| Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1993: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Research Abstract |
It is said that there is the best season and the worst season for eating fises and shellfishes depending on species. Generally, the best season coincides the season when the lipid content of the fish becomes highest before spawinig. Shellfish may not be related to the lipid content, because they have only a small amount of lipid, for example, the lipid content of abalone is only 0.4%. Therefore seasonal variation in another chemical components may be related to the best season of the reputation. In addition, not only chemical components but also textural properties should be considered since the texture is another important factor to determine the preferance of food. The objective of the present study was to determine changes in the chemical composition and texture of abalone and three kinds fish species in relation to their seasonal variations.
Seasonal changes in AMP,total free amino acid, total oligopeptide in the abalone meat were analyzed and their levels were found to be higher in summer and lower in winter. In any seasons, the most abundant free amino acid was Tau followed by Arg, Gly, Gln, Glu. The largest peptide-bound amino acid was Glx. The breaking stress values of the meat were low in summer and high in winter, indicating that the summer abalone is tenderer than the winter abalone. These studies suggest that the summer abalone is preferable because flavor components are richer and the texture was tenderer in summer than in any other seasons.
From the cultured fish, three kinds of species are selected. They are yellow-tail which is the species of high lipid content, red sea bream which is the species of intermediate lipid content and flounder which is the species of low lipid content. The flounder did not differ in lipid content between wild and cultured, and did not show, seasonal variations. Another two species, yellow-tail and red seabream, seemed to show the same seasonal variation between wild and cultured though the sample size was limited.
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