Potential of epigallocatechin gallate to enhance the quality of lightly brined black carp (Mylopharyngodon piceus) fillets: Modifications of oxidative stability, tissue structure, and intermolecular interactions

This study investigated the effects of epigallocatechin gallate (EGCG) incorporation on the quality attributes and underlying mechanisms in lightly brined black carp fillets during frozen storage. Incorporation of EGCG during brining significantly reduced both peroxide value and thiobarbituric acid reactive substances value ( p <0.05). Notably, the 0.6% EGCG group exhibited the lowest peroxide value. Thiobarbituric acid reactive substances remained stable in all EGCG groups within 15 days ( p >0.05), while it increased continuously in the 0.1% EGCG group thereafter ( p <0.05). When the EGCG concentration did not exceed 0.2%, the fillets maintained high water-holding capacity, desirable texture, and structural integrity within 30 days of frozen storage. Further increasing the EGCG concentration beyond 0.2% provided no additional benefits for preserving protein properties and tissue structure. Therefore, incorporation of 0.2% EGCG is recommended as optimal to improve the overall quality and storage stability of lightly brined fillets. These findings provide valuable theoretical insights for quality enhancement of freshwater fish products.