Improving Flavor Quality in Bighead Carp (Aristichthys Nobilis) Fillets During Chilled Storage with Chitosan-Egcg Coating: Insights into its Underlying Regulatory Mechanisms

Abstract

This research assessed the influence of chitosan-EGCG coating on the flavor characteristics of bighead carp fillets and examined the underlying regulatory mechanisms through flavor-converting enzyme activities, high-throughput sequencing, and metabolomics analysis. Sensory evaluation, E-nose, and volatile and ATP-related compounds monitoring demonstrated that the chitosan-EGCG coating significantly decreased off-flavor compounds, improving overall flavor quality. The free amino acids (FAA) and free fatty acids (FFA) concentrations, and the activity of flavor-converting enzymes, were significantly reduced by the chitosan-EGCG coating. Additionally, the chitosan-EGCG coating effectively slowed the metabolism of amino acids, nucleotides, and carbohydrates, particularly lipid metabolism. Correlation analysis indicated significant positive associations between key flavor compounds and FAA, FFA, lipoxygenase, alcohol dehydrogenase, and lipid metabolites. Lactococcus, Serratia, and Aeromonas were the primary microorganisms influencing the flavor profile. These findings enhance understanding of flavor deterioration mechanisms and propose methods for preserving the flavor quality of bighead carp fillets during chilled storage.

Keywords: Aquatic products, Epigallocatechin gallate, Flavor metabolism, Electronic nose, Flavor-converting enzyme