Abstract
As a fundamental study on the efficient utilization of marine fish resources as foodstuffs, the white muscles of nine species of newly exploited fish were analyzed for proximate composition, non-protein nitrogenous constituents and amino acid composition of proteins. The results obtained are summarized as follows.
1) The content of crude fat in pelagic armorhead Pentaceros richardsoni was noticeably high, amounting to 16.3%.
2) The muscle extracts of barracouta Thyrsites atun, silver warehou Seriolella maculata and warehou S. brama were characterized by the presence of large amount of free histidine, and those of southern blue whiting Micromesistius australis and New Zealand whiptail Macruronus novaezelandidae by the presence of large amount of anserine and small amount of 1-methylhistidine. The muscles of pelagic armorhead and southern blue whiting were found to contain more than 100mg of taurine/100g of the muscle.
3) Among nucleotides and related compounds, IMP was dominant in all the fish analyzed, and its content exceeded 200mg/100g of the muscle in barracouta, silver warehou and warehou.
4) Trimethylamine oxide and creatine constituted important parts of nitrogenous extractives in the muscles of these fish. Especially, the content of trimethylamine oxide in look-down dory Cyttus traversi, kingklip Genypterus blacodes and New Zealand hake Merluccius australis, and that of creatine in barracouta, silver warehou and warehou were very high.
5) The amino acid compositions of muscle proteins of these fish closely resembled each other, and the levels of amino acids were mostly within the range of the values reported on the common edible fish in Japan. These results suggest that the muscles of the analyzed fish are excellent protein sources as those of the common fish.
