高强度超声处理对不同盐浓度下鲢鱼肌球蛋白理化特性的影响

Effect of High Intensity Ultrasound on Physicochemical Properties of Silver Carp Myosin with Different Salt Concentrations

以鲢鱼肌球蛋白为对象,研究高强度超声处理对不同盐(NaCl,下同)浓度(0.1、0.2、0.3、0.5、1.0、2.0 mol/L)下肌球蛋白溶解度及粒径的影响,在此基础之上,以低(0.1 mol/L)、中(0.5 mol/L)、高(1.0 mol/L)盐浓度处理为代表,通过静态流变学性能、巯基含量、表面疏水性分析及微观形貌观察等探讨高强度超声对不同盐浓度下肌球蛋白理化特性的影响。结果表明,高强度超声下肌球蛋白理化特性的变化受盐浓度的影响,低盐环境(0.1 mol/L)中,高强度超声处理明显打散了肌球蛋白的粗丝结构,使聚集体的平均粒径和零剪切黏度明显降低,流动性增大。该条件下可使低盐浓度下肌球蛋白的溶解度提高到未超声处理组的10倍左右,与未超声的0.2 mol/L盐浓度下肌球蛋白溶解度相接近。中、高盐浓度下,对照组肌球蛋白的溶解度比低盐浓度下高,高强度超声可诱导肌球蛋白构象发生改变,暴露出活性基团,使溶解度进一步提升,但提升程度低于0.1 mol/L盐浓度条件下的。综上,相较于中、高盐浓度,高强度超声处理对低盐浓度下肌球蛋白理化性质的提升效果更显著,这可为制作低盐鱼糜制品提供理论依据。

In the present study,the effect of high intensity ultrasound(HIU)on the physicochemical properties of silver carp myosin with different salt concentrations(0.1,0.2,0.3,0.5,1.0,2.0 mol/L NaCl)was investigated in terms of solubility,particle size distribution,static rheological properties,and microscopic morphology.The changes in physicochemical properties of myosin induced by HIU were affected by salt concentrations.At low salt concentration(0.1 mol/L),HIU obviously disrupted the structure of myosin filaments,resulting in decreased particle size and zero shear viscosity,and increased fluidity.Moreover,the solubility of HIU treated myosin with low salt concentration was increased about ten times compared to the untreated control with the same salt concentration,while it was close to that of the untreated control with 0.2 mol/L NaCl.For myosin with medium and high NaCl concentrations(0.5 and 1.0 mol/L),the solubility was better than that with low salt concentration.HIU could induce conformational changes in myosin,resulting in exposure of reactive groups and a further increase in the solubility.However,HIU was less effective in increasing the solubility of myosin at medium and high than at low salt concentrations.In summary,HIU can improve the physicochemical properties of myosin more at low than at medium and high salt concentrations,which might provide a theoretical basis for the production of low-salt surimi products.