According to the United Nations Food and Agriculture Organization (FAO), the Philippines and India are among the developing countries with high levels of obesity and under-nutrition.

A 2011 survey by the Food and Nutrition Research Institute (FNRI) showed that 22.3 percent of Filipino adults are overweight, 6.1 percent are obese and is expected to increase significantly by 2015 .

The Potential of Lima Beans (Phaseolus lunatus L.) as a source of Resistant Starch and Food Applications

Rhilen Audrey D. Teodoro

OBJECTIVES:

1. to tackle the principles of Resistant Starch

2. to discuss the significance of resistant starchvarious body processes

3. to enumerate and run through varioussources of Resistant starch

4. to discuss the significance of lima beans as asource of RS and;

5. to offer possible applications of lima beansstarch in food/ product development

STARCH the major dietary source of carbohydrates

Polysaccharides; composed of a number of monosaccharides or sugar (glucose) molecules linked together with alpha-(1-4) and/or alpha-(1-6) linkages

Two main structural components

AMYLOSE a linear polymer in

which glucose residues are alpha-D-(1-4) linked

constituting 15% to 20% of starch

AMYLOPECTIN larger branched

molecule with alpha-D-(1-4) and alpha-D-(1-6) linkages

a major component of starch

RESISTANT STARCH “the sum of starch and products of starch degradation not absorbed in the small intestine of healthy individuals” (Murphy et al.2008).

considered the third type of dietary fiber as it delivers some benefits of insoluble and soluble fiber.

Types of Resistant Starch

Source: Sajilata, Singhal & Kulkarni (2006)

Why Resistant Starch?

Resistant Starch

Enhanced fermentation and laxation in the large intestine

decrease in pathogenic bacteria in the gut

Resistant Starch “Intakes of 17 to 30 g resistant starch from potato, banana, wheat, and corn resulted in significant increases in fecal weight and short-chain fatty acid excretion” (Cummings et al.1996; Murphy et al.2008;)Dietary fibre and resistant starch, as they ferment in the large bowel, produce high levels of butyric acid or its salts (Sharma et al., 2008)

Does not directly contribute to blood glucose level

Resistant Starch

plasma glucose and insulin responses were seen to lower after adults with untreated borderline diabetes were fed with meals containing 11.5 g resistant starch (Behall and Hallfrisch, 2002).

Resistant Starch

inhibits fat accumulation

◦ Number of studies examined the potential of RS to aid in oxidation of fats and its satiety functions to aid in weight management.

◦ Tapsell (2004), proposed that eating foods rich in RS may promptly mobilize fat stores as insulin secretion is reduced.

Resistant Starch

introducing bioreactive functional food component such as RS in the diet is a natural way to increase gut hormones which are effective in reducing energy intake and a natural way to treat obesity (Keenan et al.2006; Fuentes-Zaragoza et al., 2010)

Sources of Resistant Starch

Source: Sajilata, Singhal & Kulkarni (2006)

Lower digestibility compared to cereal starch (Tharanathan and Mahadevamma,2003). Legumes have high content of both soluble and insoluble dietary fiber. They are more prone to retrogradation

Why legumes?

“butter beans” or baby lima are small varieties grown as bush while pole or vine varieties are called Lima Beans Used in wide variety of dishes good source of reasonable quantities of proteins, vitamins, certain minerals, and are an excellent source of complex carbohydrates and dietary fiber.

Lima Beans

Peruvian Pallar

Madagascar lima bean

Patani lima bean

Persian lima bean

Sieva lima bean

Zebra lima bean

Source: http://www.selfsustainable.co.za/

Lima Beans Biliarderis et al (1981) found out that lima bean starch was hydrolysed to a lower extent (47%) than starches from mungbean ( 68%) and lentil ( 71%). � �

Comparable results was attained from the study conducted by Hoover and Sosulski (1985) that showed that lima bean starch soaked at 2.2 N HCl at 35◦C was more resistant to α-amylosis than other legume starches with only 3% hydrolysis in 9 hours.

Amylolytic susceptibility of native starches viewed under SEM

Source: Hoover, Rorke & Martin (1991) a) Lima beans starch b) corn starch c) potato starch

Lima Beans

Source: Murphy, Douglass and Birkett (2008)

A study performed by Bello-Perez et al (2007) using starch from three varieties of cooked lima beans found out that RS present ranges from 38 and 45 g/kg ( 3.8 and 4.5%) �concluding low digestion rate and suggesting ‘slow carbohydrate’ feature. Tovar and Melito (1996) however observed 30.7% RS from isolated lima beans starch through steam-heating.

Lima Beans

Lima Beans High amylose content of lima beans (32.7%) compared to that of other cereal and tuber starch (Bentacur-Ancona et al, 2001).

High amylose= high retrogradation = high RS3

ApplicationFlours and protein isolates from Lima beans is reported to have good water-holding capacities with values ranging between 2.65 and 3.80 g/g sample (Chel-Guerrero et al, 2002).

ApplicationThicken opaque health beverages in which insoluble fiber is derived.

ApplicationProtein content of native starch was lower than 0.20% making it a feasible source of high glucose content syrups (Bentacur-Arcona, 2001).

ApplicationRS3 allows for the addition of high levels of materials which still functions like fiber but does not interfere with structure and will work for extruded products (Zallie, Altieri, Chiu and Henley, 1996).

CONCLUSIONNot all starches are made equalStarch from lima beans has a promising use as flour substitute due to its desirable physicochemical properties. It can also be used in the production of extruded products as it improves air cell expansion as compared to fiber

RECOMMENDATIONSperform in depth studies and analysis of lima beans encompassing the varieties that can be found in the country.Incorporate lima beans in food/product development as it can create demand for the plant

Acknowledgment

REFERENCES