Characteristic of the nutritive value of the protein from rye caruopses. I. Amino acid composition of protein and the nitrogen forms in the caryopses of ten rue varieties from the breeding collection

Abstract

Total and soluble nitrogen, protein and non-protein -nitrogen was determined as well as the amino acid composition of the caryopses of ten rye varieties including three bred in Poland and cultivated on a commercial scale: 'Dańkowskie Złote', 'Dańkowskie Selekcyjne' and 'Borkowskie Tetra'. and seven foreign varieties characterized by a high total protein content (11.9-16.4% in dry weight). In the varieties examined the amount of protein nitrogen increased in the same degree as did the content of total nitrogen. The amino acids limiting the nutritive value of the protein in rye caryopses were mostly lysine and methionine, and in the varieties with high protein content tryptophan. The low-protein varieties had a relatively higher content of lysine, sulphur amino acids, tryptophan and other amino acids (as % of protein) than the high protein ones, but their absolute amino acid content (as % of dry weight) was lower.