Ma Wenjun, Qi Baokun, Sami Rokayya, Jiang Lianzhou, Li Yang, Wang Hui
College of Food Science, Northeast Agricultural University, Harbin 150030, China.
Department of Food Science and Nutrition, Taif University, Taif, Al-huwayah 888, Saudi Arabia.
Int J Anal Chem. 2018 May 23;2018:9182508. doi: 10.1155/2018/9182508. eCollection 2018.
The conformational and functional changes of soybean protein after a hybrid extrusion-hydrolysis method were evaluated. Three extrusion temperatures (60, 80, and 100°C) were used prior to enzymatic hydrolysis. The hydrolysis degrees, molecular weight profiles, solubilities, surface hydrophobicities, sulphydryl contents, disulfide bound, water holding capacity, emulsion, and foam properties of the protein isolated from the enzyme-hydrolyzed extruded soybeans were analyzed. It shows that extrusion caused significant changes in the hydrophobicity, molecular weight distribution, solubility, surface hydrophobicity, emulsification activity, and stability of the protein. The increase of molecular weights could be attributed to the formation of protein aggregates during extrusion. Extrusion and enzymatic hydrolysis led to a sharp increase in the number of disulfide bonds with a decrease of the sulphydryl group. The water holding capacity and the solubility of protein increased with the increase of extrusion temperature and hydrolysis time. Extrusion improved the emulsifying activity but reduced the emulsifying stability of the recovered proteins. Extrusion improved the foam capacity but reduced the foam stability of the proteins. The data demonstrated that the extrusion-hydrolysis treatment significantly altered the conformational and functional properties of soybean protein, which may be further optimized for the development of new soy protein ingredient with desired functional properties.
评估了大豆蛋白在混合挤压-水解法处理后的构象和功能变化。在酶解之前采用了三种挤压温度（60、80和100°C）。分析了从酶解挤压大豆中分离出的蛋白质的水解度、分子量分布、溶解度、表面疏水性、巯基含量、二硫键、持水能力、乳化和泡沫性能。结果表明，挤压导致蛋白质的疏水性、分子量分布、溶解度、表面疏水性、乳化活性和稳定性发生显著变化。分子量的增加可归因于挤压过程中蛋白质聚集体的形成。挤压和酶解导致二硫键数量急剧增加，巯基减少。蛋白质的持水能力和溶解度随着挤压温度和水解时间的增加而增加。挤压提高了回收蛋白质的乳化活性，但降低了其乳化稳定性。挤压提高了蛋白质的泡沫能力，但降低了其泡沫稳定性。数据表明，挤压-水解处理显著改变了大豆蛋白的构象和功能特性，这可能会为开发具有所需功能特性的新型大豆蛋白成分而进一步优化。
