大豆油中掺伪棕榈油的检测方法研究

Determination of palm oil adulterated in soybean oil

采用气相色谱法对72份纯品大豆油和70份棕榈油的脂肪酸组成进行测定,并进行了组分间的相关性分析。结果表明,大豆油和棕榈油中亚油酸(C18∶2)平均值分别为55.6%和10.7%;不饱和脂肪酸(C18∶1+C18∶2+C18∶3)含量最稳定,平均值分别为86.0%和52.0%;C18∶1+C18∶2值较稳定,平均值分别为77.7%和51.7%。对10份掺伪模拟样品进行了测定,其定量分析结果的相对标准偏差(RSD)均小于5%,利用这3项指标可对大豆油中掺伪棕榈油的含量进行多元定量计算。

The fatty acid compositions of 72 pure soybean oils and 70 pure palm oils were analyzed by gas chromatography, the correlation analysis between fatty acids was made as well. Results showed that the content of linoleic acid in soybean oil and palm oil had slight variation,with the average being of 55.6% of soybean oil and 10.7% of palm oil. The contents of unsaturated fatty acids were the stablest,with the average being of 86.0% of soybean oil and 52.0% of palm oil. Oleic and linoleic acid together constitu- ted 77.7% of soybean oil and 51.7% of palm oil ,which were relatively stable. Ten adulterated soybean oils were determined and their relative standard deviations of quantitative analysis were less than 5%, according to the three indexes, the content of palm oil adulterated in soybean oil could be calculated by multinomial quantitative method.