Factors affecting the nutritional quality and accept ability of mung bean ( vigna radiata ( l . ) wilzeck ) *

The nutritional quality and acceptability, as well as factors affecting these characteristics, of nutritionally and economically important mung bean were studied. Mung bean has a relatively high protein content ranging from 21 to 25% and a chemical score of 65% based on its amino acid composition, and cysteine and methionine as limiting amino acids. Mungbean PER increases two to three­ fold when it is dehulled, sprouted and/or cooked indicating presence of anti­ nutritional factors. The trypsin inhibitor activity (TIA) of mung bean ranges from eight to 10 units/mg protein. Boiling mung bean in water for 30 min. decreases TIA by 98% while roasting in 20% residual TIA. Polyphenols in mung bean have low protein precipitating capacity, relative­ ly high flavanol levels and are concentrated in the seed coat. Soaking seeds in water reduces assayable polyphenol content from 24 to 50%. Boiling further reduces polyphenol content to 73%, but not roasting which reduces it to only 17%. Mung bean sprouts have 36% less polyphenols than the mature seeds. Con­ densed tannins isolated from mung bean decrease in vitro protein digestibility of mung bean by 3-6%. Oligosacchrides which produce flatulence are present in mature seeds of mung bean and are not detectable in mung bean sprouts. Hemagglutinins follow a similar trend. Hard seeds o-.: "patol" range from 0 to 3.8% in four varieties and four seed lots of mung bean analyzed. After boiling, hard seeds remain uncooked, are hard, brownish and wrinkled. They have thicker seed coats and are twice as hard as normal seeds. Hardseededness can be accounted for by the significantly high lig­ nin and silica content in the seed coat of mung bean. This report also summarizes relevant work on mung bean by other workers. *Paper presented during the Annual Scientific Meeting of the National Academy of Science and Technology, July 8, 1988, Manila Hotel.