冻结速率对凡纳滨对虾虾仁贮藏特性的影响

Effect of Frozen Temperature on Quality of Penaeus Vannamei during Frozen Storage

摘要:

本文以凡纳滨对虾（Penaeus vannamei）虾仁为原料，分别采用-80 ℃和-20 ℃两种冻结条件对虾仁进行冻结处理，分析冷冻速率对凡纳滨对虾虾仁贮藏过程中理化、鲜度及色泽特性的影响，明确冻结速率对虾仁解冻后的质量变化特征的影响规律。总体来讲，冻藏过程中虾仁质量变化趋势基本一致，随着冻藏时间的延长，虾肉解冻损失率增加，鲜度降低，pH呈下降后上升的趋势，TVB-N值上升，产品的亮度指标L*升高。冻结速率对虾仁的贮藏特性影响差异显著，冻藏6 d后冻结速率对虾仁解冻损失率、鲜度指标影响出现分化，-80 ℃速冻处理可明显改善虾仁的解冻失水，保证虾仁鲜度。20 d后，pH值、TVB-N值变L*值变化情况也表明-80 ℃速冻在一定程度上可以减轻虾仁贮藏过程中的质量劣化程度。

Abstract:

The effect of frozen treatment temperature(-80 ℃ and -20 ℃) on quality of Penaeus vannamei was investigated by analyzing of biochemistry, freshness and color characters of prawn samples. The frozen treatment induced the increase of thawing loss, TVB-N and L*, decrease of freshness. The pH of prawn decreased in the first few days and then increased rapidly. The frozen temperature showed different influence on prawn storage character, especially on thawing loss and freshness index after being storage for 6 days. Frozen treatment at -80 ℃ may effectively reduce the thawing loss and thus keep freshness of the prawn. After a -80 ℃ frozen treatment for 20 days, analysis of pH, TVB-N and L* shown that -80 ℃ frozen treatment could alleviate quality changes of prawns.