Vacuum impregnation of fish gelatin combined with grape seed extract inhibits protein oxidation and degradation of chilled tilapia fillets.

• Vacuum impregnation was effective in introducing coatings to fillets. • The gelatin-GSE coating inhibited protein oxidation during chilled storage. • The gelatin-GSE coating maintained the morphology of myofibrils. • The gelatin-GSE group showed better quality and freshness than the control group. The present study studied the effects of fish gelatin (FG) incorporated with grape seed extract (GSE) through vacuum impregnation (VI) on refrigerated tilapia (Oreochromis niloticus) fillets over 12 days. The VI of FG-GSE significantly improved the quality of the fish by decreasing drip loss, texture changes, and microbial survival. It also delayed protein oxidation by inhibiting the formation of disulphide bonds and carbonyl groups, and maintaining a higher sulfhydryl content and Ca2+-ATPase activity. Regarding myofibril degradation, FG-GSE maintained their secondary structure by increasing the ratio of α-helices and β-sheets (70.88–75.51%). Atomic force microscopy further revealed that the FG-GSE coating preserved the myofibril nanostructure by maintaining their length, width, and height. Overall, the synergistic effects of VI with 3% FG and 0.9% GSE suggested a promising approach for fillet preservation. [ABSTRACT FROM AUTHOR]