Optimization of Headspace SPME GC × GC-TOF/MS Analysis of Volatile Organic Compounds in Edible Oils by Central Composite Design for Adulteration Detection of Edible Oil

Abstract

Volatile flavor components are critical to edible oils and influence consumption choice. Meanwhile, volatile organic compounds (VOCs) in edible oils are also potential biomarkers to detect adulterated products. However, VOCs are usually complex, unstable, and easily influenced by oil processing and even analysis conditions. Here, we report headspace solid-phase microextraction for comprehensive two-dimensional gas chromatography mass spectrometric analysis of VOCs in edible oils as being optimized and validated using central composite design (CCD). The results indicated that the optimal extraction conditions are as follows: SPE column of divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), equilibration time of 10.3 min, and extraction time of 19.6 min at 120 °C. This method could analyze edible oils to identify characteristic flavor components. As a result, 25 VOC tags were identified and used to characterize soybean oils. Chemometric methods were used to discriminate the authentic sesame oils from those adulterated with soybean oil. The results indicated that this method is an effective approach to measure VOCs in edible oils; such measurements can report counterfeit products.