甜菊糖苷-大豆分离蛋白复合体系的乳化性能研究

Emulsifying properties of the mixture of steviol glycosides and soy protein isolate

以葡萄糖基甜菊糖苷和天然甜菊糖苷中的斯替夫苷和莱鲍迪苷A为代表性甜菊糖苷,研究甜菊糖苷(SG)-大豆分离蛋白(SPI)复合乳化剂的乳化性能以及甜菊糖苷在溶液界面性能上的构效关系。实验发现,SG-SPI降低玉米油/水界面张力的作用与其稳定的玉米油-水乳液的稳定性之间存在关联效应。SG-SPI复合乳化剂相比于单一的SPI或SG,可明显提高玉米油-水乳液的热稳定性、pH稳定性与电解质稳定性。几种甜菊糖苷溶液降低表面张力的能力随其分子中葡萄糖基数的增加而增加,均比SPI具有更高的降低表面张力的能力。SG和SPI的复合使用对表面张力降低产生了正向协同作用。

With stevioside, rebauboside A and glucosylated steviol glycosides as the representative steviol glycosides, the interfacial activity and emulsifying ability of the mixtures of steviol glycosides(SG) and soy protein isolate(SPI), namely SG-SPI, were investigated. It was found that the decrease of the corn oil-water interfacial tension caused by SG-SPI has correlation with the stability of the emulsion system. Compared with SPI and SG solely used, SG-SPI can obviously improve the thermal stability, pH stability and electrolyte stability of the emulsion. The ability of SG in reducing surface tension, which is increased with the increase of the number of glucose residues, is more effective than that of SPI. SG and SPI present a positive synergistic effect on the decrease of surface tension.