温度和大豆分离蛋白质量浓度对其亚基的影响

Effects of temperature and mass concentration of soy protein isolate on its subunits

用差示量热扫描(DSC)和SDS-PAGE电泳分析研究了温度和大豆分离蛋白(SPI)质量浓度对其亚基的影响。结果表明:SPI经80℃热处理后,其上清液中11S的A-B亚基间的二硫键未断开;100℃热处理后,A-B因二硫键断开而解离。SPI热处理时,当质量浓度达到60g/L以上,B和β亚基几乎完全沉淀,而A、α′和α亚基通过二硫键相互作用形成可溶性聚集物。该研究结果可为SPI生产中的热处理提供一定的理论指导。

The effects of temperature and mass concentration of soy protein isolate （SPI） on its subunits were studied by DSC and SDS - PAGE. The results showed that the disulfide bonds of the A - B subunits of glycinin,located in the supematant fraction, were not broken after thermal treatment at 80 ℃. However, A- B dissociation occurred after thermal treatment at 100 ℃ because the disulfide bonds were broken. When the mass concentration of SPI in heating process was above 60 g/L, nearly all of the B subunits and β subunits were located in precipitates, whereas the A, α and α＇ subunits interacted through disulfide bonds to form soluble aggregates. These results can provide some theoretical guides for the thermal treatment in the production of SPI.