• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.190-196
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• 2009

To optimize the mixing ratio of ingredients for optimal sensory qualities of seasoned tofu, a response surface methodology with a central composite design was performed on tofu containing freshwater crab meat (TCM). Using the desirability function technique, the optimal formulation was determined to be 3.67 g of freeze dried meat, 5.54 g of garlic powder, and 2,120 mL of soymilk. In the texture profile analysis, tofu prepared using the optimal ingredient ratio had a higher hardness, cohesiveness and gumminess than commercial tofu but TCM value for adhesiveness, springiness and chewiness were lower. However, the texture properties of TCM were not significantly different than those of commercial tofu.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.580-584
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• 2009

The effect of freshwater crab meat additive on protein quality of tofu was studied. Tofu containing freshwater crab meat(TCM) prepared by the formulation for the best sensory qualities had about 20% more lipid and ash content than those of commercial tofu. TCM showed a higher content of lysine, methionine, cysteine and tyrosine compared with those in commercial tofu. TCM was comparable to commercial tofu(CT) regarding the in vitro protein digestibility(95%). A considerable difference in computed protein efficiency ratio(C-PER) resulted between CT(1.76-1.81) and TCM(2.61). Therefore, crab meat has potential as an ingredient for enriching essential amino acid and improving protein quality of CT.

• Preventive Nutrition and Food Science
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• v.10 no.3
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• pp.224-230
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• 2005

The effects of low viscosity chitosan on the rheological properties of soymilk using a model system and on tofu qualities were examined. The flow behavior of soy milk with chitosan closed the Newtonian flow and stabilized according to increasing chitosan concentration. The soymilk containing $glucono-\delta-lactone$ exhibited a more pseudoplastic flow behavior compared with that of the control soymilk. The addition of low viscosity chitosan to the tofu preparation did not significantly affect its physicochemical properties. However, the results of the TEM image and instrumental textural properties showed that low viscosity chitosan affected the construction of the tofu structure. Chitosan tofu had low scores across the whole field of appearance in the sensory evaluation, and its overall eating quality was scored significantly lower. These results suggest that the addition of low viscosity chit os an affects the quality of tofu, which changes according to the degree of polymerization and concentration of chitosan.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.74-80
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• 1999

Growth and bacteriocin production by Lactobacillus sp. GM7311 in tofu residue treated with two commercial amylases were investigated. The optimal condition of amylase Ⅰ(liquefied enzyme for sauce) and Ⅱ(multienzyme 2,000) for the enzyme reaction was showed at pH 6.0 and 4.0, respectively. The optimal temperature was 40oC both. At the enzyme dosage 4% and 3% and reaction time 1hr, about 2% of reduced sugar needed bacteriocin production was obtained. The enzymatic treatment of tofu residue enhanced bacteriocin production by lactic acid bacteria, particularly in the tofu residues added 2.0% yeast extract. But, we couldn't see the increment of bacteriocin activity in the tofu residues added other nitrogen sources such as proteose peptone No. 3 and lab lemco powder. Also, in the comparision of amylase I and Ⅱ, bacteriocin activity in the tofu residue treated with amylase Ⅰ was better than that of amylase Ⅱ.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.90-97
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• 1994

Effect of addition of oil , sucrose, dextrin and oil-sucrose (1 : 1 w/w) mixture on SPI tofu was investigated. The characteristics measured were yield , water holding capacity , textural and organoleptic properties. THe SPI tofufwas prepared by coagulation of soyprotein isolate (SP) suspensino by CaCl$_2$ , CaSo$_4$ an dGDL , followed by compression . Addition of oil to SPI increased the tofu yield and water holding capacity, particulary for those tofu coagulated by CaCl$_2$. Eventhough dextrin addition decreased the yield, it showed the most improving effect on water holding capacity. The tofu prepared by CaSO$_4$coagulant resulted highest in yield and water holding capacity. Hardness was found to be decreased as the oil, sucrose and dextrin added more and adhesiveness, cohesiveness and guminess were also affected. The sensory evaluation showed the SPI tofu prepared by CaSO$_4$ and 10% addition of oil and sucrose mixture to be realtively high in hardness , elasticity and uniformity of the texture.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.4
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• pp.465-471
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• 2014

This study investigated the quality characteristics of tofu prepared with Boehmeria nivea powder. Moisture, crude ash, carbohydrate, crude protein and crude lipid contents were 7.71%, 20.09%, 39.01%, 31.25% and 0.93%, respectively. The yield of tofu added with BNP increased with addition of BNP, However, there was a significant decrease in pH as well as a significant increase in total acidity. In addition, L, a and b values of tofu decreased with increasing content of BNP. In terms of textural properties, hardness, chewiness and brittleness increased, whereas springiness and cohesiveness decreased, with increasing addition of BNP. In the sensory evaluation, overall preference for tofu added with 0.6% BNP was the highest. According to the results, addition of BNP positively affects the overall sensory evaluation of tofu, and 0.6% is the optimal level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.412-419
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• 2004

To investigate the utilization of calcium lactates (CaL) as coagulants for tofu manufacture, the quality characteristics and shelf-life of tofu made by CaL-P (black snail powder) and CaL-A (black snail ash) were investigated and compared to calcium chloride (CC), magnesium chloride (MC), calcium sulfate (CS ) and standard calcium lactate (CaL-S). And also, total microbe and turbidity of the tofu were determined during storage at 1$0^{\circ}C$. Coagulation ability of CaL-A was the highest, and the ability of CaL-P was higher than that of CaL-S. Yield of CaL-A tofu was similar to those of CS and CC tofu, while the yield of CaL-P tofu was 50% compared to that of CC. L＊ value of CaL-P tofu was lower, but a＊ and b＊ values were higher than those of other tofus. The hardness of tofu showed in the order of CaL-S>CS>CC>CaL-P>MC>CaL-A, while the cohesiveness showed in the order of MC>CaL-S>CC>CS>CaL-P>CaL-A. Calcium contents were 57 mg% in MC tofu, 174 mg% in CS tofu, 116 mg% in CaL-S tofu, 95 mg% in CaL-A tofu and 172 mg% in CaL-P tofu. From the results of microscopic observations, the lower hardness showed the more soft and the smaller particle. The particle of CaL-A tofu was small and uniformity but the size of CaL-P and CC tofu showed coarse. Sensory quality of CaL-P and -A tofu were better than the other tofu evaluated by texture, springiness, flavor and overall taste. The shelf-life estimated by total microbe was 4∼6 days in CC, MC, CS, CaL-S and CaL-A tofu, but 8 days in CaL-P tofu at 1$0^{\circ}C$. From the above results, the CaL-P and -A may believe to use as coagulant for tofu manufacture due to its softened taste and enhanced shelf-life, and higher calcium content which has higher absorbability in human body.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.458-463
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• 2007

This study was carried out to investigate potential use of Scutellaria bicalensis Georgi (SBG) as an ingredient for extending the shelf life of tofu. The spore of Bacillus sp. KN-4 was isolated from commercial tofu and inoculated to soybean milk to prepare artificially contaminated tofu. The contaminated tofu was stored in the presence of 0.05 and 1% of SBG extract at $25^{\circ}C$ for 72 hrs. The pH changes of contaminated tofu with SBG extract was slower than those of control during storage. The degree of pH change decreased as the concentration of SBG extract was increased from 0.05% to 0.1%. The change of titratable acidity of the tofu showed the same tendency as pH change during storage. Total cell number of the SBG extract added tofu was lower about $1{\sim}2$ log cycle (0.05% SBG extract) or $2{\sim}3$ log cycle (0.1% SBG extract) than that of control after storage for 12 hrs at $25^{\circ}C$. The color changes of the tofu did not show any difference with and without SBG during storage at $25^{\circ}C$. The strength and hardness of the tofu was improved by the addition of SBG extract. Especially, the strength and hardness of tofu in the Presence of 0.1% SBG extract did not change during storage time. The sensory Qualify of SBG extract added tofu was better than control in texture, but not in taste and color. The overall acceptability of the SBG extract added tofu was similar to control.

• 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.