摘要
为分析酶催化途径对秘鲁鱿鱼内源性甲醛产生的影响,研究了秘鲁鱿鱼不同组织中氧化三甲胺脱甲基酶(TMAOase)的活性及酶学性质,并通过体外重组实验分析冻藏过程中TMAOase活性与甲醛生成的相关性。结果显示,鱿鱼不同组织TMAOase活性均较低,而肝脏酶活相对较高。肝脏和肌肉TMAOase酶学性质相似,较佳反应温度40～50℃,表现为热不稳定性。TMAOase催化活性需要一个辅助因子系统,包括Fe2+、抗坏血酸(Asc)和半胱氨酸(Cys)。鱿鱼肝脏-肌肉重组体和TMAOase-肌肉重组体在冻藏过程中甲醛和二甲胺(DMA)含量显著提高,而肌肉中DMA和甲醛含量无显著增加。电镜扫描结果显示,酶促生成的甲醛促进了重组体肌肉组织的交联,使肌肉网络组织结构更加致密。鱿鱼甲醛生成相关酶TMAOase主要集中在内脏组织中,肌肉中酶活性较低,因此酶学途径并非鱿鱼及制品中高含量甲醛的主要来源。
To study the effect of enzymatic catalyzing pathway on the formation of formaldehyde in squid（Dosidicus gigas）from peru,the activity and properties of trimethylamine-N-oxide demethylase（TMAOase） from various tissues was analyzed.The relation between the activity of enzyme and formation of formaldehyde during the frozen stroage was studied in the squid by the in vitro recombing test.The results were showed that the enzyme activity in tissues form squid was low,with the highest activity in liver.The properties of enzyme were similar both in the liver and muscle,with 40～50 ℃ of its optimum temperature,and unstability to heat.Enzyme required a cofactor system containing Fe2＋,ascorbate,and cysteine for full activation.In the recombine mixture of liver or enzyme and muscle of squid,the content of FA and DMA increased significantly during the frozen storage,and the more formaldehyde caused the protein aggregation and denser spectical structure of protein.However,the the content of FA and DMA had no change in muscle of squid.Thus,the enzymatic pathway of TMAOase was unimportant for the formation of formaldehyde.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2010年第2期97-103,共7页
Journal of Chinese Institute Of Food Science and Technology
基金
国家863计划海洋技术领域重点项目(2007AA091806)
浙江省自然科学基金项目(Y3090246)
