Abstract: Different pretreatment techniques were compared for their effectiveness in preserving the quality of silver carp meat. Two techniques that were found to be the most effective among the ones tested were selected for further investigation. Our focus was on exploring the pattern of quality changes in pretreated fish meat during refrigeration storage and the underlying mechanism. The results showed that both control and modified atmosphere packaged fish were spoiled after refrigeration storage for two weeks. Ultra-high pressure (UHP) processing and ClO2 + 100% CO2 modified atmosphere packaging (MAP) were the most effective pretreatments for preserving fish quality. The water-holding capacity and texture characteristics of UHP-treated sample were significantly improved, and the cooking loss rate was significantly reduced (P < 0.05) relative to the untreated control. The quality of ClO2 + 100% CO2 MAP packaged sample was not maintained so well as UHP-treated sample but was maintained better than the control group. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis and Raman spectroscopy showed that UHP treatment promoted the formation of new hydrogen bonds in fish meat, making the protein structure more orderly compared with the control group and consequently improving the quality characteristics of fish meat. ClO2 + 100% CO2 MAP could improve the quality of fish meat by inhibiting endogenous enzyme activity and as a result reducing the degradation of fish proteins during storage.

Key words: silver carp, chlorine dioxide, ultra-high pressure, preservation, quality change