罗非鱼片真空微冻保鲜研究

为探索罗非鱼片的保鲜方法，采用真空包装和微冻处理罗非鱼片，对其在贮藏过程中的感官特性、水分散失率、僵硬期、肌肉硬度、挥发性盐基氮(TVB-N)和水分活度等进行比较分析，评价罗非鱼片在真空包装和微冻条件下的保鲜效果。结果表明：罗非鱼在3℃水中经30min即可致死，鱼片比自然死亡的僵硬时间可延长约100min；先真空包装再微冻处理比先微冻再真空包装的水分散失率减少约2.6%。经－7℃和－4℃条件贮藏15d，鱼片的TVB-N≤15mg/100g；－7℃条件贮藏的鱼片TVB-N比－4℃的低约25%。

Fresh-keeping Technology for Tilapia Fillets by Vacuum Packaging Followed by Partial Freezing

Changes in physical and chemical properties such as sensory quality, water-loss rate, stiffness period, hardness degree, total volatitle base-nitrogen (TVB-N) value and water activity during the storage of tilapia fillets subjected to both partial freezing and vacuum packaging at －4 ℃ or －7 ℃ were analyzed to evaluate the fresh-keeping effect of vacuum package and partial freezing storage. Results indicated that tilapia lived in 3 ℃ water for 30 min would die. Its stiffness period was extended to 100 min compared with that of the normally dead tilapia. Initial vacuuming treatment followed by partial freezing treatment could reduce water loss rate by 2.6%, when compared with partial freezing first and then vacuum packaging. After 15 days of storage at －4 ℃ or －7 ℃, (TVB-N) values of tilapia fillets were less than 15 mg/100 g, and the values after the storage period at －7 ℃ were approximately 25% lower than those at －4 ℃.