AMINO ACID COMPOSITION AND NITROGEN-TO-PROTEIN FACTORS FOR GRAIN LEGUMES

Abstract

Eleven grain legumes were analyzed for amino acids (AA), AA scores and essential AA indexes (EAAI). Nitrogen-to-protein (N:P) factors were determined from these data. Concentrations of AA per gram of nitrogen were relatively constant among species with the exception of the AA arginine, methionine, tryptophan and cystine which had coefficients of variation of 23–30%. On average, arginine, leucine, lysine, aspartic acid and glutamic acid accounted for 50% of the total of all AA. These grain legumes met adult human requirements for essential AA except for methionine and cystine which were deficient in all species. This resulted in an average AA score and EAAI of 56 and 89, respectively. The N:P factor was 5.6 for the 11 species but this value was 5.0 if corrected for nonprotein nitrogen.