脉冲强光对大豆7S球蛋白理化特性、结构变化及潜在致敏性影响的研究

Effects of pulsed light on physicochemical properties, structure changes and potential allergenicity of soybean 7S globulin

中文关键词:  脉冲强光  大豆7S球蛋白  理化特性  结构特性  潜在致敏性

英文关键词:pulsed light  soybean 7S globulin  physicochemical property  structural characteristics  potential allergenicity

中文摘要:

      目的 研究脉冲强光处理对大豆7S球蛋白理化特性、分子结构变化及潜在致敏性的影响。方法 以分离纯化的大豆7S球蛋白为实验材料, 采用Folin酚法、激光粒度仪法、圆二色谱法、荧光分光光度法、紫外分光光度法、酶联免疫吸附法探究脉冲强光处理后的7S球蛋白理化性质、结构特性及潜在致敏性的变化。结果 与对照相比(0 s), 脉冲强光处理能够提高大豆7S球蛋白的溶解性、乳化活性和乳化稳定性, 降低7S球蛋白的平均粒径; 脉冲能量500和700 J时, 随着脉冲时间的增加, α-螺旋含量呈先减少后增加趋势, β-折叠含量呈先增加后减少的趋势, 而能量900 J时, α-螺旋含量显著减少(P<0.05), β-折叠含量变化不显著; 内源荧光强度显著下降(P<0.05), 表明表面疏水性显著增加(P<0.05), 紫外吸光强度增加, 表明脉冲强光处理使7S球蛋白的结构发生改变。随着脉冲能量和脉冲时间的增加, 7S球蛋白抗原抑制率呈先下降后上升的趋势, 且脉冲能量700 J时, 其抑制率最低, 为46.13%, 这可能是7S球蛋白结构的改变导致其抗原表位发生变化。结论 脉冲强光处理能够改善大豆球蛋白的理化特性, 且通过构象的变化影响其潜在致敏性, 为脉冲强光在低致敏大豆蛋白食品中的应用提供一定的理论参考。

英文摘要:

      Objective To investigate the effects of pulsed light treatments on the physicochemical properties, molecular structural changes and potential allergenicity of soybean 7S globulin. Methods The isolated and purified soybean 7S globulin was used as the experimental material, and the changes of physicochemical properties, structural characteristics and potential allergenicity of 7S globulin after pulsed light treatments were investigated by Folin phenol method, laser particle size measurement method, circular dichroism method, fluorescence spectrophotometry, ultraviolet spectrophotometry and enzyme linked immunosorbent assay. Results Compared with the control (0 s), pulsed light treatments could improve the solubility, emulsifying activity and stability of soybean 7S globulin, and decrease the average particle of soybean 7S globulin. When the energy was 500 and 700 J, as the pulsed time increased, α-helix content decreased firstly and then increased, the β-folded content firstly increased then decreased, when the energy was 900 J, the α-helix content significantly decreased, and there was no significant change in β-folded content, the fluorescence intensity significantly decreased (P<0.05), indicating that the surface hydrophobic significantly increased (P<0.05), ultraviolet absorption intensity increased, indicating that pulsed light treatments caused structural changes in 7S globulin. With the increase of pulsed energy and pulsed time, the inhibition rate of 7S globulin antigen showed a trend of decreasing and then increasing, and the lowest inhibition rate was 46.13% at the pulsed energy of 700 J, the change of 7S globulin structure might lead to the change of its epitope. Conclusion The pulsed light treatments can improve the physicochemical properties of soybean 7S globulin, and affect its potential allergenicity through the changes of soybean 7S globulin conformation, which provides a theoretical reference for the application of pulsed light in low allergenic soybean protein food.