冰衣对冷冻南美白对虾贮藏品质的影响

Effect of Ice Coating on the Quality of Frozen Shrimp(Litopenaeus vannamei)

通过测定-20℃冷冻条件下无冰衣组、15%镀冰衣组和25%镀冰衣组南美白对虾的感官评分、解冻损失、蒸煮损失、挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、盐溶蛋白含量及肌苷酸(inosine-5’-monophosphate,IMP)关联物各比值,研究镀冰衣处理对冻藏南美白对虾品质的影响。通过分析IMP关联物各比值(K、K_i、G、P、H及F_r)与主要鲜度指标间的相关性,探讨更适宜作为-20℃冷冻条件下镀冰衣南美白对虾品质评价的指标。结果表明:随着贮藏时间的延长,3组南美白对虾的解冻损失、蒸煮损失和TVB-N含量均呈明显上升趋势,盐溶蛋白含量显著下降,25%镀冰衣组南美白对虾的品质始终优于无冰衣组和15%镀冰衣组;根据各指标间的Pearson相关性分析,K、K_i、G、P、H及F_r值中,K值更适合用于评价该贮藏条件下南美白对虾的整体质量;无冰衣组、15%镀冰衣组和25%镀冰衣组分别在贮藏第12、16、16周感官不可接受,镀冰衣能够有效延长冻藏南美白对虾的贮藏期。

The effect of ice coating on the quality of frozen shrimp（Litopenaeus vannamei） was assessed by sensory analysis, thawing loss, cooking loss, total volatile basic nitrogen（TVB-N） content, salt-soluble protein and inosinemonpho sphate（IMP）-related compounds. By analyzing their correlations with the main quality indicators, K, K_i, G, P, H and F_r values were screened for their suitability to evaluate the quality of Litopenaeus vannamei during storage. Shrimp samples were left untreated or treated with 15% or 25% ice coating. The results showed that thawing loss, cooking loss and TVB-N content increased significantly with storage time, while salt-soluble protein content showed a substantial decrease. The quality of the 25% ice coating group was always better than that of the control and 15% ice coating groups. Pearson correlation analysis demonstrated that compared to K_i, G, P, H, F_r values, K value was more suitable to evaluate the overall quality of frozen Litopenaeus vannamei. According to sensory analysis, the untreated, 15% ice coating and 25% ice coating groups were evaluated as unacceptable after 12, 16 and 16 weeks of storage, respectively. In conclusion, ice coating could significantly prolong the storage life of Litopenaeus vannamei.