Characterization and authentication of four important edible oils using free phytosterol profiles established by GC-GC-TOF/MS

摘要

Adulteration of high-price edible oils has become a focus of attention and a tough problem in food trade and consumption all over the world. Therefore, there is a great demand for detecting oil adulteration to protect interests and rights of customers and safeguard their health. In this study, free phytosterol profiles of peanut, soybean, rapeseed, and sunflower seed oils were established by SPE-multidimensional gas chromatography coupled with time-of-flight mass spectrometry (GC-GC-TOF/MS) and employed to classify the four edible oils with the help of unsupervised (principal component analysis and hierarchical clustering analysis) and supervised (random forests) multivariate statistical methods. The results indicated that free phytosterol profiles of edible oils could help classify the four edible oils into four groups completely, and therefore, could be used as important markers of the oils studied. Moreover, a simulated data test revealed that free phytosterol profiles could also be used to detect adulteration of peanut oil with 5% soybean oil, which was simulated by the Monte Carlo method.