Use of Natural Coagulants of Plant Origin in Production of Soycurd (Tofu)

Tofu - Soycurd, is one of the important non-fermented soybean products, which has been widely used in a variety of dishes by oriental people for many centuries. Normally in the preparation of Tofu, synthetic coagulants such as calcium sulphate, magnesium chloride, Glucono-delta-lactone, etc., are used. These coagulants are not readily available sometimes for use in the household and not available easily in the rural areas. Hence, an attempt was made to use natural coagulants of plant origin (Citrus lemon, Garcinia indica, Tamarindus indica, Averrhoa carambola, Averrhoa bilumbi, Phyllanthus distichus, Tamarindus indica flower extract, Hibiscus canabinus and Passiflora edulis) in preparation of Tofu. Yield, texture, proximate composition and sensory quality of Tofu prepared using natural coagulants were analyzed and a comparative evaluation was made between Tofu obtained from synthetic coagulants. Results showed that use of natural coagulants in preparation of Tofu increased the yield (24.5g/100 ml of soymilk). Total crude protein estimation revealed that the protein content in Tofu prepared using natural coagulants was comparatively higher than the synthetic coagulants (61.4% on dry weight basis). Texture analysis results of Tofu prepared using different coagulants showed that Garcinia indica extract produced Tofu with hard texture, more cohesiveness and chewiness compare to other coagulants followed by Calcium sulfate and Tamrindus indica. Sensory analysis of Tofu showed Citrus lemon extract produced best Tofu with higher overall quality in terms of appearance, texture, taste, flavor and color followed by Tamarindus indica.