植物油中脂肪酸不同定量方法的比较分析

Comparative analysis of different quantitative methods of fatty acids in vegetable oil

比较峰面积归一化法与标准曲线法两种方法分析植物油中脂肪酸百分比含量的差异。利用气相色谱-质谱联用仪(GC-MS)检测10种市售食用植物油中的8种主要脂肪酸,峰面积归一化法和标准曲线法计算脂肪酸的百分比含量。结果表明,标准曲线法与峰面积归一化法相比,肉豆蔻酸、棕榈酸、十七烷酸、硬脂酸和棕榈油酸所占的百分比升高,而油酸、亚油酸和亚麻酸比例降低;饱和脂肪酸比例升高,不饱和脂肪酸百分比降低。利用峰面积归一化法计算植物油中脂肪酸百分比时,降低了饱和脂肪酸比例,升高了不饱和脂肪酸比例,可能对健康有潜在的不利影响。建议使用标准曲线法计算不同植物油中脂肪酸的百分比。

The differences between the normalized peak area method(NPA)and the standard curve analysis method(SCA)in the proportion of fatty acids in vegetable oils were compared in this study.Eight fatty acids in 10 commercially available edible vegetable oils were detected by GC-MS,and the percentage of fatty acids was calculated both by NPA and SCA.The results showed that the percentage of myristic acid,palmitic acid,heptadecanoic acid,stearic acid and palmitoleic acid increased by SCA compared with NPA,while the proportions of oleic acid,linoleic acid and linolenic acid decreased.The proportion of saturated fatty acids increased,and the percentage of unsaturated fatty acids decreased.Compared with SCA,NPA reduced the proportion of saturated fatty acids and overestimated the intake of unsaturated fatty acids,which may have potential adverse effects to health.The standard curve method is recommended to calculate the percentage of fatty acids in different vegetable oils.