Insights into lipid oxidation and free fatty acid profiles to the development of volatile organic compounds in traditional fermented golden pomfret based on multivariate analysis

Abstract

Golden pomfret is rich in polyunsaturated fatty acids (PUFAs), which are susceptible to oxidative hydrolysis during fermentation. Therefore, the objective of this study was to examine the roles of lipid oxidation and lipid oxidation-derived fatty acids (FAs) to the formation of specific volatile organic compounds in fermented golden pomfret. The results showed there was more drastic in lipid oxidation during the pre-fermentation period. There was a persistent increase in superoxide, hydroxyl, singlet oxygen, and alkoxy radical levels. Besides, FA levels increased, and unsaturated fatty acids (UFAs) levels were the highest at all time points. A total of 95 potential volatile compounds were identified and their contents increased during fermentation. Eleven volatile compounds, including hexanal, octanal, 1-octen-3-ol, and 3-methyl-1-butanol, were identified as characteristic volatile compounds in fermented fish. Most of the characteristic volatile compounds comprised lipid oxidation-derived aldehydes and alcohols. Furthermore, the levels of important FAs, such as oleic acid (C18:1, n9c), linoleic acid (C18:2, n6c), and palmitic acid (C16:0), were correlated with the levels of propanal, hexanal, and 1-octen-3-ol. Overall, these results indicated FAs are important precursors of characteristic volatile compounds in fermented golden pomfret and can be manipulated to enhance the flavor of fermented fish.