Abstract: To better understand the effect of liquid nitrogen (LN) freezing on changes in nutrients of soft-shell green mud crab (Scylla paramamosain) with during its frozen storage, a nuclear magnetic resonance (NMR)-based metabolomics technique was used to monitor metabolic profiles of edible tissues of soft-shell crabs with LN freezing during short-term (7 days) and long-term (8 months) frozen storage(-20℃). The results showed that short-term frozen storage and LN freezing showed no significant effect on crab metabolic profiles. However, the muscle dimethylamine level was tripled whereas the hepatopancreas inosine level was doubled after short-term frozen storage. In contrast, LN freezing could inhibit the increase of these two metabolites. Besides, long-term frozen storage with LN freezing lead to a significant increase in the muscle inosine, maltose, and glucose as well as hepatopancreas inosine, glutamine, and uridine of soft-shell crabs. These findings demonstrated the effectiveness of LN freezing to ameliorate the quality deterioration of soft-shell crab during its frozen storage. This study provide a theoretical reference for understanding the quality change of soft shell crobs during frozen storage.

Key words: mud crab (Scylla paramamosain), soft-shell crab, liquid nitrogen freezing, nuclear magnetic resonance, multivariate data analysis

摘要： 为探讨液氮(LN)冻结拟穴青蟹软壳蟹在冻藏期间的营养物质变化,本研究采用基于核磁共振(NMR)的代谢组学技术分析了LN冻结软壳蟹可食组织代谢谱在短期(7 d)和长期(8个月)冻藏期间的变化。结果表明,-20℃冻藏和LN冻结均对短期冻藏的软壳蟹代谢谱无显著影响(P>0.05),但 -20℃ 冻藏导致软壳蟹肌肉的二甲胺和肝胰腺的肌苷水平倍增,而LN冻结能抑制这两种物质的增加。长期冻藏可导致LN冻结软壳蟹肌肉的肌苷、麦芽糖和葡萄糖以及肝胰腺的肌苷、谷氨酰胺和尿苷水平显著升高(P<0.05)。表明LN冻结可有效缓解长期冻藏软壳蟹的质量下降。本研究结果为揭示软壳蟹冻藏过程中的品质变化提供了理论参考。

关键词: 拟穴青蟹, 软壳蟹, 液氮冻结, 核磁共振, 多变量数据分析