天然和热处理大豆蛋白稳定乳液的性质研究

热处理(901、20℃)修饰的大豆分离蛋白用于制备水包油(O/W)乳液,并对天然和热处理蛋白乳液的粒径、微结构、絮凝率和分层稳定性进行表征。热处理蛋白的水力学半径随蛋白浓度和加热温度的增加而增加,证实了可溶性聚集体的产生。乳液粒径和分层稳定性受离子强度、聚集体粒径影响。低离子强度下(0 mmol/L),与天然蛋白相比,热处理蛋白乳液粒径较大,20 d放置后未发生分层。离子强度的增加(100mmol/L)导致天然蛋白乳液粒径明显增大;而热处理蛋白乳液则表现出较高耐盐性,体现在更小的粒径、絮凝率和分层指数。与90℃热处理相比1,20℃热处理减小了乳液液滴的粒径和絮凝。

Characterization of Oil-in-Water Emulsion Stabilized by Native and Heat-Treated Soy Protein

Heat treatments(90 and 120 ℃) were used to modify the emulsifying properties,and the droplet size,microstructure,and creaming stability of emulsion stabilized by native and heat-treated proteins were investigated and compared.Upon heat treatment,the hydraulic radius of protein gradually increased with increasing protein concentrations and heating temperature due to the formation of soluble aggregates.The droplet size and creaming stability of emulsion depended on ionic strength and degree of protein aggregation.At low ionic strength,heat-treated protein emulsion had higher droplet size as compared to native protein emulsion,without creaming after 20 day storage.The addition of salt(100 mmol/L) resulted in the increase in droplet size of emulsion,especially native protein emulsion.However,emulsion stabilized by heat-treated SPI exhibited a decreased salt sensitivity,as evidenced by lower droplet size,flocculation degree,and creaming index.Compared to heat treatment at 90 ℃,higher heating temperature(120 ℃) slightly decreased the droplet size and flocculation degree of emulsion.