Total lipid nutritional quality of the adipose tissue from the orbital cavity in Nile tilapia from continental aquaculture

ABSTRACT. This study aimed to determine the fatty acid composition and nutritional quality indexes of total lipids in adipose tissue from the orbital cavity of Nile tilapia from continental aquaculture in Paraiba State, Brazil. The tilapias were captured in six fish farms, and after slaughtering and bleeding, the adipose tissue from the orbital cavity was reserved, frozen and lyophilized for analysis of fatty acid composition by gas chromatography. By decreasing order, oleic, palmitic, linoleic, stearic, and palmitoleic acids were the most abundant ones. Monounsaturated fatty acids were the most prominent group in orbital cavity adipose tissue, where as polyunsaturated fatty acids were most abundant in the diet, with a percentage of linolenic acid ranging from 32.99 to 37.57%. Nutritional quality indexes of lipids varied from 0.491 to 0.575 for Atherogenicity Index, 0.543 to 0.741 for Thrombogenicity Index, and from 1.918 to 2.176 regarding the ratio of hypocholesterolemic/hypercholesterolemic. According to the composition of fatty acids and the nutritional quality of total lipids, the use of this byproduct can be recommended for human consumption or to elaborate products for animal intake.

摘要。本研究旨在测定巴西帕拉伊巴州内陆水产养殖业的尼罗罗非鱼（Nile tilapia）眼眶脂肪组织（orbital cavity adipose tissue）中总脂质的脂肪酸组成与营养品质指标。研究人员从6家水产养殖场捕获罗非鱼，经屠宰放血后留存眼眶脂肪组织，经冷冻、冷冻干燥处理后，采用气相色谱法（gas chromatography）分析其脂肪酸组成。按含量由高到低排序，油酸（oleic acid）、棕榈酸（palmitic acid）、亚油酸（linoleic acid）、硬脂酸（stearic acid）及棕榈油酸（palmitoleic acid）为含量最高的五类脂肪酸。眼眶脂肪组织中以单不饱和脂肪酸为优势组分，而日粮中多不饱和脂肪酸占比最高，其中亚麻酸（linolenic acid）的占比范围为32.99%~37.57%。脂质的各项营养品质指标如下：致动脉粥样硬化指数（Atherogenicity Index）范围为0.491~0.575，致血栓形成指数（Thrombogenicity Index）范围为0.543~0.741，低胆固醇/高胆固醇比值范围为1.918~2.176。基于脂肪酸组成与总脂质的营养品质，该副产物可推荐用于人类食用或开发为动物饲喂用产品。