Abstract:To investigate the influence of vegetable oil on the physicochemical properties and flavor of chili oil, the capsaicinoid content, color difference, peroxide concentrations and volatile organic compounds (VOCs) of chili oil samples prepared from six kinds of edible vegetable oils (rapeseed oil, corn oil, soybean oil, olive oil, tomato seed oil, and camellia oil) were determined using high performance liquid chromatography (HPLC) and gas chromatography-ion mobility spectroscopy (GC-IMS). The six chili oil samples differed significantly in their capsaicinoid and peroxide concentrations and pungency (P<0.05) but had similar color difference values. GC-IMS analysis detected the presence of 88 VOCs, with aldehydes being the most predominant, comprising 22 different types. Orthogonal partial least squares-discriminant analysis screened out 19 key differential markers (VIP>1.2) for key flavors, among which 4-methylthiazole (VIP = 3.16) contributed the most to the flavor of the chili oil samples. The differences in VOCs among the six chili oil samples were effectively distinguished using GC-IMS fingerprint spectra combined with principal component analysis and heat map cluster analysis. The different vegetable oils had varying effects on the flavor and quality of chili oil, with rapeseed oil having a particularly prominent effect. Rapeseed-based chili oil was moderately pungent (17.72±0.12°), had a pure color and the richest aroma, and showed high stability. The findings of this study can serve as a theoretical basis for the production and identification of chili oil products with distinct flavors.
