Untargeted metabolomics coupled with flavoromics reveal the effect of Perilla frutescens water extract marination on the physicochemical attributes and flavors of grass carp cubes

The effects of dried and fresh perilla leave water extract (PLWE) marination on physicochemical properties and flavor of grass carp cubes (GCC) were evaluated. The results demonstrated that GCC marinated with fresh PLWE exhibited low centrifugation loss, cooking loss, fishy odor, and high chewiness, pH ( p < 0.05). GC–MS and GC-IMS results revealed the difference in volatile organic components (VOCs) among the GCC samples, and 14 components were identified as key differential VOCs. Based on untargeted metabolomics analysis, lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds, nucleosides, nucleotides, analogues, phenylpropanoids, polyketides, and benzenoids were identified as differential metabolites among the 751 metabolites. Furthermore, 5 KEGG pathways were identified as key differential metabolic pathways. PLWE might mainly improve the flavor of GCC by inhibiting the production of fishy substances by suppressing the lipid, amino acid, and creatine/choline metabolism. It would provide theoretical guidance for the application of PLWE in enhancing flavor characteristics of freshwater fish ready-to-eat products.