大豆分离蛋白对大豆肽纳米颗粒Pickering乳液性能的影响

Effects of soy protein isolate on the properties of Pickering emulsions stabilized by soy peptide nanoparticles

为提高大豆肽纳米颗粒(SPN)Pickering乳液稳定性,以大豆肽聚集体为原料,采用超声法制备SPN,对超声时间进行了优化;在SPN体系中引入大豆分离蛋白(SPI)构建复合乳化剂,研究不同乳化剂质量浓度下SPI对SPN界面活性和乳化稳定性的影响。结果表明:选取超声时间10 min制备SPN;随着乳化剂质量浓度的增大,乳液粒径逐渐减小,当乳化剂质量浓度较低(5 mg/mL)时,乳液出现桥联,乳化剂质量浓度过高(30 mg/mL)时则出现絮凝;界面蛋白吸附率随着乳化剂质量浓度的增加呈现先升高后降低的趋势。在相同乳化剂质量浓度下,添加SPI的SPN乳液(SPI-SPN乳液)的粒径分布峰左移,其粒径、界面蛋白吸附率显著小于SPN乳液的;在储存过程中,SPN乳液粒径逐渐增大,SPI-SPN乳液粒径没有显著变化;SPI-SPN乳液的乳析指数小于相同乳化剂质量浓度的SPN乳液,当乳化剂质量浓度为30 mg/mL时,储存15 d SPI-SPN乳液未出现分层现象。综上,SPI可以提高SPN的界面活性和SPN乳液储存过程中的絮凝稳定性和分层稳定性。

In order to improve the stability of the Pickering emulsion of soy peptide nanoparticles(SPN),soy peptide aggregates were used as raw materials to prepare SPN by ultrasonic method,and the ultrasonic time was optimized.And then soy protein isolate(SPI)was introduced into the SPN system to construct a new composite emulsifier.The effects of SPI on the interface activity and emulsification stability of SPN under different emulsifier mass concentrations were studied.The results showed that SPN was prepared under the condition of ultrasonic time 10 min.With the increase of emulsifier mass concentration,the particle size of the emulsion decreased gradually.When the emulsifier mass concentration was low(5 mg/mL),the emulsion bridged,while when the emulsifier mass concentration was high(30 mg/mL),the emulsion flocculated.The adsorption rate of interfacial protein increased chiefly and then decreased with emulsifier mass concentration increasing.Under the same emulsifier mass concentration,the particle size distribution peak of the SPN emulsion with SPI(SPI-SPN emulsion)was shifted to the left,and the particle size and adsorption rate of interfacial protein were significantly smaller than the SPN emulsion.The particle size of the SPN emulsion gradually increased during storage,while the particle size of the SPI-SPN emulsion did not change significantly.The creaming index of SPI-SPN emulsion was smaller than that of SPN emulsion with the same emulsifier mass concentration.The SPI-SPN emulsion did not appear to cream after 15 d of storage when the emulsifier mass concentration was 30 mg/mL.In conclusion,SPI can improve the interfacial activity of SPN and the stability of flocculation and stratification of SPN emulsion during the storage.