologies are interesterification (which rearranges
the fatty acid within triglycerides to yield customized melting characteristics),
while the other one is altering the hydrogenation process to yield partially
hydrogenated fats lower in TFA (accomplished by using metal catalysts that
prevent the formation of trans isomers or promote the formation of cis isomers
and by changing the time and temperature of the hydrogenation process). Further,
numerous plant breeding and genetic engineering technologies are being used to
manipulate the fatty acid composition of oil seeds to increase oxidative stability
296
during deep-fat frying and to extend shelf life by decreasing the amount of
relatively unstable fatty acids (i.e. linolenic acid) or increasing the amount of
relatively stable fatty acids like oleic acid.
It is suggested that the future trend of having “zero trans fat” food products can be
achieved through several approaches, which include nutrition recommendations,
mandatory labelling and reformulation of food products to remove TFA. It should
be made mandatory for the manufacturers to comply with safe limits of TFA in
their products and accordingly incorporate the information on the label. With
respect to the direct approach relating to food products reformulation, the major
concern is with regard to the partially hydrogenated vegetable oils (PHVO),
because ruminant fats cannot be entirely removed from the diet, moreover, their
intake is rather low.
Due to the high TFA content, replacement of PHVO becomes rather mandatory;
and that these should be replaced byvegetable oils which are free from trans fatty
acid and have low saturated fatty acid and high cis-unsaturated fatty acid content.
Animal fats and tropical oils should be avoided to replace partially hydrogenated
vegetable oils due to their high saturated fatty acid levels. Products that have a
lower TFA and saturated fatty acid tend to cost more, and this may be a barrier to
their use by the budget conscious consumers, thus attempt should be made in the
direction of development of healthier fats/ oils and food products at economically
reasonable prices.
Further, with diabetes and heart disease emerging as the leading cause of death/
disability among Indian population, it is imperative that the consumers become
aware of the harmful effects of TFA, its sources and healthier options available for
maintaining their metabolic health. Therefore, educating Indian population
regarding effective ways of avoiding TFA in their diet is of immediate
importance.
Recommended