Kinds of Free Amino Acid in Rice Kernel

Abstract

The relation between rice kernels and changes of free amino acid in them with elapsed storing-period was investigated by mean of paper partition chromatography. For paper chromatography, Toyo filter paper No. 51 and 80% phenol water solution chosen as solvent was used and also the developed spots were identified by Rf value determined previously with Azinomoto K. K.'s pure reagent. Ordinarily it was diclosed that free amino acid detected in extracts from flesh brown rice (Hervest;1960, Variety Norin No. 17.) were as follows; aspartic acid, glutamic acid, glycine, histidine, alanine and valine and that the decreases of above mentioned amino acids were generally found in older nice (Havest; 1957-1959), though both aspartrc acid and glutamic acid decreased more clearly than the others and the decrease of alanine was not shown clearly on map. In later stage of storage, however, now amino acids product by the degeneration of the proteins had been founded and presumably these amino acids were composed of asparagine, cystine and leucine. It was suggested that gradtial loss of the reserves in brown rice grain itself was caused for living such as maintenance of germinating ability, in the course of time after harvest and there was a general tendency that greater loss was observed in aspartic acid and glutamic acid included the brown rice and increase in leucine, asparagine and cystine was observed from unknown factors. It seems to be absolutely necessary to investigate glutamic acid, glycine and alanine as important amino acids included in white rice for the research and discussion on rice taste.