Effect of different coagulants on yield and quality of tofu from soymilk

Soymilk tofu coagulated with four indigenous coagulants was compared in terms of chemical, textural, colour, and sensory attributes with calcium sulphate (CS) coagulated tofu. Coagulants used are Epsom salt (ES), lemon juice (LJ), alum and top water of fermented maize (TWFM). Protein and magnesium content significantly (P < 0.05) increased from 44.5 to 51.7 g/100 g and 252 to 324.6 mg/100 g, respectively, in soybean grain to soymilk. Calcium and magnesium contents increased and decreased significantly (P < 0.05) in tofu coagulated with CS and ES, respectively. Lightness (L) values were 86.3, 86.2, 77.8, 72.4 and 84.6, redness (a) values are 0.34, 0.21, 0.87, 1.05 and 0.32, and yellowness (b) values were 24.0, 23.9, 27.3, 20.3 and 23.4 for CS, ES, LJ, alum and TWFM. The hardness, chewiness and brittleness of textural properties of tofu were significantly (P < 0.05) affected by different sources of coagulation. Sensory evaluation data shows that LJ impacts a significantly acceptable sensory attribute to tofu. This study has demonstrated that tofu quality is affected by the type of coagulant used in curding the soymilk.