CHANGES IN THE DIETARY FIBER (RESISTANT STARCH AND NONSTARCH POLYSACCHARIDES) CONTENT OF COOKED FLOURS PREPARED FROM 3 CHINESE INDIGENOUS LEGUME SEEDS

The effects of cooking on the dietary fiber (DF) content, which includ ed resistant starch (RS) and nonstarch polysaccharides (NSP), of flour s from Phaseolus angularis, Phaseolus calcaratus, and Dolichos lablab seeds, indigenous to China, were evaluated. The cooked legume flours w ere prepared by milling boiled and freeze-dried legume whole seeds. To tal DF contents of all cooked flours were higher than those of the raw ones. The results showed an increase of NSP and RS to various extents with increasing cooking time of the flours. In the NSP of the legume flours, both the soluble and insoluble fractions increased during cook ing, and a redistribution of the soluble and insoluble NSP components was observed. Generally, cooking increased the solubilization of the N SP in the legume seed flours, which might be important for their use a s soup ingredients for therapeutic purposes. The increase of RS in the legume flours could be mainly due to the presence of cell-enclosed st arch and retrograded starch formed during cooking. Such increase in th e RS content of the cooked legume flours might have beneficial physiol ogical effects for humans.