UNIVERSITY OF NAIROBI

Department of Food Technology and Nutrition

Industrial Project: Production of ready to drink tea

Submitted in partial fulfillment of a degree in Bachelor ofScience in food Science and Technology

Name: KEN OBURA

Reg No: A24/0159/2000

t\A.vJ •Supervisor: Prof..Jl.=M.OKOTH

.«ABLE OF CONTENTS PAGE

Introduction 1Literature review 2Research problem 4Experimental design 5General processing flow diagram 6Analytical methods 7Results 8Discussions 9Conclusion and recommendation 10References 11

INTRODUCTION

Tea is the most popular beverage in KenyaIn the Kenyan tea industry there are two sectors.

a) small scale farm known as small holdersb) large scale farm known as estates

The main tea growing areas are situated in or around the highlands area on either side ofthe great side of rift valley at altitudes ranging 1500-2700.

Tea production continues all year round with two peak seasons between march and Julyand October to December. These two seasons coincide with long and short rainsrespectively60%oftotal production is by the small holders which are generally under Kenya TeaDevelopment Agency (KTDA).KTDA advice the farmers on crop husbandry. Assist inbulk purchase of input and manage the factories on behalf of the farmers.The remaining 40% of the total production is by the large scale farmers whose operationsare controlled by the tea board of Kenya.

In Kenya today the tea industry is a leading foreign exchange earner and remains thegreatest player with regard to rural industrialization. This sector sustains a significantpopulation either directly or indirectly given that Kenya is the third largest tea producingcountry in the world

In spite of this extensive production of tea in the country there is no ready to drink tea inthe Kenyan market.

This project is therefore design to investigate the possibility of producing an acceptableand stable ready to drink tea from green tea and honey as the sweetener.

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LITERATURE REVIEWGREEN TEA

Tea is made from the tender leaves and terminal buds of the plant Camellia sinensis.This plant originally grew in the bush and has been in existence for about 2000-3000years.lt is believed to have been discovered in China.In Africa tea was first grown in South Africa in 1850.In Kenya it was introduced in 1990during which tea farming was reserved exclusively for the white settlersTea processing generally produce three types ofteas

a) Black teab) Oolong teac) Green tea

In the manufacture of black tea there is complete fermentation of the macerated tea leavesIn oolong tea there is partial fermentation of the tea leaves. The partially fermented tealeaves are then dried.In green tee leaves there is no fermentation of the tea leaves .After maceration of tealeaves 'there is heat treatment of the leaves to inactivate the enzymes necessary forfermentation.

This project however is aimed at using unprocessed tea leaves for production of intendeddrink.

Chemical composition of fresh tea shoots (%)InsolubleCrude fibre, cellulose, ligninProteinsFatsChlorophyll & pigmentPectinStarchesTotal

221681.540.552

Fermentable polyphenolsOther polyphenolsCaffeineSugers and gummy matterAmino acidsMinerals (ash)

20104374

Total 48

Tea shoots contain appreciable amounts of polyphenols and hence are preferred as rawmaterials for tea beverage manufacture .The concentration of polyp heno Is reducesdownwards from the bud to the stalk, A tea shoot consisting of two leaves and a terminal

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shoot which consist normal and best material for tea manufacture contains 74 to 77%moisture (surface dry shot) and 23 to 26% solid matterIn this project it's the soluble part which is of interest. The soluble part includes aboutsome 30 polyphenolic bodies, over 20 amino acids, caffeine, sugars, organic acids andtrace essential oils.

Health Benefits Of Green teaTea comes from Camellia sinensis the only plant that makes theanine. Unique to tea is amajor amino acid in black, green and oolong tea. Exciting recent research has shown thattheanine may play an important role in the natural gentle stimulatory effect of drinkingtea. Tea also contain antioxidants called flavonoids. Antioxidants can help the bodyprotect its self against free radicals -molecules that can damage the cellsThe American Dietetic Association in its Position Paper on functional foods includedblack and green tea as functional foods. Based on the available scientific research thepaper stated that the health benefits of drinking black or green tea include possiblereduced risks for coronary heart disease, as well as gastric, esophagealus and skincancers. The paper also says that tea help strengthen the body's immune system, protectteeth by inhibiting plaque bacteria, potentially fight free radicals produced duringstrenuous exercise and possibly increase calories burned during everyday activities.These facts show that consumption of tea has a lot of health benefits.This project is therefore, intended to increase the consumption of tea.

HONEYVirtually all Kenyans use refined sugar as the source of sweetening for their teas. This isattributed to the fact that refmed sugar is readily available in the market, its cheap andtherefore affordable. However there are alternatives to the use of refined sugar and honeyis one of them.This project focuses on the use of honey as source of sweetening because of its immensehealth benefits.Honey contains antioxidants which are responsible for the destruction of free radicalsin the body. This has a resultant effect of preventing heart diseases and cancer.Honey also contains vitamins B 1,B2,B3,B5,B6 and C, whose roles are a commonknowledgeIt also contains minerals such as magnesium ,potassium ,calcium ,sodium ,chlorine andiron.it also acts as antibacterial and antifungal agent and speed up the healing process ofwounds and burns.Whereas the project does not aim at evaluating the health benefit of green tea honey,these facts can be utilized so that the ready to drink product has immense health benefitswhich could be evaluated in another project.

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RESEARCH PROBLEM

The consumption of tea has been very high. This is due to high production of tea inKenya coupled with facts that the consumers have embraced tea as their first choice ofthe beverage drinks. However there is no ready to drink: tea in the in Kenyan market.The project is aimed at introducing a ready to drink tea in the market.

JUSTIFICATION

The project aims at producing a stable and an acceptable product from green tea andhoney which has the following benefits.1. provide convenience of having a ready to drink tea in the market.2. provision of a more diversified market of ready to drink beverage3. increased consumption of green tea in Kenya

OBJECTIVETo produce a stable and an acceptable ready to drink tea from green tea using honey asthe source of sweetening

SUB-OBJECTIVES1 Establish the product shelf life2 Sensory evaluation3 Determine titratable acidity4 Detemine PH

HYPOTHESISHO; the tea will be acceptable to the consumers.HI; the tea will not be acceptable to the consumers.

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EXPERIMENTAL DESIGNThe research involved varying the concentration of green tea brew and concentration ofhoney as shown in the table below. Seven samples were used.

sample 1 2 3 4 5 6 7Green tea 10 9 8 7 6 5 4(g/100ml)Honey (ml) 5 10 15 20 25 30 35

MATERIALRaw materialsGreen tea leaves were obtained from Murang'a district. Honey was obtained fromNakumatt supermarket.

ChemicalVarious chemicals of analytical grade were supplied by the food science and technologylaboratory .

PROCESSING METHODS.The green tea leaves were washed and then chopped. These were then dipped in hot waterand then filtered to get the tea brew. The tea brew was then heated. Honey was addedfollowed by citric acid and pectin enzymes (pectin esterase). It was then pasteurized(boiled at 75°C for 5 minutes) then cooled before bottling.It was then stored for several days and changes in organoleptic properties noted.

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GENERAL PROCESSING FLOW DIAGRAM

Green tea leaves

~Washing

~

Hot water treatment

~Filtering

~

Brew

Honey

~

Citric acid

Pectin enzyme

~Boil

~

Cool

Bottling

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The hedonic 7-point rating was used to indicate the degree of acceptability of theorganoleptic properties by a group of 16 panelists who were presented with the sevensamples to test and rate. The table below shows the design of the hedonic 7-point ratingused.

PROPERTIES SI S2 S3 S4 SS S6 S7APPEARENCECOLOURTASTEMOUTH FEELOVERALLACCEPTIBILITY

ANALYTICAL METHODSDetermination of phA ph meter was used to determine the ph of the samples.

Determination of Titrable acidity10ml of each sample was pippeted into a conical flask and heated to boiling. SOml ofdistilled water was added followed by a few drops of phenolphthalein indicator .Themixture was titrated with O.INaOH solution. The acidity was then calculated andexpressed as % equivalent citric acid.

Determination of shelf lifeEach sample was placed under accelerated storage temperature at 5S°C. Changes in theorganoleptic properties were monitored after every day.The shelf life was calculated with each day being equivalent to one month

Sensory EvaluationThis was based on the hedonic rating test.A seven point hedonic scale ranging from"like very much" to "dislike very much" was used. The panel consisted of 16members. The panelist were presented with the seven samples and rated them accordingto overall acceptability, mouth feel, taste, color, odour and appearance based on theseven point hedonic scale. The results were analyzed using averages of the score givenby the panelists.

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RESULTS

Raw materialsGreen tea brew

PH= 5.6TTA=0.08%

HonevPH=3.9TTA=0.21%

PRODUCT ANALYSIS RESULTS

PARAMETER SI S2 S3 S4 S5 S6 S7

TTA (%) 0.08 0.09 0.11 0.13 0.15 0.18 0.19

It..

PH 5.7 5.4 5.2 4.9 4.6 4.4 4.2

2 2 2 3 3 3 4Shelf life(months)

2 4 5 6 7 5 4Appearance

color 3 4 5 7 6 5 2

taste 3 4 7 5 4 4 2

Mouth feel 3 4 6 5 5 4 2

Overall acceptability 3 4 6 5 5 4 2

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DISCUSSIONS

SHELF-LIFEFrom the results obtained sample 7 had the longest shelf life. This could be attributed tothe fact that sample 7 had the lowest pH which was responsible for inhibiting microbialgrowth that would cause faster spoilage.Sample 1, 2, 3 had the shortest shelf life due to their high PH that would permit thegrowth of spoilage micro organisms

APPEARANCESample 5 was most preferred. This could have been due to the average concentration ofhoney and tea that were usedSample 1 was the least preferred according to the results given by the panelist. This isprobably because of the concentration of tea was too high resulting in high viscosity.

COLOURColor forms part of appearance. From the results obtained sample four was the mostpreferred with its pale brown color. While sample 7 which had black color was leastpreferred.

TASTETaste is a component of flavor .The other component of flavor is odor or smell. The tasteof the product was influenced by chemical compounds inherent in the green tea andhoney. Sample 4 was most preferred while sample 7 was the least preferred.

MOUTH FEELMouth feel is a combination of texture and the flavour of the product .From the resultsobtained, sample 3 was the most acceptable while sample 7 was the least preferred.

OVERALL ACCEPTABILITYThis is a factor that is determined by all the above parameters i.e. taste co lour mouth feeland appearanceThis means that since all the above parameters have an interactive effect on each othertheir result will determine the general acceptability of the product ,From the results it canbe deduced that sample 3 was the most preferred while sample 7 was the least preferred

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CONCLUSION AND RECOMEDATION

From the above experiment and results obtained its clear that production of ready to drinktea from green tea and honey is possible. However from the results obtained its alsoevident that the above combination is not the best for some quality aspects such asappearance, color and taste. This will call for modification of the appearance color andtaste so as to match those of samples 5,4 & 4 respectively. Color could be improvedaddition of caramel color. Appearance can be improved by further clarifications whiletaste could be improved by adding natural flavors such as strawberry, lemon et.

A recommendation to this project is that the nutritional value of the product should beevaluated in another project.

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REFERENCES1) Workhoven, 1974.2) Tea technology notes by Prof Okoth3) Jelliunek G, 1985. Sensory Evaluation of Food.4) Hick, D, 1990 Production and packaging of carbonated fruit juices and fruit

beverages.

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