Comparision of Lipids and Volatile Flavor Components in Chinese Braised Pork in Brown Sauce with Different Sterilization Methods

To investigate the changes of lipids and volatile flavor components of Chinese braised pork in brown sauce after sterilization processes, quantitative analysis of the whole lipid components of unpasteurized, pasteurized, and ultra-high pressure (UHP) braised pork in the brown sauce was conducted using ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry. A total of 251 different lipids were identified. Partial least squares discriminant analysis and hierarchical clustering analysis were used to successfully distinguish the braised pork samples processed with different sterilization methods. Among them, 24 lipid substances were the key compounds to effectively distinguish the lipids, including 15 types of triglycerides (TG), 8 types of phospholipids, and N-acylethanolamine. According to the relative contents of lipid compounds, the braised meat after UHP sterilization was closer to the control group than the ones pasteurized. Using solid-phase micro-extraction coupled with gas chromatography-mass spectrometry, the types and contents of volatile components in braised pork under different sterilization methods were compared. A total of 31 volatile flavor components were identified, including 4 types of alcohols, 4 types of acids, 4 types of lipids, 7 types of alkanes, 2 types of ketones, and 9 types of aldehydes and furan. Based on these results, it was found that the UHP sterilization could maintain the original flavor and lipid composition of Chinese braised pork in brown sauce, which had great potential in meat processing and Chinese cuisine preparation.