实验采用碱提酸沉和稀碱脱脂除杂的方法，分别得到两种米渣蛋白（碱提蛋白、除杂蛋白）。测定两种蛋白的功能性（溶解度、乳化性），实验显示，在pH 2.0~pH 11.0范围内，两种蛋白的溶解性和乳化性均呈现先降低后升高的趋势，碱提蛋白相比除杂蛋白，具有更好的溶解性和乳化性。为了更好地分析两种蛋白性质差异性，实验通过测定蛋白的表面疏水性、粒度、分子量和表面微观形态，表征两种蛋白的聚集态变化。碱提蛋白具有高的表面的疏水性和更小的粒度，通过扫描电镜观察发现，碱提蛋白呈现表面粗糙的颗粒堆积，而除杂蛋白表面较平滑，蛋白颗粒呈现相互团聚交联的状态。实验表明，两种提取方法得到的蛋白形成了不同的聚集态，与除杂蛋白相比，碱提蛋白具有更小的聚集体颗粒，同时暴露出更多的疏水性基团，使其表面疏水性高于除杂蛋白，从而表现出更高的溶解度和乳化性。

Rice residue proteins were obtained by either alkaline extraction-acid precipitation process (alkali-extraction) or dilute alkali degreasing (purification), and the functional properties (solubility and emulsifying properties) of the resulting two types of proteins were studied. The results showed that between pH 2.0 and 11.0, the solubility and emulsifying properties showed an upward trend after an initial decline, where the alkaline-extracted protein exhibited superior solubility and emulsifying properties compared to the purified protein. To further investigate differences in their functional properties, changes in the aggregation state of the two proteins were studied by measuring surface hydrophobicity, particle size distribution, molecular weight, and surface morphology. The alkaline-extracted sample showed higher surface hydrophobicity and smaller particle size. Scanning electron microscopy showed that the surface of alkaline-extracted protein was rough with packed particles and that of purified protein was relatively smooth with cross-linked particles. The results indicated that the proteins extracted by the above two extraction methods formed different aggregation states. Compared with the purified protein, alkaline-extracted protein showed smaller aggregated particles and exposed more hydrophobic groups, thus exhibiting higher surface hydrophobicity. Therefore, the alkaline-extracted protein exhibited better solubility and emulsifying properties.

“十二五”农村领域国家科技计划课题（2012BAD37B02-05）；赣鄱英才555工程(18000007)