Effects of fatty acid composition of vegetable oils on youtiao flavor and relevant correlation analysis

To clarify the effects of the fatty acid compositions of vegetable oils on the flavor characteristics of youtiao, twelve vegetable oils with distinct fatty acid profiles were selected for youtiao frying. The contents of flavor compounds in both frying oils and fried youtiao were determined, followed by the calculation of their odor activity values (OAVs) and systematic evaluations of sensory properties and flavor preference.Multivariate statistical analysis was further applied to explore The correlation between the flavor characteristics and the fatty acid composition of frying oils was systematically analyzed. The results showed that flavor-active compounds (FACs) in youtiao fried with fully hydrogenated palm kernel oil were predominantly generated via the Maillard reaction, accounting for 99.6% of the total OAV of FACs. Such samples were characterized by typical caramel and roasted flavor notes and obtained the lowest flavor preference score of 3.02. For youtiao fried with oils containing over 30% linoleic acid, lipid oxidation-derived FACs contributed 35.0%-52.1% of the total OAV. These compounds were mainly derived from linoleic acid oxidation and endowed youtiao with prominent deep-fried, fatty, and mushroom-like flavors, with flavor preference scores ranging from 7.48 to 8.98. In comparison, lipid oxidation-derived FACs in youtiao prepared using oils with more than 75% oleic acid accounted for only 14.0%-19.0% of the total OAV. These FACs were derived from the oxidation of both oleic and linoleic acids and imparted distinct fresh and citrus-like flavor characteristics, corresponding to moderate flavor preference scores of 6.42-6.47. For youtiao fried with linolenic acid-rich oils, lipid oxidation-derived FACs merely contributed 7.9% to the total OAV. The key oxidation product of linolenic acid, (E,E)-2,4-heptadienal, exhibited a limited contribution to the overall flavor profile of youtiao. The flavor of these samples was dominated by Maillard reaction-derived FACs, presenting roasted and caramel notes and a flavor preference score of 6.52. Overall, the fatty acid composition of vegetable oils effectively modulates the relative contributions of FACs derived from lipid oxidation and the Maillard reaction, thereby shaping the unique flavor profiles of fried youtiao and further regulating consumer flavor preference.