高强度超声处理对大豆7S和11S球蛋白结构和理化性质的影响

以大豆7S和11S球蛋白为对象,研究了高强度超声处理(150、450、1350 W)在不同时间条件(15、30 min)下对7S和11S结构和理化性质的影响.结果表明:超声处理不改变7S和11S的一级结构,但能够使二级结构中各组分含量发生改变.同时,7S和11S的荧光强度在超声处理后降低,表面疏水性(H0)显著增加(P...

Effect of High Intensity Ultrasound on the Conformational and Physicochemical Properties of Soy 7S and 11S Globulin

The effects of high intensity ultrasound treatment(150,450,1350 W) on the conformational and physicochemical properties of soy 7 S and 11 S globulin for different durations(15,30 min) were investigated.The results showed that ultrasound treatment did not change the primary structures of 7 S and 11 S,but were able to change the content of the components in the secondary structure.Ultrasound treatment resulted varying degrees of reduction in fluorescence intensity and a significant increase(P<0.05) in surface hydrophobicity(H0) for 7 S and 11 S.Particle size distribution measurements showed that the droplets of 7 S and 11 S were more uniformly distributed after ultrasound treatment and that the stability of the protein solutions was improved.Differential scanning calorimetry(DSC) results showed that the enthalpy(ΔH) decreased from 1.22 J/g to 0.17 J/g for 7 S and from 1.41 J/g to 0.53 J/g for 11 S after sonication,requiring less energy to unfold the protein structure.In terms of physicochemical properties,the emulsification activity and emulsion stability of 7 S and 11 S increased significantly(P<0.05) after sonication,and the solubility increased by up to 12.85% and10.57%,respectively.In addition,cryo-scanning electron microscopy(Cryo-SEM) observations revealed that the microstructure of 7 S and 11 S changed after sonication from a more ordered reticular aggregated state to a disordered state.Thus,high intensity ultrasound treatment can obviously affect the structure and physicochemical properties of 7 S and 11 S.