Unraveling the influence of storage condition on off-flavor generation in fried pepper (Zanthoxylum bungeanum Maxim.) oil during storage through molecular sensory science and simulation experiment.

As a popular seasoning, fried pepper oil (FPO) conveniences the cooking of cuisine. However, it is susceptible to rancid off-flavors during storage. Therefore, the aim of this study was to explore the formation pathways of off-flavor compounds using molecular sensory science. 92 volatile compounds were identified under different storage conditions using headspace solidphase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The off-flavor of FPO mainly originated from aldehydes and acids. By orthogonal partial least squares-discriminant analysis (OPLS-DA), 24 compounds were determined as differential marker compounds for distinguishing FPOs for different storage conditions. Based on modeling experiment and isotopic tracing, limonene, linalool and linoleic acid were identified as the main producers of off-flavor compounds. Random forest was the optimal model for screening fresh and storage FPOs. 7 VOCs have been identified as key factors influencing the flavor quality of FPOs. The results provide a theoretical guidance for the regulation of off-flavor in FPO.