不同11S/7S比值原料豆乳的乳液特性研究

为探明大豆蛋白11S/7S比值对豆乳乳液特性的影响,选取7个不同11S/7S比值(0.55~5.09)的大豆品种制备豆乳,并检测豆乳中蛋白溶解度、粒径、Zeta电位、豆乳粘度、游离巯基、表面疏水性和沉淀率等与豆乳乳液特性紧密相关的指标。结果表明:大豆中11S/7S比值较小时,豆乳中蛋白溶解度高,粒径小,豆乳粘度小,蛋白Zeta电位绝对值高,游离巯基含量多,表面疏水性高,豆乳沉淀率低,豆乳稳定性高。反之,大豆中11S/7S比值较大时,蛋白溶解度低,粒径偏大,豆乳粘度大,蛋白Zeta电位绝对值低,游离巯基含量少,表面疏水性低,造成豆乳沉淀率高,豆乳稳定性低。但当原料中11S/7S比值处于3.0~3.49时,各豆乳上述指标之间差异不显著(P>0.05)。

Emulsion Properties of Soymilk Prepared by Different 11S/7S Ratio Soybean

In order to explore the effect of protein 11S/7S ratio(0.55~5.09)in soybean on the emulsion properties of soymilk,7 soybean varieties with different 11S/7S ratio were selected to prepare soymilk. Protein solubility,particle size,zeta potential,soymilk viscosity,free sulfhydryl,surface hydrophobicity and precipitation rate in soymilk was detected respectively,which were closely related to the emulsion properties of soymilk. The results showed when the ratio of 11S/7S in soybean was low,the particle size and the viscosity of soymilk was low,the protein solubility,zeta potential absolute value,the free sulfhydryl contents,the surface hydrophobicity was separately high,which lead the low precipitation rate and high stability of soymilk. On the contrary,when the 11S/7S ratio in soybean was high,the particle size and the viscosity of soymilk was large,the protein solubility,zeta potential absolute value,the free sulfhydryl contents,the surface hydrophobicity of soymilk was low respectively,which induced the high precipitation rate and low stability of soymilk. However,when the ratio of 11S/7S in soybean was 3.0~3.49,there was no significant difference in the above indexes of soymilk(P>0.05).