Abstract:Sensory attributes,total number of bacteria,physical and chemical parameters(proximate composition,texture analysis,color measurements,pH,TBA,TMAN,TVB-N,K-value,Ca2+-ATPase activity,SDS-PAGE)changes of yellow grouper(Epinephelus awoara)stored under vacuum packaging at 0 ℃were investigated.The results showed that yellow grouper was a fish with low level of fat but high level of protein.During the storage,sensory attributes(odor and taste)exhibited significant variations and correlations in storage time(r=0.94 and 0.98,respectively).Taste score increased faster than the odor score,however,neither of them reached the reject limit of 3 scores.There were significant linear increases in total viable counts(TVC)in the storage(r=0.97).TVC on the 12th-day was lower than 4 Log CFU/g,indicating the fillets kept at first grade of freshness,and was 4.34 Log CFU/g at the end of 15 days storage,kept at second grade of freshness.With regards to the texture profile,hardness(r=-0.89),gumminess(r=-0.73),chewiness(r=-0.87)showed a significant and negative correlation with storage time.L* and the chroma values decreased,and b* values increased,reflecting the colour changes experienced by the fillets over time.No significant differences were found in pH and TBA concentrations during the storage and they displayed a weak correlation with time,so they may not be the suitable indicators for reflecting the quality changes of yellow grouper fillets during the storage.The amount of TVB-N and TMA-N significantly increased with time,at the final of storage,TVB-N and TMA-N reached 12.94 mg N/100 g and 0.75 mg N/100 g respectively,and both of them were lower than limit.The proteolytic degradation of muscle protein was observed by SDSPAGE,the results showed that MHC and Actin were hydrolyzed continuously throughout storage.Ca2+-ATPase activity declined fast from the initial value of 0.25 μg Pi/(min·mg)to the final value of 0.07 μg Pi/(min·mg).K value increased fast with time(r=0.98)and reached 54.91% at the end of storage,keeping the middle level of freshness.The results suggested that total viable counts(TVC)increased slowly under vacuum packaging at 0 ℃,and it kept good sensory characters,inhibited the changes of the paraments(TVB-N value,etc.)and hydrolysis of protein.The sensory attributes,microbiological counts,texture(hardness,cohesiveness and chewiness),colour(L*、b*,and Cab),TVB-N,TMA-N,Ca2+-APTase activity and K value exhibited strong correlations with storage time and were sensitive.Therefore,they may be considered as good indicators for evaluating yellow grouper spoilage during the storage under vacuum packaging at 0 ℃ for 15 days,but the consideration of shelflife should be combined with all those indicators.