紫苏饼粕浓缩蛋白溶解性与乳化特性的研究

Solubility and Emulsifying Properties of Perilla Seed Meal Protein Concentrate

以氮溶解指数、乳化活性和乳化稳定性为考察指标,研究了温度、pH值、离子强度、蛋白质质量浓度、蔗糖添加量等对紫苏饼粕浓缩蛋白溶解特性和乳化特性的影响。紫苏饼粕浓缩蛋白的NSI在50～60℃范围内最大。紫苏饼粕浓缩蛋白的等电点在pH4.4,其溶解度与pH值的关系呈典型的V型。低浓度(<0.05 mol/L)的NaCl对蛋白质的溶解性和乳化性均表现为正面作用,而高浓度(0.1～0.25 mol/L)NaCl对其影响则截然相反。添加蔗糖(0%～2.5%)明显改善了紫苏饼粕浓缩蛋白的乳化活性与乳化稳定性。

The effects of temperature, pH, ionic strength, protein concentration and sugar on the solubility and e- mulsifying properties of perilla seed meal protein concentrate were investigated with indexes of nitrogen solubility, e- mulsifying activity and emulsifying stability. Results： The denantural temperature of perilla seed meal protein concentrate is 50 - 60 ℃ ; its isoelectric point is pH 4.4, and the relationship between its solubility and pH forms a typical V curve. Low concentration of NaCl （ 〈 0.05 mol/L） enhances the solubility and emulsifying properties of perilla seed meal protein concentrate; however, NaCl with high concentration （0.1 -0.25 mol/L） deteriorates these properties,and addition of sugar （0% -2.5% ） facilitates significantly the emulsifying activity and stability.