鲜活和死后小龙虾的冷藏特性比较

分别以鲜活和死后的小龙虾为实验对象，通过测定其在4?℃冷藏和0?℃冰藏期间菌落总数、pH值、总挥发性盐基氮（total volatile base nitrogen，TVB-N）含量、硫代巴比妥酸（thiobarbituric acid，TBA）值、总巯基含量等生化指标，结合感官评价和色差分析，研究小龙虾的贮藏特性。结果表明，在4?℃冷藏和0?℃冰藏条件下，随贮藏时间延长，鲜活虾和死后虾的菌落总数、TVB-N含量、TBA值、黄度（b*值）以及总色差（ΔE*）均随贮藏时间的延长而呈上升趋势，pH值总体上呈先降低后升高的趋势，感官评分、总巯基含量和亮度（L*值）持续下降。综合各项指标得出，4?℃冷藏条件下的鲜活虾和死后虾的货架期分别为8?d和4?d，0?℃冰藏条件下的鲜活虾和死后虾的货架期分别为12?d和11?d。4?℃冷藏条件下，鲜活小龙虾的品质保持效果显著好于死后虾，0?℃冰藏条件下两种虾的贮藏品质无显著差异。

Comparison of Quality Characteristics of Live and Dead Crayfish during Cold Storage

The total viable count (TVC), pH, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid (TBA) value, sensory evaluation and color of live and dead crayfish were measured during storage at 4 and 0 ℃. The results indicated that the TVC, TVB-N content, TBA value, yellowness (b* value) and total color difference (ΔE*) of both live and dead crayfish increased with storage time irrespective of storage temperature, while the pH increased after an initial decrease and the sensory evaluation score, total sulfhydryl group content and brightness (L* value) continued to decrease. Considering all above indicators together, the shelf lives of live and dead crayfish stored at 4 ℃ were 8 and 4 days, respectively, and the shelf lives of live and dead crayfish stored at 0 ℃ were 12 and 11 days, respectively. When stored at 4 ℃, the quality of live crayfish was significantly better than that of dead crayfish, whereas there was no significant difference in the quality of live and dead crayfish during storage at 0 ℃.