高压处理对大米蛋白溶解性及其分子特征的影响

研究了pH 8.0和pH 10.0条件下500 MPa高压处理对热变性大米蛋白溶解性的影响,并用Sephadex G-100色谱和SDS-PAGE分析了其分子特征的变化,用扫描电镜观察了大米蛋白的表观特征。结果显示,pH 8.0时500 MPa处理可使大米蛋白的溶解性由12.03%提高到19.15%,pH 10.0时高压处理则可由16.60%提高到24.87%。高压处理后的大米蛋白颗粒表面疏松,可使较大的蛋白质分子溶出,也产生了更小的蛋白质分子,且高压与非高压时溶出的蛋白质组分具有不同的紫外吸收特征。高压处理后的可溶性蛋白中均含有14、35 ku和少量22 ku亚基,非可溶性部分中除上述亚基外,还含有12、16、110 ku亚基。表明不同高压处理影响大米蛋白的溶解性能和分子特征,但对亚基的影响不明显。

Effect of High-pressure on the Solubility and Molecular Character of Rice Protein

The effect of High Hydrostatic Pressure(HHP)processing on the solubility and molecular character of thermo-denatured rice protein was studied by Sephadex G-100 chromatography,Sodium Dodecyl Sulfate Polyacylamide Gel Electrophoresis(SDS-PAGE)and Scanning Electron Microscope(SEM).The results showed that after treated by HHP,The ratio of soluble rice protein was increased from 12.03%(at 0.1 MPa,pH 8.0)to 19.15%(after 500 MPa for 30 min,pH 8.0)and from 16.60%(at 0.1 MPa,pH 10.0)to 24.87%(after 500 MPa for 30 min,pH 10.0)receptivity;The surface of rice protein particles became loosen,the bigger molecule of the protein was dissolved in the solution and smaller molecular protein was produced,compared with that of not HHP treated protein.The solubility rice protein produced by different pH and HHP processing contained 14,35 and 22 ku subunits,but the insolubility rice protein,in addition to these subunits,contained 12,16 and 110 ku subunits also.