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Preparation of tofu using chitosan as a coagulant for improved shelf-life

No, H.K., Meyers, S.P.
International journal of food science & technology 2004 v.39 no.2 pp. 133-141
water content, tofu, soymilk, whey, chitosan, coagulants, molecular weight, solvents, acetic acid, lactic acid, coagulation, temperature, food processing quality, ash content, protein content, pH, shelf life, sensory evaluation, texture, hardness, color, turbidity, plate count
The potential of chitosan as a coagulant in commercial tofu preparation was investigated with six chitosans of different molecular weights using various treatments. The following optimum processing conditions for tofu preparation were proposed: chitosan with a molecular weight of 28 kDa; chitosan solution type, 1% chitosan/1% acetic acid; chitosan solution to soymilk ratio, 1 : 8; coagulation temperature, 80 °C; coagulation time, 15 min. However, the sensory quality of tofu was notably improved using a 1 : 1 mixture of 1% acetic acid and 1% lactic acid instead of 1% acetic acid alone as a chitosan solvent. Tofu prepared with chitosan had lower ash and higher protein content than those of commercial products tested. In storage tests, the chitosan-tofu had a longer shelf-life, about 3 days, than tofu made with CaCl2. This added shelf-life is significant in view of the magnitude (366 000 tonnes year-1) of tofu produced from commercial tofu plants (1407 plants as of 1998) in Korea.