牦牛酥油磷脂提取工艺研究及脂肪酸成分分析

Study on the process of yak butter phospholipids and analysis of fatty acid composition

以青海牦牛酥油为原料,正己烷为提取溶剂,磷脂得率和纯度为考察指标,通过单因素试验以及正交试验,探讨液固比、提取时间、提取温度和丙酮沉淀时间4个因素对牦牛白酥油(冬季)和黄酥油(夏季)磷脂提取的影响。确定黄色牦牛酥油最优磷脂提取的工艺为:液固比6mL/g,提取时间60min,丙酮沉淀时间25h,提取温度55℃,在此工艺条件下粗磷脂得率为6.74%,纯度为62.96%;白酥油提取温度45℃,得率为4.97%,纯度为58.09%。原料及产物通过气相色谱质谱联用分析了脂肪酸组成,结果表明,牦牛酥油中检出36种脂肪酸,其中饱和脂肪酸26种,不饱和脂肪酸10种;酥油磷脂中共检测出29种脂肪酸,其中饱和脂肪酸24种,不饱和脂肪酸5种。牦牛酥油与酥油磷脂脂肪酸组成以及含量差别较大,酥油磷脂中支链脂肪酸、单不饱和脂肪酸和中链脂肪酸含量显著低于牦牛酥油;牦牛酥油不饱和脂肪酸含量是酥油磷脂的5倍以上,并且牦牛酥油中含有的多种不饱和脂肪酸(如EPA、DHA等)在酥油磷脂中并未检测出。

Taking Qinghai yak ghee as raw material, hexane is the extraction solvent, and the phospholipid yield and purity were used.The effects of four factors of liquid- solid ratio, extraction time, extraction temperature and acetone precipitation time on the extraction of white yak butter (winter) and yellow yak butter (summer)phospholipids were discussed by single factor experiment and orthogonal experiment.The optimal process for extracting phospholipids from yellow yak butter were determined as follows: liquid- solid ratio 6 mL/g, extraction time 60min, acetone precipitation time 25 h, extraction temperature 55℃. The yield of crude phospholipids was 6.74% and the purity was 62.96%;The white yak butter extraction temperature was 45 ℃, the yield was 4.97%, and the purity was 58.09%. The fatty acid composition was analyzed by gas chromatography-mass spectrometry, The results showed that 36 fatty acids were detected in yak butter, including 26 kinds of saturated fatty acids, 10 kinds of unsaturated fatty acids;A total of 29 fatty acids were detected in phospholipids, including 24 kinds of saturated fatty acids, and 5 kinds of unsaturated fatty acids. The composition and content of fatty acids in yak butter and ghee phospholipids are quite different,the content of branched chain fatty acids, monounsaturated fatty acids and medium chain fatty acids in butter oil phospholipids is significantly lower than that of yak butter;The content of unsaturated fatty acids in yak butter was more than five times that of ghee phospholipids,Moreover, various unsaturated fatty acids (such as EPA, DHA, etc.) contained in yak butter are not detected in ghee phospholipids.