不同离子强度下罗非鱼肌球蛋白热变性聚集研究

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  • (广东海洋大学食品科技学院,广东省水产品加工与安全重点实验室,水产品深加工广东普通高等学校重点实验室,广东湛江,524088)
李婷(1994-),女,在读硕士,研究方向:罗非鱼肌球蛋白增溶和稳态化研究。E-mail:LTZzang@163.com.

网络出版日期: 2018-02-02

基金资助

国家自然科学基金项目(31201389);广东省教育厅科技创新项目(2013KJCX0098)

Study on the thermal denaturation and aggregation of tilapia myosin under different ionic strength conditions

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  • (College of Food Science and Technology, Guangdong Ocean University, 524088,China)

Online published: 2018-02-02

摘要

以罗非鱼肉为原料,提取肌球蛋白,分析不同离子强度(1、50、150、300、600mmol/KCl)下热处理(40~80℃,1℃/min)对其浊度、溶解度、表面疏水性、α-螺旋含量及聚集体粒径的影响。结果显示,离子强度及热处理温度明显影响肌球蛋白的热变性聚集。在低离子强度(1~150 mmol/L KCl)下,肌球蛋白聚集成纤丝,溶解性差,热处理后分子聚集沉淀,溶解度和α-螺旋含量减小(p<0.05),体系热稳定性差;在高离子强度(300~600 mmol/L KCl)下,肌球蛋白分子解离成单体,溶液澄清,当热处理温度高于50℃时,肌球蛋白溶解度下降,表面疏水性增加,α-螺旋含量显著减小(p<0.05),但分子聚集不明显。总体分析,高盐离子的静电屏蔽作用导致肌球蛋白纤丝解离,由此也会对肌球蛋白分子结构有一定的保护作用,热稳定性相对较好。

本文引用格式

李婷, 朱潘红, 齐慧红, 等 . 不同离子强度下罗非鱼肌球蛋白热变性聚集研究[J]. 食品与发酵工业, 2018 , 44(1) : 86 . DOI: 10.13995/j.cnki.11-1802/ts.014770

Abstract

Tilapia was used as material to extract myosin. The effects of heat treatment (40-80 ℃, 1℃/min) on the turbidity, solubility, surface hydrophobicity, α-helix contentand aggregated particles of myosin were investigated underdifferent ionic strength (1,50,150,300,600 mmol/KCl).The results showed that the ionic strength and heat treatment significantly affected the thermal denaturation and aggregation of myosin. Myosin has poor solubility because of it assembles and forms a filamentous polymer under low ionic strength (1-150 mmol/L KCl), after heat treatment, the molecular aggregation precipitates, the solubility and α-helix content decreased (p<0.05), the thermal stability of the myosin in this system was undesirable. Whileunder the high ionic strength (300-600mmol/L KCl), myosin dissociated into monomer,the solution is clear.When the temperature is higher than 50 ℃, a increase in turbidity and decrease in solubility of tilapia myosin was detected, accompanied by increasing in surface hydrophobicity and a significant loss of α-helix (p<0.05), but the molecular aggregation is not obvious.The results indicated that the electrostatic shielding of high salt ions inhibited formation of myosin filament, which also protects the molecular structure of myosin.So that the myosin that under the high ionic strength has better stability.
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