大青鲨和镰状真鲨软骨中部分营养成分分析与安全评价

Nutrition Analysis and Safety Evaluation on the Cartilage of Prionace glauca and Carcharhinus falciformis

为科学开发利用鲨(Selachimorpha)软骨中的生理活性成分,同时初步掌握鲨软骨的重金属含量情况,本研究采用国标方法分别测定了大青鲨(Prionace glauca)和镰状真鲨(Carcharhinus falciformis)两种鲨软骨的游离氨基酸、脂肪酸、硫酸软骨素和胶原蛋白等营养成分及重金属的含量.结果显示,大青鲨和镰状真鲨软骨中硫酸软骨素含量分别为18.69和4.82 mg/g,胶原蛋白含量分别为4.19和6.77 g/100g.大青鲨和镰状真鲨软骨中16种游离氨基酸的总含量分别为11.09和14.30 g/100g,其中甘氨酸(Gly)含量最高,组氨酸(His)含量最低;必需氨基酸有7种,分别占氨基酸总量的26.15%和27.06%;氨基酸评分(AAS)、化学评分(CS)和必需氨基酸指数(EAAI)结果显示,大青鲨和镰状真鲨软骨的氨基酸评分均比较低,营养品质相近,蛋氨酸+胱氨酸(Met+Cys)是第一限制性氨基酸,苯丙氨酸+酪氨酸(Phe+Tyr)是第二限制性氨基酸.大青鲨和镰状真鲨软骨中共检出16种游离脂肪酸,其中含量较为丰富的是C16:0、C18:0、C18:1n9-c、C24:1n-9以及C22:6n-3(DHA),占脂肪酸总量的73.1%(大青鲨)和76.0%(镰状真鲨),且不饱和脂肪酸含量均高于饱和脂肪酸.两种鲨软骨中铅、镉、甲基汞和无机砷的含量均远低于食品安全国家标准中污染物的限量要求.研究认为,大青鲨和镰状真鲨软骨中均含有丰富的硫酸软骨素和胶原蛋白,大青鲨的硫酸软骨素含量高于镰状真鲨,而单种氨基酸、总脂肪酸和胶原蛋白的含量均低于镰状真鲨;两种鲨软骨中的重金属含量均较低.

In order to scientifically develop and apply the physiological active ingredients in the cartilage of Selachimorpha and preliminarily grasp its heavy metal contents, the free amino acids, fatty acids and heavy metals in the cartilage of two species of shark, Prionace glauca and Carcharhinus falciformis, were determined by the national standard method in the study. The results showed that there was abundant chondroitin sulfate and collagen in the cartilage of both Prionace glauca and Carcharhinus falciformis. The contents of chondroitin sulfate were 18.69 mg/g and 4.82 mg/g, respectively, and the collagen were 4.19 g/100 g and 6.77 g/100 g, respectively. Sixteen kinds of free amino acids were detected in both Prionace glauca and Carcharhinus falciformis cartilage with the total content of 11.09 and 14.30 g/100 g, respectively. Among them, glycine(Gly) content was the highest, and histidine(His) was the lowest. There were 7 essential amino acids, accounting for 26.15% and 27.06% of the total amino acids, respectively. The AAS, CS and EAAI evaluation scores showed that the amino acid nutritional quality of both Prionace glauca and Carcharhinus falciformis cartilage were similar and relatively low. Methionine + cystine(Met+Cys) was the first limiting amino acid, and phenylalanine + tyrosine(Phe+Tyr) belonged to the second one. A total of 16 free fatty acids were detected, among which C16∶0, C18∶0, C18∶1 n9-c, C24∶1 n-9 and DHA were the most abundant, accounting for 73.1%(Prionace glauca) and 76.0%(Carcharhinus falciformis) of the total fatty acids. Moreover, the contents of unsaturated fatty acids were higher than that of saturated fatty acids. The contents of lead, cadmium, methyl mercury and inorganic arsenic in cartilage of two kinds of Selachimorpha were far lower than the pollutants limit in the national food safety standards. In general, the content of chondroitin sulfate in Prionace glauca cartilage were higher than that in Carcharhinus falciformis, while the content of collagen protein, every amino acid and total fatty acid was all lower than those in Carcharhinus falciformis. The heavy metal contents were low in the cartilage of both Prionace glauca and Carcharhinus falciformis.