微冻及真空包装对原汁整壳贻贝贮存期品质的影响

为研究微冻及真空包装对原汁整壳贻贝贮存期品质的影响,将原汁整壳贻贝进行真空包装及普通包装,于4和-3℃下进行贮存,对样品的感官评分、汁液流失率、pH、电导率、挥发性盐基氮(total volatile basic nitrogen,TVB-N)、2-硫代巴比妥酸(2-thiobarbituric acid,TBA)、菌落总数等指标的变化规律进行分析。结果表明:原汁整壳贻贝在贮藏过程中,随着时间的延长,感官评分下降;pH先降低后升高;汁液流失率、TVB-N、TBA、电导率和菌落总数均随贮存时间的延长而增长。-3℃微冻的保鲜效果明显优于4℃冷藏(P<0.05),真空包装的保鲜效果明显优于普通包装(P<0.05),-3℃微冻结合真空包装保鲜效果最佳,能显著延缓原汁整壳贻贝感官性状的下降(P<0.05),抑制汁液流失率、电导率、TVB-N值、TBA值的上升(P<0.05),延缓pH最低点出现的时间(P<0.05),抑制菌落总数的增长(P<0.05)。综合比较分析,4℃普通包装、4℃真空包装、-3℃普通包装、-3℃真空包装的货架期分别为6、15、15和60 d。因此,微冻结合真空包装能较好维持原汁整壳贻贝的感官性状及品质稳定性,有效延长货架期。

Effects of Partial Freezing and Vacuum Packaging on Storage Quality of Whole Shell Mussel with Original Juice

In order to study the effects of partial freezing and vacuum packaging on the quality of whole shell mussel with original juice during storage,the mussels were packaged in vacuum and ordinary packaging,and then stored at 4 and -3℃ respectively. Quality indexes including the sensory evaluation,drip loss,pH,electric conductivity,total bacterial counts,total volatile basic nitrogen(TVB-N),2-thiobarbituric acid(TBA)were measured. Results showed that the sensory score decreased with the time prolongation during storage. The pH value decreased first and then increased. The drip loss,TVB-N,TBA,electric conductivity and total bacterial counts all increased with the prolongation of storage time. In terms of preservation effect,-3℃ partical freezing was significantly better than 4℃ refrigeration(P<0.05). Vacuum packaging was better than ordinary packaging(P<0.05)significantly. And -3℃ partical freezing combined with vacuum packaging was the best,which could significantly delay the decline of the sensory properties of the whole shell mussel with original juice(P<0.05),and inhibit the increasing of drip loss,electric conductivity,TVB-N value and TBA value(P<0.05). The time at which the lowest pH appeared was delayed(P<0.05),and the increasing in the total bacterial counts was inhibited(P<0.05). Through comparative analysis,the shelf life of 4℃ ordinary packaging,4℃ vacuum packaging,-3℃ ordinary packaging and -3℃ vacuum packaging was 6,15,15 and 60 days,respectively. Thus,the application of partical freezing combined with vacuum packaging could maintain the sensory properties and quality stability of the whole shell mussel with original juice,and effectively extend the shelf life.