核桃粕蛋白提取纯化工艺优化及其功能性质分析

为获得优质的核桃粕蛋白，本研究通过单因素实验和响应面法分别对碱溶酸沉法提取核桃粕蛋白工艺和糖化酶纯化核桃粕蛋白工艺条件进行优化，并对其溶解性、吸水性、乳化性等功能性质进行了分析。结果表明，最佳提取工艺条件为：pH12，温度55℃，时间90 min，料液比1:40 g/mL。在此条件下，核桃粕蛋白的提取率可达到81.89%±1.64%，其沉降点是pH4.5。最佳纯化工艺条件为：pH4.5，料液比1:40 g/mL，酶解时间129 min，酶解温度53℃，加酶量0.4%。经此条件纯化的核桃粕蛋白的纯度可达到94.48%±1.83%。核桃蛋白的功能性质结果表明，中性条件下其溶解度为24.82%，吸水性3.06 g/g，吸油性3.15 g/g，乳化性16.10 m2/g，乳化稳定性为38.87 min，起泡性为30.53%，起泡稳定性为75.44%，在同一pH条件下，纯化后的核桃蛋白具有较好的功能性质。

Extraction and Purification Process Optimization and Functional Properties Analysis of Walnut Meal Protein

To obtain high-quality walnut meal protein, the process conditions for extraction of walnut meal protein by alkaline solubilization and acid precipitation method and purification of walnut meal protein by glycolytic enzyme were optimized by single-factor experiments and response surface method, respectively, and the functional properties such as solubility, water absorption, and emulsification were analyzed. The optimal extraction process conditions were: pH12, temperature 55 ℃, time 90 min, and material-liquid ratio 1:40 g/mL. Under these conditions, the extraction rate of walnut meal protein could reach 81.89%±1.64%, and its settling point was pH4.5. The optimal purification process conditions were: pH4.5, material-to-liquid ratio 1:40 g/mL, enzymatic digestion time 129 min, enzymatic digestion temperature 53°C, and enzyme addition 0.4%. The purity of walnut meal protein purified under these conditions could reach 94.48%±1.83%. The results of functional properties of walnut protein showed that its solubility was 24.82%, water absorption 3.06 g/g, oil absorption 3.15 g/g, emulsification 16.10 m2/g, emulsification stability 38.87 min, foaming 30.53% and foaming stability 75.44% under the same pH conditions, and the purified walnut protein had better functional properties.