Seasonal Variations Chemical Constituents of Yellowtail Muscle-II.

Abstract

The principal components of nitrogenous extractives were investigated, mainly from a food chemical point of view, using the dorsal and ventral muscles of 4 groups of yellow-tail, Seriola quinqueradiata, i.e. “cultured-young”, “cultured-adult”, ‘wild-young, and “wild-adult”. Results obtained were as follows.(1) The contents of extractive nitrogen and free histidine were higher in the dorsal muscle of “wild-young” than in that of “cultured-young”, and the content of trimethylamine oxide was higher in “wild-adult” than in “cultured-adult”. There was no difference in creatine content among the 4 groups.(2) A marked seasonal variation was observed in the trimethylamine oxide content of “young” groups, which decreased in summer and increased in late autumn.(3) Of the free amino acids determined, histidine was the most abundant in every group. Taurine, lysine, glutamic acid and alanine were present in moderate amounts and the other amino acids, in small amounts. No marked difference among the groups was observed in the distribution pattern of these amino acids excepting histidine, taurine and lysine.(4) A taste test was undertaken on hot-water extracts prepared from the muscles of these groups, and the “wild” groups were found to be more tasty than “cultured” groups.