The amino acid composition of triticale grain as a function of nitrogen content: Comparison with wheat and rye

Triticale grains (19 samples from seven different varieties) with total nitrogen content, N , ranging from 1·7 to 3·7 % of grain dry matter, were analysed for their amino acid compositions with high accuracy from six different hydrolysates per sample. On a dry matter basis, amino acid contents in grain increased as linear functions of N with correlation coefficients higher than 0·97 for most of them in all the triticale genotypes and phenotypes studied. Hence, the amino acid composition of any triticale can be predicted from its N value. Protein amino acid contents changed as hyperbolic functions of N ; contents of Phe, Pro, Glx and amide nitrogen increased, Leu, Ser and Tyr remained constant, and other amino acids decreased. The hyperbolic variations of the recovery of analyses, non-protein nitrogen content, degree of amidation and nitrogen to protein conversion factors were determined as a function of N . A comparison based on previous similar determinations on wheat and rye confirmed that triticale proteins are often intermediate between those of wheat and rye. However, they were richer than both parental species in essential amino acids for N less than 1·8 (Thr and Tyr), 2·0 (Tip), 2·5 (Met), 3·0 (Cys) and 2·3 (Lys).