• Food Science and Preservation
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• v.10 no.1
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• pp.41-46
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• 2003

To prove the extension of shelflife of soybean curd(Tofu) steeped in the diluted solution of botanical antimicrobial agent and stored at 20$^{\circ}C$, such chemical ＆ microbial properties as the contents of moisture, crude protein and crude fat, colony count and surface color of Tofu were investigated in comparison with the control. Tofu treated with botanical antimicrobial agents showed higher contents of moisture, crude protein and crude fat compared to those of the control Tofu through all the storage period. After 7 days of the storage period, cell count of coliform bacteria reach 75 x 103CFU/m1 in the control Tofu, whereas 13∼39 CFU/ml in Tofu treated with botanical antimicrobial agent Treatment of Tofu with botanical antimicrobial agent seemed to be a potential method to prolong the shelflife of processed Tofu.

• Food Science and Preservation
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• v.18 no.5
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• pp.678-683
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• 2011

The effects of coagulant types (magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone) on yield, quality properties and storability of astringent persimmon powder added tofu were investigated. Yield, hardness, chewness, crispness, and overall acceptability of tofu coagulated by glucono-${\delta}$-lactone were higher than those coagulated by the others. L value, a value, pH, soaking-solution turbidity, and total aerobic bacteria of glucono-${\delta}$-lactone coagulated tofu were lower than those coagulated by the others. Calcium sulfate and calcium chloride coagulated tofu showed relatively high L and b values. Magnesium chloride coagulated tofu had higher sensory score for firmness, taste, overall acceptability than calcium chloride and calcium sulfate coagulated tofu, but there was no significant difference between magnesium chloride and glucono-${\delta}$-lactone. The results suggested that glucono-${\delta}$-lactone and magnesium chloride were found to be the suitable coagulants for processing of the persimmon powder added tofu.

• 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.

• Food Science and Preservation
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• v.23 no.6
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• pp.832-838
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• 2016

The purpose of this study was to investigate the effect of a fresh chlorella powder on yield, quality and self-life of organic soybean tofu. After added with a fresh chlorella powder, yields, physical properties, color, shelf-life and sensory properties of the organic soybean tofu added with chlorella powder was compared to the properties of soybean tofu. The yield of soybean tofu increased with the addition of more than 1% chlorella powder. Hardness of the organic soybean tofu with chlorella significantly increased compared to that of the soybean tofu. However, Hunter's color values of L, a, and b decreased by increases in the chlorella powder concentration. Total microbial population of the soybean tofu was higher than that of the organic soybean tofu with chlorella. However, pH of chlorella tofu decreased during storage period at $4^{\circ}C$. After 7 days storage at $4^{\circ}C$, the total microbial population decreased significantly with the addition of 2% chlorella powder. The L and a value of chlorella tofu was increased. On the other hand, the b value of chlorella tofu was decreased during storage. The results revealed that a fresh chlorella powder was a useful material to improve yield, quality and storage condition of the organic soybean tofu.

• Food Science and Preservation
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• v.21 no.2
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• pp.215-223
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• 2014

The quality characteristics and antioxidant activity of three kinds of tofu made from lipoxygenase (LOX)-free genotypes soybeans were compared to the Taekwang (LOX-present) tofu as the control. The mineral contents of Jinyang tofu were significantly higher than those of the control. The hardness and gumminess of tofu made from LOX-free genotypes were significantly higher than those of the control. Gaechuck#2 tofu showed higher sensory evaluation results than the other kinds of tofu in terms of taste, flavor and overall acceptability. The total isoflavone contents were higher in the LOX-free genotypes than in the control. The total phenol content was similar for the Gaechuck#1, #2 and Taekwang tofu. The flavonoid content was higher in Gaechuck#1 and #2 tofu than in the control. The antioxidant activities were the highest in Gaechuck#1 tofu, followed by the Gaechuck#2. During the 15-day storage at $4^{\circ}C$, the turbidity of the immersing water tended to increase, but Gaechuck#1 and #2 tofu were significantly lower than in the control after 15-day storage. Therefore it is suggested that Gaechuck#2 tofu could be the suitable genotype for tofu products because it is the most effective in terms of overall acceptability, antioxidant activity, and storage stability.

• Food Science and Preservation
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• v.20 no.4
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• pp.495-501
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• 2013

The principal objective of this study was to determine the quality characteristics of a tofu (soybean curd) with added Lagocephalus lunaris powder (LLP). The moisture, crude ash, crude protein, and crude lipid contents of the used LLP were 6.20%, 1.04%, 74.55%, and 1.20%, respectively. The yield and turbidity of tofu increased according to the increase in the quantity of LLP, whereas the pH decreased with the increase in LLP. The L value decreased as the amount of LLP in the formulation increased, whereas the a and b values of the tofu increased. Furthermore, the hardness, chewiness, and brittleness significantly increased as the level of LLP increased. In terms of overall acceptability, the preferred tofu samples contained 0.5% LLP. These results suggest that the LLP can be applied to tofu (soybean curd) in order to achieve high quality and functionality.

• Food Science and Preservation
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• v.20 no.5
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• pp.636-642
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• 2013

Quality and sensory characteristics of tofu prepared with concentrated to 8 $^{\circ}Brix$ deep ground sea-like water (SW) were investigated to check the availability for coagulants. The tofu was coagulated with three kinds of commercially coagulant, such as $MgCl_2$, $CaSO_4$ and glucono-${\delta}$-lactone. Different amounts of SW and soybean milk were added: SW-20 g/L, SW-25 g/L and SW-30 g/L. The moisture content and pH were significantly lower in which preparation with glucono-${\delta}$-lactone coagulated tofu, and others has not significantly difference each other. The mineral contents in the coagulant influenced the mineral content of the tofu, which contained larger quantities of major minerals. However, the mineral content of the tofu was not affected of the mineral concentration in the coagulant. The L and b values of the tofu prepared with SW were not significantly different. The hardness of the tofu prepared with the commercial coagulants was significantly lower than that of the tofu produced with the SW. The sensory property was lower when the hardness was lower and higher. In conclusion, the quality characteristics of SW-prepared tofu were not significantly different from those of the tofu prepared with the commercial coagulants, but the texture and the taste of the SW-prepared tofu were excellent.

• Food Science and Preservation
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• v.14 no.2
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• pp.136-141
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• 2007

The effects of various concentrations (0.01% 0.02% both v/v) of a Turmeric (Curcuma aromatica Salab.) ethanol extract (CE) on the shelf life of tofu were investigated during tofu storage for 12 d at $25^{\circ}C$. The total number of bacteria in tofu containing 0.02% CE was ca. 100 1,000-fold lower than that of the control after this period Tofu containing CE had a lower pH then did control curd, but was higherin titratable acidity, during the storage period. Measurement of hardness, cohesiveness, and springiness of tofu containing CE were higher than those of control during storage. Each of these parameters of texture value improved (increased) with an increase in the concentration of CE in tofu The degree of whiteness of tofu did not differ between samples with or without CE. The yellowness of tofu increased after addition of CE. The overall acceptability of tofu containing CE was lower than that of control.

• Food Science and Preservation
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• v.24 no.7
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• pp.942-948
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• 2017

To establish manufacturing technology of tofu shake added with red rice prepared with Monascus purpureus KCCM 60570, the quality characteristics of tofu shake added with M. purpureus KCCM 60570 were investigated. Also, we determined the optimal mixing ratios of raw materials including red rice for manufacturing tofu shake. Monacolin K and mold number of red rice were increased rapidly until $8^{th}$ day of incubation and then gradually increased during the 12 day manufacturing period. As the results, it was considered to be most suitable to prepare red rice for 8 days at $25^{\circ}C$, and inoculate 1% (w/w) M. purpureus KCCM 60570. Sensory evaluation of tofu shake added with red rice and tofu shake without red rice was not significantly different at p<0.05. In sensory evaluation, tofu shake added with 0.5% (w/w) red rice was higher in taste, texture, and overall acceptability than the other. Therefore, the optimal mixing ratio of red rice and tofu shake is 0.5% (w/w). These results suggest that the addition of red rice could improve the quality of tofu shake.

• 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.