超声处理对红豆蛋白-叶黄素复合物结构和功能性质的影响

采用超声处理促进红豆蛋白与叶黄素形成复合物,对其结构和功能性质进行测定与分析,以探究功能性质改善与结构变化之间的关系。采用240 W超声处理10 min可使红豆蛋白与叶黄素的结合率达到最大。热特性和傅里叶变换红外光谱分析表明红豆蛋白与叶黄素形成了复合物,复合物的形成使表面疏水性和游离巯基含量下降,而适当的超声处理使复合物的表面疏水性和游离巯基含量升高,峰值温度和热焓值下降,二级结构中的α-螺旋转变为无规卷曲,导致结构变的松散和无序化,蛋白质功能性质的改善可能与这种结构变化有关。与叶黄素的结合增加了红豆蛋白的溶解度,但不会使其乳化性、乳化稳定性、起泡性和起泡稳定性发生显著改变(P>0.05)。超声处理进一步增加了复合物的溶解度,同时使复合物的乳化性、乳化稳定性和起泡性提高,在240 W超声处理10 min时效果最显著。然而超声处理对于复合物的泡沫稳定性并未产生明显影响。

Effect of Ultrasonic Treatment on Structure and Functional Properties of Red Bean Protein-Lutein Complexes

Ultrasonic treatment was used to promote the formation of complexes between red bean protein and lutein,and their structural and functional properties were measured and analyzed to explore the relationship between improvements in the functional properties and structural changes.The maximum binding rate between red bean protein and lutein was obtained by ultrasonic treatment at 240 W for 10 min.Thermal properties and Fourier transform infrared spectroscopy indicated the formation of red bean protein-lutein complexes,which reduced the surface hydrophobicity and free sulfhydryl content.Appropriate ultrasonic treatment reversed the decrease in both parameters and decreased the peak temperature and thermal enthalpy.Theα-helix structure of the complexes was transformed into random coils under ultrasonic treatment,thus resulting in a looser and disordered structure,which might be related to the improved functional properties of the protein.Combination with lutein increased the solubility of red bean protein,but did not significantly change its emulsifying capacity,emulsion stability,foaming capacity and foam stability(P>0.05).Ultrasonic treatment further increased the solubility of the complexes,and enhanced their emulsifying capacity,emulsion stability and foaming capacity.The most significant improvement was achieved by ultrasonic treatment at 240 W for 10 min.However,ultrasonic treatment had no significant effect on the foam stability of the complexes.