Polyunsaturated fatty acids and nutritional quality of five freshwater fish species cultivated in the western region of Santa Catarina, Brazil

Abstract There is a paucity of information about the chemical composition of commercially important freshwater fish species (Nile tilapia, bighead carp, grass carp, common carp and silver carp) cultivated in the western region of Santa Catarina, Brazil. This study determined the moisture, ash, protein and lipid contents and the fatty acid composition, as well as the nutritional quality of the lipids in fillets of these five freshwater fish species. Moisture was the most prominent fish component (74.7%-81.7%), followed by protein (15.8%-18.8%) and lipids (0.4%-8.2%). Saturated palmitic acid (90-1740 mg/100 g) and monounsaturated oleic acid (70-2260 mg/100 g) were the major fatty acids found in all the fish species. The grass and common carps and Nile tilapia (caged) had high contents of γ-linolenic acid (GLA), with an average of 536 mg/100 g. Bighead carp was the richest source of ω-3 PUFA, mainly eicosapentaenoic (EPA, 400 mg/100 g) and docosahexaenoic (DHA, 620 mg/100 g) acids, and had the highest ω-3/ω-6 ratio of 6.11. The nutritional evaluation of the fatty acid profile indicated that average values were: atherogenicity index (AI) ~0.59, thrombogenicity index (TI) ~0.82, hypocholesterolemic/hypercholesterolemic ratio (H/H ~1.98), polyunsaturated/saturated ratio (P/S) ~0.43 and ω-3/ω-6 ratio ~2.18, values suggesting that the consumption of these freshwater fish species could be of benefit to human health.

摘要 目前针对巴西圣卡塔琳娜州西部养殖的具有商业价值的淡水鱼类（尼罗罗非鱼、鳙鱼、草鱼、鲤、鲢鱼）的化学成分相关信息较为匮乏。本研究测定了上述五种淡水鱼鱼肉的水分、灰分、蛋白质、脂质含量，脂肪酸组成，以及脂质的营养品质。结果显示，水分是鱼肉中占比最高的组分（74.7%~81.7%），其次为蛋白质（15.8%~18.8%）与脂质（0.4%~8.2%）。饱和脂肪酸中的棕榈酸（90~1740 mg/100g）与单不饱和脂肪酸中的油酸（70~2260 mg/100g）为所有受试鱼类的主要脂肪酸。草鱼、鲤以及笼养尼罗罗非鱼的γ-亚麻酸（γ-linolenic acid, GLA）含量较高，平均可达536 mg/100g。鳙鱼是ω-3多不饱和脂肪酸（ω-3 PUFA）的最丰富来源，其主要成分为二十碳五烯酸（eicosapentaenoic acid, EPA，400 mg/100g）与二十二碳六烯酸（docosahexaenoic acid, DHA，620 mg/100g），且ω-3/ω-6比值最高，达6.11。对该脂肪酸谱进行的营养评价结果显示，各项指标的平均值分别为：致动脉粥样硬化指数（atherogenicity index, AI）约0.59、血栓形成指数（thrombogenicity index, TI）约0.82、低胆固醇/高胆固醇比值（hypocholesterolemic/hypercholesterolemic ratio, H/H）约1.98、多不饱和/饱和脂肪酸比值（polyunsaturated/saturated ratio, P/S）约0.43，以及ω-3/ω-6比值约2.18；上述指标表明，食用这五类淡水鱼类对人体健康有益。