鄱阳湖野生鱼类脂肪酸含量的比较研究

Comparison of Fatty Acids in Wild Freshwater Fish of the Poyang Lake

通过研究鄱阳湖野生淡水鱼类脂肪酸的含量,了解鄱阳湖鱼类中饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸(PUFA)的含量和构成比。鱼肌肉用氯仿甲醇溶液提取脂肪,碱法甲酯化后用气相色谱分析。结果显示:鱼肌肉中的PUFA的含量随鱼类品种的不同有较大的差别,范围为18.65%～43.07%;二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)的含量也变化较大,其中黄颡鱼的DHA含量最高,可达10.72%,而鲹鲦的EPA含量则是所测鱼类中最高的,达4.61%。其中n-3系不饱和脂肪酸与n-6系不饱和脂肪酸的比例也相差悬殊,从1:0.7到1:2.5不等。不同科目的鱼,在C22:4n-6、C22:5n-3(DPA)含量上有显著性差异。不同生活习性的鱼,其共轭亚油酸(CLA)、C20:4n-6、C22:2n-6、C22:4n-6、C22:5n-3、C22:6n-3(DHA)均存在显著性差异。研究结果表明鄱阳湖水域中,鱼肌肉的多不饱和脂肪酸与鱼的生活习性如生活在不同的水层和食性等有较大关系,鱼的遗传因素与脂肪酸比例和含量也有一定关系。

The aim of this study was to explore the content of fatty acids （FA） in wild freshwater fish in the Poyang Lake. The muscles of fish were collected to extract lipids using methanol and chloroform. Lipids were methylated with the base-catalyzed transesterification method and analyzed by C,C. The results demonstrated that the content of PUFA varied with the kinds of fishes from 18.65% to 3.07%. The DHA content was 10.72% in yellow cartfish, the EPA content was 4.61% in scad. The ratio of n-3 PUFA/n-6 PUFA was significantly different, from 1：0.7 to 1：2.5. The contents of C22：4 n-6 and C22：5 n-3（DPA）had a significant difference in fish of different subject. The content of CLA, C20：4 n-6, C22：2 n-6,C22：4 n-6, C22：5 n-3, C22：6 n-3（DPA） and C22：6 n-3（DHA） had a significant difference in fish of different life habitual. The results indicated also that the PUFA of fish muscles had relations with the life habit of fish such as the height of water and feeding habit in the Poyang Lake.