中国市售桶装植物油脂肪酸的研究

目的对市售桶装植物油中脂肪酸进行分析,探讨其组分及含量特点。通过植物油中各类脂肪酸比例的特点,分析脂肪酸特征。方法从北京、云南、浙江、湖南、河南、哈尔滨、江苏、甘肃8个地区,选取市场普遍销售的或各地自产的品牌桶装植物油,共计8个品种,每个样品采集2个不同批号。对植物油脂进行皂化和甲酯化后,利用岛津GC2014气相色谱仪对样品进行气相色谱分析。结果市售桶装植物油主要以棕榈酸、油酸、亚油酸和α-亚麻酸为主,反式脂肪酸的平均含量为1.05g/100g。植物油的饱和脂肪酸∶单不饱和脂肪酸∶多不饱和脂肪酸的比值范围为1∶1.6～9.4∶0.9～7.4;多不饱和脂肪酸中n-6/n-3的比值范围为0.37～289.5∶1。结论市售桶装植物油反式脂肪酸含量低,但脂肪酸组成比例大多不符合中国营养学会提出的标准,并且多数缺乏n-3多不饱和脂肪酸。

Composition of fatty acid in commercially available bottled vegetable oil

Objective To analyze the fatty acid composition of commercially available bottled vegetable oil,and to explore its characteristic composition and content and the proportion of specific fatty acids.Methods A total of eight varieties of bottled vegetable oil which are popular in use or famous with local brand from eight districts of Beijing,Yunnan,Zhejiang,Hunan,Henan,Harbin,Jiangsu and Gansu were collected,and selected two different batches for each variety.After being saponified and methyl esterified,the fatty acids of vegetable oil samples were analyzed by Shimadzu GC2014 gas chromatography.Results The commercially available bottled vegetable oils were mainly consisted of palmitic acid,oleic acid,linoleic acid and α-linolenic acid.The average content of trans fatty acids was 1.05g/100g.The ratio of saturated fatty acids∶monounsaturated fatty acids∶polyunsaturated fatty acid(S∶M∶P) of vegetable oil samples was in the range of 1∶1.6-9.4∶0.9-7.4;the ratio of polyunsaturated fatty acid n-6:n-3 was in the range of 0.37-289.5∶1.Conclusion The content of trans fatty acid in commercially available bottled vegetable oil was low,however,most of the proportion of fatty acid did not meet the standards suggested by the Chinese Nutrition Society,and most of vegetable oils are lack of n-3 polyunsaturated fatty acids.