Seed protein of millets: amino acid composition, proteinase inhibitors and in-vitro protein digestibility

Abstract

Six varieties of common millet ( Panicum miliaceum), three varieties of finger millet ( Eleusine coracana) and four varieties of foxtail millet ( Setaria italica) were analyzed to determine the nitrogen constituents, amino acid composition, proteinase inhibitors and in-vitro protein digestibility (IVPD). The non-protein N accounted for 17·3, 12·5 and 17·0% of the total N found in common millet, finger millet and foxtail millet, respectively. Millet proteins were deficient in lysine, but contained adequate levels of the other essential amino acids. The proteins in finger millets were better balanced compared to those in common millet and foxtail millet. Little varietal differences were observed within millet types in terms of amino acid concentrations. The anti-tryptic activities of millets were high compared to their anti-chymotryptic activities. Foxtail millet had no detectable anti-chymotryptic activity. The IVPD values of raw, uncooked millets were low, but were improved by cooking.