南美白对虾冰温气调保鲜效果评价

摘要

将鲜南美白对虾进行空气包装(AP)、真空包装(VP)、气调包装(MAP，75% CO2/25% N2)，分别冰温(－2.3～0℃)贮藏和冰藏，通过研究样品贮藏过程中多酚氧化酶(PPO)活力、总挥发性盐基氮(TVB-N)、菌落总数(TPC)、汁液流失率(DL)的变化，结合感官指标评价冰温气调保鲜的效果。结果表明：南美白对虾的PPO活力变化与腐败变质同步；冰温结合MAP能有效防止褐变，货架期可达10d，比冰藏结合AP延长了约3倍，此时样品色泽良好，TPC、TVB-N、DL分别为5.4(lg(CFU/g))、25.6mg/100g、3.13%，而其他包装样品已腐败。VP也能较好的保持色泽，但贮藏后期汁液流失相对严重，影响外观。%The effects of air packaging (AP), vacuum packaging (VP) and modified atmosphere packaging (MAP) on preservation of white shrimp (litopenaeus vannamei) during controlled freezing-point (CF,-2.3-0℃) storage and ice storage were investigated. The influence of different packaging method was assessed on the basis of changes of polyphenol oxidase (PPO) activity, total volatile base nitrogen (TVB-N), total plate count (TPC) and drip loss (DP) combined with sensory evaluation. The results indicated that the PPO activity of white shrimp changed synchronously with its deterioration during storage. Combined use of MAP and CF storage effectively prevented the occurrence of browning in Pacific white shrimps and had an extended shelf life of 10 days compared to AP treated shrimps stored in ice. The white shrimps presented a better color and TPC, TVB-N, TBC and DP were about 5.4 lg((CFU/g)), 25.6 mg/100 g and 3.13%, respectively. However, shrimps treated by AP or CP showed deterioration. Sensory analyses indicated that shrimps treated by VP also had better color compared to AP while but the drip loss was relatively higher, which in turn influenced the sample’s appearance during the late period of storage.