• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.116-122
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• 1990

In order to improve the shelf life of Tofu, the effect of calcium chloride or acetic acid as coagulants were investigated for microbial and physicochemical changes during the storage in different kinds of soaking solution. The soaking water of Tofu prepared from calcium chloride was found to be spoiled after 15-17 hours of storage at $30^{\circ}C$, by reaching the bacteria count to 10million per ml. The shelf life of the Tofu prepared from acetic acid was better than those prepared by calcium chloride. For the effect of soaking solution on storage life, soaking Tofu in 0.1% acetic acid was found to be more effective than soaking in other solutions of 3% NaCl or 0.1% K-sorbate. The optical density of soaking solution of Tofu increased in proportion to spoilage, and in case of soaked Tofu in 3% sodium chloride and 0.1% K-sorbate solution, it greatly increased. Titratable acidity, and amino nitrogen contents in soaking solution increased as spoilage of Tofu progressed, but pH decreased the early period, one or two days, of stored Tofu and then increased.

• Food Science and Preservation
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• v.18 no.6
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• pp.961-966
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• 2011

This research was carried out to evaluate the value of tofu containing mushroom as a immunomodulator. Tofu was made using $CaSO_4{\cdot}2H_2O$ or Lactobacillus extract as a coagulant after adding powder of fruit bodies or mycelia of Letino edodes and Lepista nuda to soybean milk. Proximate compositions of tofu and tofu containing mushroom were analyzed. Levels of interferon ${\gamma}$ (IFN-${\gamma}$), interleukin 4 (IL-4) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in culture media of lymphocytes collected from mouse spleens after being injected with mushroom, regular tofu, or tofu made with mushroom were measured by sandwich ELISA. In addition, concentrations of IgG1, IgG2a and IgE in plasma or lymphocyte culture media were analyzed. Crude protein, crude lipid and crude ash were decreased in tofu containing mushroom but phosphorus was increased significantly. IFN-${\gamma}$ concentration was significantly decreased in mice injected with fruit body or tofu alone. IL-4 level was decreased significantly in mice injected with tofu containing fruit body of L. edodes. However, TNF-${\alpha}$ was increased in mice injected with tofu containing fruit body of L. edodes. Plasma levels of IgG1 were increased in almost all groups, while there was no significant change in IgG2a levels among treated mice groups. Concentrations of IgG1 and IgG2a were increased significantly in lymphocyte culture media of mice injected with tofu containing mushroom. Plasma levels of IgE level was significantly increased in mice injected with tofu or fruit body of L. edodes, but not in mice treated with tofu containing mushroom. These results showed that tofu with mushroom affected immune activities, and it seems valuable to consider developing the mixture of tofu and L. edodes as an immunomodulator.