The amino acid composition of rice grain as a function of nitrogen content as compared with other cereals: A reappraisal of rice chemical scores

Brown rice grains (eight samples from different varieties) with nitrogen content, N , ranging from 1·27 to 2·07 % of grain dry matter, were subjected to accurate amino acid analysis. Amino acid contents in grain dry matter increased linearly with N with correlation coefficients close to one. A comparison with numerous literature data (with 0·8 N N for all phenotypes and normal genotypes. Amino acids in grain protein changed as hyperbolic functions of N , which significantly decreased for Lys, Met and Cys when N N , rice proteins were shown to be richer in Lys than wheat, maize and sorghum for any N values, but poorer than those in barley, rye and triticale for N N = 1; it remained poorer than those in maize for all N values, but became richer than those in sorghum, oat and Triticeae for 1 N N and was very close to that of wheat.