Flavor is a decisive sensory property to determine the popularity of deep-fried foods, the oil types and frying cycles are paramount factors to influence the manufacture of volatiles by oxidative degradation of fatty acids. In this study, the volatile compounds of French fries were monitored in 11 frying oils, and 48 frying cycles in soybean oil (SO), palm oil (PO), high-oleic rapeseed oil (HORSO). The partial least squares regression analysis investigated that (E,E)-2,4-decadienal, 2,4-decadienal, (E,E)-2,4-nonadienal, pentanal, 2-pentylfuran, 1-pentanol, trans-4,5-diepoxy(E)-2-nonenal were associated with the initial content of linoleic acid and nonanal, decanal were related to the oleic acid. The aroma profile analysis showed rice bran oil, sunflower oil and soybean oil with higher linoleic acid exhibited good deep-fried flavor. The key odor compounds (E,E)-2,4-decadienal and 2,4-decadienal of French fries in SO, PO and HORSO increased to maximum values then decreased slowly with the frying cycles. The principal component analysis results showed that the French fries in the first frying cycle had obvious distinguish with other cycles, and French fries in SO could be discriminated from those in PO and HORSO for its higher volatile compounds. This study will provide a guideline for consumers to choose the appropriated frying oil and achieve the scientific frying for ideal flavor of French fries.
