PROTEIN CONTENT AND AMINO ACID COMPOSITION OF TISSUE COMPONENTS IN DEVELOPING BARLEY

Abstract

ABSTRACTFour hulled barleys were harvested at five stages of development. Freezedried kernels were separated into the husk tissues (lemma and palea), germ and germ‐free caryopsis. During maturation kernel weight increased about 21/2‐fold mainly due to the increase in the caryopsis. The husks of the immature kernel contained over 12% of the barley N but only 2% of the mature. Germ size and N contents increased so that germ N of the mature kernel was double that of the immature. The main changes in the proteins of the husks were increases in serine and glycine, and decreases in glutamic acid, proline and phenylalanine. In the caryopsis there were decreases in lysine, arginine, aspartic acid, tlueonine, glycirie, alanine and methionine; and increases in glutamic acid and proline. Husk proteins are characterized by relatively high concentrations of lysine, aspartic acid, serine, glycine, alanine and valine; the germ proteins are rich in arginine; and the caryopsis proteins contain the highest (among the barley components) concentrations of glutamic acid, proline, sulfur‐containing amino acids and phenylalanine.