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

• Published in: International journal of food science & technology 2004-02, Vol.39 (2), p.133-141
• Main Authors: No, Hong Kyoon, Meyers, Samuel P.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chitosan solvent; coagulation; colour; Food industries; Fundamental and applied biological sciences. Psychology; hardness; molecular weight; sensory evaluation
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1046/j.0950-5423.2003.00772.x

Summary 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.