太湖鱼中多不饱和脂肪酸及其与多氯联苯共摄入益害分析

Polyunsaturated fatty acids in fish from Taihu Lake and the associated risk of ingesting polychlorinated biphenyls

鱼体脂肪中含有丰富的n-3系多不饱和脂肪酸,但同时能富集有毒的持久性有机污染物.本文测定了太湖4种野生食肉性鱼类:刀鲚(Coilia ectenes taihuensis)、红鳍原鲌(Cultrichthys erythropterus)、似刺鳊鮈(Paracanthobrama guichenoti)和太湖新银鱼(Neosalanx taihuensis Chen)中的脂肪酸含量,分析了其脂肪酸组成,结果表明,这4种鱼体中脂肪酸以棕榈酸、油酸和DHA为主.通过多不饱和脂肪酸与饱和脂肪酸的比值(PUFA/SFA)及n-6/n-3PUFA比值分析了这些鱼类的营养价值,结果表明,这4种鱼类均具有较高的营养价值.由于环境持久性有机污染物多氯联苯可富积于鱼体脂肪中,摄入PUFAs的同时会摄入这类污染物.同时,对PUFAs中的有效成分EPA+DHA与多氯联苯共摄入时对人体的益害风险进行了评估,发现对于健康成人在达到EPA+DHA摄入要求下,食用这4种鱼带来的多不饱和脂肪酸与多氯联苯共摄入不会引起非致癌或致癌的健康风险.

Fish contain high levels of n-3 polyunsaturated fatty acids （PUFAs）, a desirable attribute for healthy eating. However, persistent organic pollutants often accumulate in fish. We measured the concentrations of fatty acids in four carnivorous fish： Coilia ectenes taihuensis, Cultrichthys erythropterus, Paracanthobrama guichenoti, and Neosalanx taihuensis Chen, collected from Taihu Lake, China. In addition, we evaluated the benefit-risk of co-ingestion of polychlorinated biphenyls and EPA＋DHA, the active components of PUFAs. Palmitic acid, oleic acid, and docosahexaenoic acid were the predominant fatty acids in all species. The nutritive value of all four species was high based on the ratio of polyunsaturated fatty acids to saturated fatty acids and n-6 to n-3 polyunsaturated fatty acids （n-6/n-3 PUFA）. Our data suggest that ingestion of the recommended 250 mg EPA＋DHA intake per day for a healthy adult via the consumption of any of the four species would likely not result in the risk of cancer.