Effects of different coagulants on coagulation behavior of acid-induced soymilk

Divalent calcium ions can be used into the coagulation procedure of tofu-producing. The different calcium salts also have the difference coagulation process. This paper reports an investigation on the effects of counterions of calcium salts on the coagulation process of soymilk protein by the variation of viscosity. The same amount of Lactobacillus plantarum 70810 was added because of its acid reduction effects, which plays a synergistic effect with calcium salts. Coagulation process of soymilk containing various coagulants was characterized by viscosity under a shear rate of 2 s−1 at 37 °C. The textural properties and pH of tofu prepared from different coagulants were also determined. Results indicated that there are two successive first-order reactions by viscosity analysis, and the coagulation rate constant in the second stage was 4–6 times higher than that the first stage. The coagulation rate among the coagulants followed the anion series: formate > acetate > chloride > lactate. The textural properties also have correlation with the final viscosity of soybean milk mixture after 4.5 h coagulation, whereas the pH has nothing to do with the coagulants behaved. Evidence emerged that counterions of calcium source salts affect the coagulation process of soymilk protein. This fact clearly opens up many possibilities for soymilk coagulation.