基于特征脂肪酸变化对花生油掺伪快速鉴别方法研究

Rapid identification of adulteration in peanut oil based on the changes of characteristic fatty acid

该实验采用近红外光谱与气相色谱相结合,通过对特征脂肪酸的含量变化,开展快速鉴别花生油掺伪的研究。以花生油中掺入不同比例菜籽油、棉籽油及大豆油作为掺伪样品,气相色谱法测得掺伪油样棕榈酸、硬脂酸、油酸、亚油酸和花生酸5种特征脂肪酸含量,使用近红外光谱测定其R—H基团在1170、1205、1395、1415 nm特征峰波长的变化,利用Unscrambler 10.4软件通过偏最小二乘判别法对脂肪酸含量与近红外光谱图峰位相拟合,建立一元回归线性方程。结果表明,掺伪花生油5种特征脂肪酸均有响应,棕榈酸对应的近红外光谱模型较好,校正集相关系数为0.997,校正均方根误差为0.014、交叉验证均方根误差为0.018。通过多种花生油进行验证,预测模型准确,对快速无损检测花生油具有重要意义。

In this experiment,near-infrared spectroscopy and gas chromatography were used to quickly identify the adulteration of peanut oil through the change of the content of characteristic fatty acids.Peanut oil adulterated with different proportions of rapeseed oil,cottonseed oil,and soybean oil was as adulterated samples.The contents of five characteristic fatty acids of palmitic acid,stearic acid,oleic acid,linoleic acid,and arachidonic acid in adulterated peanut oil samples were measured by gas chromatography.The characteristic peak wavelengths of changes of R—H groups at 1170,1205,1395,and 1415 nm were measured by near-infrared spectroscopy.The fatty acid was matched with the peak position of near-infrared spectroscopy spectrum by partial least squares discriminant method using Unscrambler 10.4 software.A single regression linear equation was established.Results showed that the five characteristic fatty acids of adulterated peanut oil all responded and the corresponding near-infrared spectral model of palmitic acid was better,with R^(2)c of 0.997,RMSEC of 0.014,and RMSECV of 0.018.The prediction model is validated by a variety of peanut oils and it is accurate,which is of great significance for rapid non-destructive testing of peanut oil.