CHEMICAL-COMPOSITION OF 3 UNDERUTILIZED LEGUME SEEDS GROWN IN CHINA

Proteins of Phaseolus angularis, Phaseolus calcaratus and Dolichos lab lab seeds (24.9 to 26.5% dry weight) were mainly contributed by their cotyledons which had a proportion of 82.9 to 90.8% by weight of the wh ole seeds. The levels of all the essential amino acids of the legume s eeds (415 to 443 mg g(-1) protein) were above the FAO/WHO requirement with the essential amino acid scores of the methionine and cystine bei ng 1.02 to 1.19. Appreciable amounts of oligosaccharides of the raffin ose family were found mainly in the cotyledons (3.52 to 4.72% dry weig ht). The total dietary fibre of the legume seeds (13.5 to 19.3% dry we ight) consisted predominantly of insoluble dietary fibre (IDF). The co tyledons contained 45.9 to 51.4% dry weight of starch but had low cont ents of cellulose and lignin. Hulls were highly lignified and consiste d predominantly of IDF, with values ranging from 70.7 to 74.0% dry wei ght. The principal sugar residue analysis revealed that pectins were t he major polysaccharide present in the SDF of both the cotyledons and the hulls. While xylans and cellulose were the major polysaccharides p resent in the IDF of the hulls, xyloglucans and arabinose-rich pectic substances were the principal non-starch polysaccharides in the IDF of the cotyledons. (C) 1998 Elsevier Science Ltd. All rights reserved.