Seasonal variations in marine foods

据说，根据种类的不同，吃鱼和贝类有最好的季节和最坏的季节。一般来说，最佳的季节是产卵前鱼体脂肪含量最高的季节。贝类可能与脂质含量无关，因为它们只有少量的脂质，例如鲍鱼的脂质含量仅为0.4%。因此，季节性变化中的另一种化学成分可能与最佳季节的声誉有关。此外，不仅要考虑化学成分，还要考虑质构特性，因为质构是决定食品偏好的另一个重要因素。为研究鲍鱼及3种鱼类化学成分和质构的季节变化，分析了鲍鱼肉中AMP、总游离氨基酸和总寡肽含量的季节变化，发现其含量夏季较高，冬季较低。在任何季节，最丰富的游离氨基酸是Tau，其次是Arg，Gly，Gln，Glu。最大的肽结合氨基酸是Glx。鲍肉的断裂应力值夏季较低，冬季较高，表明夏鲍的断裂应力值比冬鲍的断裂应力值低。这些研究表明，夏季鲍鱼的风味成分较丰富，质地较好，是较佳的养殖品种。它们是高脂肪含量的黄尾、中等脂肪含量的真鲷和低脂肪含量的比目鱼。比目鱼没有不同的野生和养殖之间的脂质含量，并没有显示，季节性变化。另外两个物种，黄尾和红海鸟，似乎表现出相同的季节变化之间的野生和养殖，但样本量有限。

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.