N. R. Reddy

Dry bean tannins: A review of nutritional implications

Tannins are one of several antinutritional factors present in dry beans and are located mainly in the seed coat or testa. The tannin content of dry beans ranges from 0.0 to 2.0% depending on the bean species and color of the seed coat. Many high tannin bean varieties are of lower nutritional quality than low tannin varieties of beans. Naturally occurring food legume tannins are reported to interact with proteins (both enzyme and nonenzyme proteins) to form tannin-protein complexes resulting in inactivation of digestive enzymes and protein insolubility. Both in vitro and in vivo studies indicate that bean tannins decrease protein digestibility, either by inactivating digestive enzymes or by reducing the susceptibility of the substrate proteins after forming complexes with tannins and absorbed ionizable iron. Other deleterious effects of tannins include a lowered feed efficiency and growth depression in experimental animals. The antinutritional activity of bean tannins can be reduced by processing (1 or a combination of 2 or more methods), for example dehulling, soaking, cooking and germination. Genetic selection also may help in breeding varieties low in tannins. Potential chemical treatments such as use of tannin complexing agents are discussed.

Chemical, nutritional and physiological aspects of dry bean carbohydrates—A review

Abstract The current knowledge of dry bean carbohydrates related to their composition, nutritional value and physiological attributes in humans is reviewed. Dry bean carbohydrates represent up to 60% of the total seed weight and starch is the major constituent. Molecular and physicochemical properties of legume starches are also discussed. Data to indicate the possible involvement of the raffinose family of oligosaccharides in flatulence production are given.

Legume‐based fermented foods: Their preparation and nutritional quality

Legume-based fermented foods are very popular in the Southeast Asia, the Near East, and parts of Africa. They form an appreciable part of daily diet of people as a main source of protein, calories, and certain vitamins. Preparation of legume-based fermented foods has remained to some extent an art, and their nutritional quality has been of interest to both professionals and layman. The fermentation process helps not only in improving the organoleptic quality of legumes but also enhances nutritional quality. This review examines the production of various legume-based fermented foods and critically assesses their nutritional quality.

Biochemistry of black gram (Phaseolus mungo L.): a review.

Black gram is one of the less‐known legumes, mainly grown and consumed in India, Thailand, and other tropical parts of the world. This review presents the information on black gram (Phaseolus mungo L.) proteins (albumins, globulins, prolamins, and glutelins), minerals (calcium, magnesium, phosphorus, zinc, and iron), vitamins, lipids, phytic acid, carbohydrates, antinutritional factors (α‐amylase inhibitor, trypsin and chymotrypsin inhibitors, tannins, and phytohemagglutinins), and flatulence production in rats following ingestion of black gram processed products. Effects of different food processing operations (germination, cooking, and fermentation etc.) on black gram proteins, carbohydrates, phytic acid and flatus factors are also discussed.