Dry Tofu Characteristics Affected by Soymilk Solid Content and Coagulation Time¹

The effects of soymilk solid content (°Brix) and coagulation time on the yield, proximate composition, and textural characteristics of dry tofu were investigated. Soymilk °Brix significantly (p < 0.05) influenced tofu yield, fracturability, hardness, springiness, cohesiveness, and chewiness. Among soymilk °Brix of 7.1, 7.8, 8.4, and 9.2 tested, °Brix 9.2 (9:1 water/bean ratio) produced the lowest yield (201g/100g bean), but the highest fracturability, hardness, cohesiveness, springiness, and chewiness. Coagulation time for 5 min resulted in a significantly lower tofu yield but higher cohesiveness than coagulation for 15 min. The fracturability and hardness of tofu from 9.2 °Brix soymilk coagulated for 5 min were greatest (18.0 and 19.6 kg, respectively). Lower soymilk °Brix and longer coagulation time produced tofu with a significantly higher moisture content. Dry tofu contained approximately 75–78% moisture (wet basis), 55–58% protein (dry basis), and 20–23% fat (dry basis).