Dynamic changes in postmortem quality of grass carp ( Ctenopharyngodon idella) ) muscle: From the perspectives of muscle degradation and flavor evolution

This study investigated the dynamic changes in muscle degradation and flavor evolution of grass carp during postmortem refrigerated and ambient storage, exploring their interconnections. The results revealed gradual degradation in muscular chemical compositions, including lipid, protein, and ATP, alongside varying deterioration in associated biochemical indices during postmortem storage, leading to disrupted muscle integrity. SPME-GC-MS analysis unveiled that carbonyls and alcohols predominantly constituted the volatile compounds in postmortem muscle. E-nose analysis displayed intense responses to nitrogen oxides, broad-alcohols, aldehydes, and ketones, but weak responses to aroma components. E-tongue analysis manifested heightened bitterness and astringency, alongside reduced umami. Correlation analyses and mechanistic explorations revealed a strong association between muscle degradation and flavor evolution, jointly contributing to declining flesh quality. Overall, this quality analysis aided in comprehending the postmortem muscle changes and provided supports for improving the preservation techniques and quality control of freshwater fish.