胰脂肪酶法测定食用油甘油三酯中脂肪酸的位置分布.pdfVIP

544 2008, Vol. 29, No. 11 食品科学 ※分析检测 1,2,3 1,2,3, 1,2,3 1,2,3 袁小武 ，邓泽元 * ，李 静 ，范亚苇 (1.南昌大学 食品科学与技术国家重点实验室，江西 南昌 330047 ；2.南昌大学高等研究院，江西南昌 330047 ； 3.南昌大学食品科学与工程系，江西南昌 330047) ：本实验采用sn-1,3 位专一性脂肪酶(胰脂肪酶) 对甘油三酯进行作用，专一水解位于sn-1 、sn-3 的酯键， 将该两个位置上的脂肪酸游离出来，通过薄层层析分离得到游离脂肪酸和sn-2- 甘油一酯，甲酯化作用后用气相色 谱法对脂肪酸进行测定。用该方法对花生油、大豆油、玉米油、菜籽油、茶油进行了测定。结果表明，这几 种油不饱和脂肪酸含量达到了80%，在sn-2 位上分布更是超过了90% ，而少量的饱和脂肪酸则主要是分布在sn-1, 3 位上。 ：脂肪酸；胰脂肪酶；T L C 分离；气相色谱 Stereospecific Analysis of Fatty Acids in Triacylglycerols of Several Edible Oils with Pancreatic Lipase Hydrolysis YUAN Xiao-wu 1,2,3 ，DENG Ze-yuan 1,2,3,*，LI Jing1,2,3 ，FAN Ya-wei 1,2,3 (1.State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China； 2.Institute for Advanced Study, Nanchang University, Nanchang 330047, China ； 3.Department of Food Science and Engineering, Nanchang University, Nanchang 330047, China) Abstract：In this study, the purified triacylglycerols (TAG) of some edible oils were subjected to stereospecific hydrolysis by an sn-1, 3-specific lipase (pancreatic lipase) which cleaves selectively the sn-1 and sn-3 position ester bonds of TAG yielding to 2-monoglycerides (2-MAG) and free fatty acids (FFA). After lipase hydrolysis, the released free fatty acids and 2-MAG were isolated by thin-layer chromatography (TLC) and were converted to fatty acid methyl esters, and then analyzed by gas-liquid chromatography. The method was applied for stereospecific analyses of peanut, soyabean, maize, rapeseed and camellia oil. And the fatty acids in the TAG were also determined. Results showed that vegetable oils are made up of unsaturated fatty acid