Antioxidant activities of young apple polyphenols and its preservative effects on lipids and proteins in grass carp (Ctenopharyngodon idellus) fillets

The aim of this study was to study the antioxidant and antibacterial activities of young apple polyphenols (YAP) and to investigate the application of YAP in grass carp fillets (GCF) stored at 4 degrees C for retarding lipid and protein degradation. The results indicated that YAP had high antioxidant activities in vitro, and the addition of YAP to GCF during low-temperature storage could significantly inhibit the microbial growth; retard the decrease in contents of fatty acids for both unsaturated and saturated ones; and minimize the degradation of salt-soluble myofibrillar protein and sulfhydryl group. The profiles of GCF in the presence and absence of YAP under a scanning electron microscope indicated that YAP could protect GCF from destruction that was resulted from fish deterioration. Therefore, YAP may be developed as natural antioxidants to control lipid and protein degradation and to extend shelf life of freshwater fish fillets.