镀冰衣在保持凡纳滨对虾冻藏过程脂质稳定性的作用

Effect of Ice Glazing on the Lipid Stability of Litopenaeus vannamei During Frozen Storage

中文关键词: 凡纳滨对虾  冻藏  冰衣  脂质  保水性  稳定性

英文关键词: Litopenaeus vannamei  Frozen storage  Ice glazing  Lipid  Water retention  Stability

中文摘要:

      水产品冻藏过程中脂质变化是引起品质劣化的重要原因，为探究凡纳滨对虾(Litopenaeus vannamei)冻藏过程脂质变化以及冰衣对脂质的影响，将其进行镀冰衣处理后在–20℃冻藏180 d，定期取样分析解冻损失率、蒸煮损失率、总脂含量、脂质组成、酸价(acid value, AV)、过氧化值(peroxide value, POV)和硫代巴比妥酸反应物含量(thiobarbituric acid reactive substances, TBARS)等指标的变化。结果显示，随着冻藏时间的延长，对照组和冰衣组样品的解冻损失率、蒸煮损失率呈上升趋势。从冻藏30 d开始，冰衣组的解冻损失率极显著低于对照组(P<0.01)，冰衣组冻藏60 d及更长时间的样品，其蒸煮损失率极显著低于对照组(P<0.01)，表明镀冰衣可以提高冻藏凡纳滨对虾的持水能力。冻藏期间，对照组和冰衣组总脂含量变化不大，但脂质组成均发生显著变化，磷脂和甘油三酯含量下降，游离脂肪酸含量上升，胆固醇含量相对稳定。两组样品脂质氧化指标的变化规律基本一致，AV和TBARS在冻藏期间不断上升，POV在冻藏前60 d先升高后下降，之后缓慢增加，但冰衣组脂质氧化的各项指标均低于对照组，表明镀冰衣有助于保持凡纳滨对虾冻藏过程中脂质的稳定性。

英文摘要:

      Lipid changes during the freezing process is the primary reason for the deteriorating quality of aquatic products. To explore the lipid changes in the shrimp Litopenaeus vannamei during frozen storage and the effect of ice coating on lipids, the glazed shrimp were stored at −20℃ for 180 d and sampled regularly for the analysis of the thawing loss rate, cooking loss rate, total fat content, lipid composition, acid value (AV), peroxide value (POV), and thiobarbituric acid reactive substances (TBARS). The results showed that the thawing and cooking loss rates of shrimp increased during frozen storage, which were significantly lower in the ice-coated group than in the control group (P<0.01), indicating that ice coating can improve the water holding capacity of shrimp meat in frozen storage. The total lipid content of the shrimp did not change substantially, but the lipid composition did. The concentrations of phospholipids and triglycerides decreased, free fatty acids increased, and cholesterol was relatively stable. The changes in the lipid oxidation indices of the two groups were similar. The AV and TBARS levels increased continuously. The POV first increased and then decreased until 60 d, and then slowly increased. However, the lipid oxidation indicators of the ice-coated group were lower than those of the control group, indicating that ice coating is helpful for maintaining the lipid stability of shrimp during frozen storage.