Stabilization of soy milk using konjac glucomannan

A novel compound functional plant beverage could be formed by blending soy milk with konjac glucomannan (KGM), a beneficial polysaccharide. Both the phase behavior and the stability of KGM-soy milk blend system were studied. The phase diagram showed that the KGM-soy milk blend system could form three regions: i.e., Unstable zone, metastable zone and stable zone. The stability of the blend system was investigated by measuring turbidity, viscosity, Zeta potential, particle size and differential scanning calorimetry (DSC), respectively. The microstructure of the KGM-soy milk mixed system was characterized by confocal laser scanning microscope (CLSM), which indicated that KGM and soy milk could be evenly dispersed under certain conditions. The mixtures with relatively low KGM component were unstable and easy to sedimentation. However, the blend systems with high KGM component were relatively stable and were not easy to occur phase separation. The results implied that KGM could act not only as a functional ingredient, but also as a stabilizer in the compound plant beverage.