热处理改性对葵花11S球蛋白结构和理化性质的影响-《中国调味品》

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Title:: Effects of Heat Treatment on Structural and Physicochemical Properties of Sunflower 11S Globulin

摘要:: 研究了热处理对葵花11S球蛋白结构和理化性质的影响。将70 g /L 的葵花11S 球蛋白分散液( pH 7.0) 分别于88，98 和108℃条件下热处理30 min，以天然蛋白质为对照，分析热处理蛋白质的二级结构、分子柔性以及氨基酸组成、粒径分布、巯基和二硫键含量的变化。结果表明: 葵花11S球蛋白经88和98℃热处理α-螺旋、β-折叠结构转化为无规则卷曲结构，但108 ℃热处理α-螺旋结构增加。88 ℃热处理蛋白质分子柔性增强，之后随着温度升高，分子柔性减弱。热处理导致葵花蛋白的巯基含量和二硫键含量发生了显著变化，但氨基酸组成随温度变化不显著。热处理导致蛋白质聚集和解离，平均粒径的大小及分布范围改变。

Abstract:: The effects of heat treatment on structural and physicochemical properties of sunflower 11S globulin were studied. Sunflower 11S globulin suspensions ( 7% w/v，pH 7. 0) were heated at 88，98 and 108 ℃ for 30 minrespectively. The secondary structure, molecular flexibility, amino acid composition, particle size distribution, sulfhydryl group and disulfide bond content of the heat-treated proteins were analyzed. The results showed that random-coil structure of sunflower 11S globulin increased corresponding the decreased of α-helix and β-sheet by heating treatment at 88 and 98 ℃, but α-helix content of the protein increased by heating treatment at 108 ℃. The protein molecule flexibility increased after heating treatment at 88 ℃. The molecular flexibility weakened as the temperature increased. The content of sulfhydryl group and disulfide bond modified significantly, while the amino acid composition did not change significantly with the increased of heat treatment temperature. Heat treatment resulted in protein aggregation and dissociation, and the size and distribution of mean particle size were modified.