鳐鱼肝油的制备及其脂肪酸组成分析

Preparation of liver oil from skate and analysis of fatty acid composition

本研究采用冷冻-解冻的方法提取鳐鱼肝粗脂肪油,并利用响应面法优化了精炼过程中影响较大的脱酸工艺,分析了精炼后鳐鱼肝油的理化性质、脂肪酸组成及含量变化。结果表明:使用5%(质量分数)脱胶剂脱胶,20%(质量分数)氢氧化钠、75℃加热20 min进行脱酸,8%(质量分数)活性白土脱色,以及减压蒸馏(60 r/min,40℃)60 min脱臭的鳐鱼肝油精炼工艺为最优精炼工艺条件,所得精炼鳐鱼肝油呈色及各项理化性质均符合国家一级鱼油标准。脂肪酸组成与粗鳐鱼肝油、鳕鱼肝油以及鲨鱼肝油无明显差别,均含有C14~C22脂肪酸23种,但在含量上存在一定差别,其中精炼鳐鱼肝油中EPA含量为8.65%,低于粗鳐鱼肝油(10.17%),远高于鲨鱼肝油(2.74%),约等于鳕鱼肝油(8.78%)。精炼鳐鱼肝油中DHA含量则为最高,为15.04%。

This study adopted freezing-unfreezing method to extract the crude fatty oil from the livers of skate and response surface methodology to optimize the deacidification during refining process and then analyzed the physical and chemical properties,fatty acid composition and content changes of skate liver oil.The result shows that the optimal process conditions were as follows:degumming agent with 5%oil weight,deacidification by heating 20%sodium hydroxide of oil weight at 75℃for 20 min,decolorizing with 8%activated clay of oil weight and deodorization by vacuum distillation for 60 min at 40℃,60 r/min.The color and physical and chemical properties of the refined skate liver oil obtained under these conditions were in line with the level I of national standard Fish oil.Its fatty acid composition has no obvious difference from that of crude skate liver oil,cod liver oil or shark liver oil,which contain 23 kinds of C14~C22 fatty acids.However,there were some differences in contents.The EPA content of refined skate liver oil was 8.65%.It was lower than 10.17%of crude skate liver oil but much higher than 2.74%of shark liver oil and approximately equal to 8.78%of cod liver oil.However,the DHA content of refined skate liver oil was the highest at 15.04%.