气相色谱法测定不同水域刀鲚肉中脂肪酸含量

Analysis of fatty acid profile in the meat of three kinds of Coilia ectenes by gas chromatography

对刀鲚肉中脂肪酸含量气相色谱分析的甲酯化方法：硫酸-甲醇法、氢氧化钾-甲醇法和三氟化硼-甲醇法进行了选择,采用内标法对长江刀鲚、东海刀鲚和黄河刀鲚肉中脂肪酸进行了定量分析。方法的精密度良好,RSD值〈3%,回收率在93%-108%之间（n=3）。三种刀鲚肉中检测到29种脂肪酸,共有脂肪酸27种,其中东海刀鲚肉中未能检测到C10∶0和C24∶0。三种刀鲚肉的多不饱和脂肪酸（PUFA）与饱和脂肪酸（SFA）的比值P∶S值均高于0.4,长江刀鲚、东海刀鲚和黄河刀鲚肉的AI值分别为0.47、0.38、0.40。单不饱和脂肪酸含量高,占脂肪酸总量的50%以上,其中C16∶1和C18∶1n9c两种分别对风味和营养有重要作用的脂肪酸含量丰富。三种刀鲚脂肪酸含量存在显著差异（p〈0.05）。东海刀鲚中DHA含量显著（p〈0.05）高于长江刀鲚和黄河刀鲚。从脂肪酸含量及组成来看,东海刀鲚的营养价值高于其他两种刀鲚,而从C16∶1和C18∶0的含量上来看,长江刀鲚的风味则更胜一筹。

The different methods of fatty acids methyl esterification （HSO4-methanol, KOH-methanol, BF3-methanol method） were compared in this study in order to establish the optimum for analysing by gas chromatography. The fatty acids contents of Yangtze river-coilia,East sea-coilia and Yellow river-coilia were determined using internal standard method. The recoveries of the GC method were 93%-108% （n=3）. 29 kinds of fatty acids were identified in three kinds of coilia ectenes,of which 27 kinds were identified in both three kinds. The P：S values were more than 0.4 in three kinds of coilia ectenes,and the AI value was 0.47,0.38 and 0.40,respectively. The content of monounsaturated fatty acids（MUFA） accounted for more than 50% of the total fatty acids. C16：1 and C18：1n9c,which had significant effects respectively on flavor and nutrition,were abundant in three kinds of coilia ectenes. There were significant differences（p〈0.05） in most fatty acid contents of the three kinds of Coilia ectenes. The DHA content of East sea-coilia was significantly higher（p〈0.05） than that of Yangtze river-coilia and Yellow river-coilia. The East sea-coilia had comparatively higher nutritive value while the Yangtze rivercoilia had better flavor base on the fattv acids content and profile.