北极虾在不同冷藏条件下的质量变化与质量指标

采用感官评估、物理、化学、微生物分析方法，对贮藏在不同冷藏条件下的北极虾的质量变化与质量指标进行了研究。保藏方法分别为传统冰块冷却法、液态冰冷却法、盐水-冰混合冷却剂法，贮藏环境温度为-1．5℃或1．5℃。研究结果表明，液态冰冷藏法对延缓虾腐败变质的效果比传统冰块冷藏法、盐水-冰混合冷却剂冷藏法好。经过1d的贮藏后发现，无论在-1．5℃还是1．5℃的环境温度下，保藏在液态冰中虾的挥发性总氮(TVB-N)都有所下降，并且在-1．5℃的环境温度下，其TVB-N值在3d后才回升到刚开始贮藏时的水平，而在其它保藏方法中，虾的TVB-N值始终随贮藏时间的延长而增加；除保藏在液态冰-1．5℃环境中虾的三甲胺(TMA)在贮藏的第1天有所降低以外，其它各试验组虾的TMA值均随贮藏时间的延长而增加。检测结果还表明，保藏在传统冰块及盐水-冰混合冷却剂中虾的细菌总数(TVC)增加最快，其次是保藏在液态冰中1．5℃的环境下。而保藏在液态冰中-1．5℃的环境下，虾的细菌繁殖最慢，并且在贮藏初期，产生了明显的细菌总数降低及细菌繁殖被抑制的现象。采用主要因子分析(PCA)和方差分析(ANOVA)发现，质量指标如TVB-N、TMA、TVC、pH、NH3(电子鼻测量值)和感官评估结果等相互之间存在着良好的相关性。

Research on quality changes and indicators of Pandalus borealis stored under different cooling conditions

The quality changes of Northern shrimp, Pandalus borealis, stored in ice, liquid-ice or salt-water mixed with ice, either at ambient temperature of -1.5 or 1.5℃, were evaluated by using sensory assessment, physical methods, chemical and microbial analysis. Storage in liquid ice was more effective than ice or salt-water mixed with ice, in delaying spoilage of the shrimp. It was observed that the total volatile nitrogen (TVB-N) content decreased during the first day in shrimp stored in liquid ice at both -1.5°C and 1.5°C and its formation was further delayed for 3 days in shrimp stored at -1.5°C. In other groups the TVB-N content increased with time. The trimethylamine (TMA) value increased gradually with storage time, in all samples, except for the one stored in liquid ice at -1.5℃ during the first day of storage. Total viable counts (TVC) showed that bacteria grew most quickly in shrimp stored in ice and in salt-water ice, followed by those in liquid ice at 1.5℃ or -1.5℃ respectively throughout the storage period. Lowest counts were observed in sample stored in liquid ice at -1.5℃ where the lag phase of growth of bacteria was apparently extended at the beginning of storage. Principal component analysis (PCA) and analysis of variance (ANOVA) were performed to analyse the variation and correlation of indicators. The results show good correlation between some of the quality indicators, TVB-N, TMA, TVC, pH, NH3 response of electronic nose and sensory evaluation.