The effect of oyster shell powder on the extension of the shelf life of tofu

• Published in: Food chemistry 2007, Vol.103 (1), p.155-160
• Main Authors: Kim, Young Soon, Choi, Yang Mun, Noh, Dong Ouk, Cho, Seung Yong, Suh, Hyung Joo
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fish and seafood industries; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; oysters; powders; Sensory evaluation; sensory properties; Shelf life; shell (molluscs); Shell powder; Soybean curd; texture; Tofu
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2006.07.040

The effects of oyster shell powder addition (0%, 0.05%, 0.1% and 0.2% of soy milk) on quality and shelf life of tofu (soybean curd) were investigated. Yield and moisture of tofu prepared with 0.1% of shell powder were higher than that coagulated with a single use of MgCl 2. Syneresis was low when shell powder was added to tofu, but higher when MgCl 2 was added. Shell powder addition (0.05% and 0.2% of soymilk) showed a high level in hardness and gumminess comparing with tofu prepared with a single use of MgCl 2. However, there was no significant difference ( p > 0.05) between 0.05% and 0.2% addition of shell powder. When 0.05% of shell powder was added, overall acceptability showed a high score because tofu had a good mouthfeel, moderate firmness and lower beany-flavour. However, there was not a significant difference ( p > 0.05) between no addition and 0.05% and 0.1% addition of shell powder. Tofu prepared with shell powder (0.05% and 0.1% addition) had a shelf life of above 2 days longer than that prepared with a single use of MgCl 2. The addition of shell powder (0.05% and 0.1%) for tofu manufacturing resulted in a good sensory evaluation and the extension of shelf life.