• Korean journal of food and cookery science
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• v.20 no.2
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• pp.144-150
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• 2004

This study was conducted to investigate the quality characteristics and shelf-life of tofu added with basil water extract (BWE). BWE was selected from 11 kinds of herbs based on estimations of antimicrobial activity, taste and flavor. The amount of waster was 7 times greater than that of raw soybean, BWE concentration against soybean juice was 20 mg% and GDL concentration was 0.3% as the optimal preparation conditions of tofu added with BWE (BWE-tofu). Color L＊, a＊ and b＊ values of BWE-tofu were 78.11, 0.78 and 19.10, respectively, indicating that light green color was lower in the L＊ value, and higher in the at and b＊ values compared to control products. Savory taste and overall acceptability of the tofu were higher than those of control products evaluated by sensory test. Shelf-life of the tofu at 10$^{\circ}C$ was 8 days, which was prolonged by 4 days compared to control products evaluated by pH, titratable acidity and total microbes.

• Food Science and Preservation
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• v.12 no.6
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• pp.516-521
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• 2005

Effect of chitosan on shelf life of soybean tofu was investigated. The quality changes of soybean tofu drained after immersion in $0.1\%$ chitosan solution for 1 hr were examined during storage at 10, 20 and $30^{\circ}C$. The number of viable cell of soybean tofu with treated chitosan was lower about 1 log cycle than that of control after 2 days storage at $10^{\circ}C$ and $20^{\circ}C$, although there was no detectable differences at $30^{\circ}C$. pH decrease during storage soybean tofu at $10^{\circ}C$ was begun after 4 days in soybean tofu with treated chitosan, while 3days in control. Hardness of soybean tofu with treated chitosan was maintained higher than that of control over the storage period at $10^{\circ}C,\;20^{\circ}C\;\and\;30^{\circ}C$. Shelf life of soybean tofu with treated chitosan was extended about 1 day at $10^{\circ}C$ compared with control.

• 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.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.502-510
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• 2007

This study investigated the utilization of turmeric (Curcuma aromatica Salab.) for tofu manufacture and its effects on the quality characteristics and shelf-life. Various concentration (0.000%, 0.005%, 0.010%, and 0.015%) of turmeric were used to evaluate the shelf-life during tofu storage for 12 days at $10^{\circ}C$. The pH decreased with an increasing storage period, but the 0.010% and 0.015% tofu showed lower pH value than the 0.000% tofu, the acidity decreased with an increasing storage period. The water content of the turmeric tofu decreased with an increasing storage period. The turbidity gradually increased until 6 days of storage, and then rapidly increased at 12 days of storage. The microbial count of the 0.015% tofu was lowest during the storage period. In measuring the turmeric tofu color, the L- and a--values decreased during the storage period, while the b--value increased. In the texture analysis, hardness, gumminess, and brittleness of the turmeric tofu decreased 12 days of storage. Cohesiveness and springiness increased with an increasing storage period. In the sensory evaluation, Smoothness, after taste, and overall taste were highest for the 0.010% tofu. For the overall acceptability, the 0.010% tofu (with 0.45% mixed coagulant) attained the highest score.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.3
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• pp.345-352
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• 2008

This study investigated the utilization of tofu stake with turmeric manufacture by analyzing its effects on quality characteristics and shelf-life of tofu made with 0.5 CT(0.5% turmeric power), 1.0 CT(1.0% turmeric power), 1.5 CT(1.5% turmeric power), and 2.0 CT(2.0% turmeric power) in comparison with those ST(standard), In color lightness tofu stake springiness decreased with increasing turmeric power content, while cohesiveness was higher than ST. The gumminess of tofu stake decreased with increasing turmeric power content, while brittleness was higher than ST. Water content of turmeric power tofu stake was higher than ST. Weight of tofu stake increased with increasing turmeric power content, while cooking loss decreased with increasing turmeric power content. Thiobarbituric acid content of turmeric power tofu stake decreased with increasing turmeric power content. For overall acceptability, $0.5{\sim}1.0%$ turmeric power tofu stake attained the highest score.

• Journal of the Korean Society of Food Culture
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• v.21 no.6
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• pp.644-652
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• 2006

This study was investigated the utilization of pomegranate(P) as coagulants for 새려 manufacture, the quality characteristics and shelf-life on tofu made by P1(fruit juice of pomegranate 1%) and P2(fruit juice of pomegranate 2%) and P3(fruit juice of pomegranate 3%) and P4(fruit juice of pomegranate 4%) and P5(fruit juice of pomegranate 5%) were investigated and compared to G.D.L(C). And also, total microbe and tatal acid of the tofu were determined during storage at $0^{\circ}C^$. The results are summarized as follow P3(493.3g/500ml) compared to C(485g/500ml) showed the highest yield. Turbidity of tofu was increased as the proportion of pomegranate was increased, while pH of tofu was increased as the proportion of pomegranate was decreased. $L^{\ast}^{\ast}^{\ast}$ value of C tofu was highest, $a^{\ast}^{\ast}^{\ast}$ value of tofu was increased as the proportion of pomegranate was increased and $b^{\ast}^{\ast}^{\ast}$ value of C tofu was higher than those of other tofus. The hardness of tofu coagulated with pomegranate showed higher than that of coagulated G.D.L. The cohesiveness of P4, P5 showed higher than C tofu, but those of other tofus showed lower than C tofu. The springiness of tofu showed in the order of P4>P5>P3>P2>P1, gumminess of P5 tofu was highest. The Brittleness of tofu was increased as the proportion of pomegranate increased. The pH value of tofu coagulated with pomegranate increased during storage at $0^{\circ}C^$. During the storage period of tofu, pH and total acid showed a maximum change in C tofu. Generally the total plate counts of bacteria of all tofu increased during storage at $0^{\circ}C^$, and those of tofu with added pomegranate were shown to be lower than C tofu. The results of S.E.M(scanning electron microscopes), the lower hardness showed the more soft and the smaller particle, The particle of C tofu was small and uniformity but the size of P4, P5 tofu showed coarse. In the sensory evaluation of all tofu, sleekness, nutty, chewiness and smoothness, appearance and overall quality was the highest in C tofu. In the sensory evaluation of tofus coagulated with pomegranate. overall quality was the highest in P2.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.746-749
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• 2002

From 7 different medicinal herbs, Rubus coreanus miquel, Therminalia chebula Retz and Rhus javanica was selected by paper disk method against 10 different microorganisms. The ethanol extracts of selected herbs was added into Tofu, and the total viable cell counts was determined. After 4 days, total viable cell count reached to $10^7$ and the Tofu putrefacted. The tested sample added with 0.01% of Terminalia Chebula Retz extract, the shelf-life was extended as 108.8%, with 0.05% was 117.3% and with 0.1% was 132.6%. Among 3 kinds of medicinal herb, Therminalia chebula Retz has better powerful activity than others.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.11-15
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• 2009

Commercial tofu was cut and re-packed in a vacuum container, an airtight container and an open tofu tray in an effort to assess the effects of vacuum containers on the shelf life of leftover tofu. The re-packed tofu were stored at $5^{\circ}C$ and $25^{\circ}C$ for the enumeration of total bacteria and coliforms. We also measured changes in color, pH, and opacity. The vacuum retarded the bacterial growth under $10^5$ CFU/mL for up to 12 days at $5^{\circ}C$. The color of the tofu was unaffected by the container type at both storage temperatures, whereas the pH and opacity of the immersion solution were altered less profoundly by storage in the vacuum container at $5^{\circ}C$. However, we noted no significant differences in bacterial growths, pH, and opacity among container types at $25^{\circ}C$. The results of this study showed that the usage of vacuum containers may be a favorable method for the preservation of tofu under refrigerated conditions.

• Journal of Dairy Science and Biotechnology
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• v.38 no.4
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• pp.222-229
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• 2020

This study was conducted to develop a novel cheese tofu hybrid product by increasing the calcium content of cheese, an animal protein source, and tofu, a vegetable protein source. Both pH and moisture were lower in the cheese tofu hybrid than those values in the control group (6.03% and 72%, respectively). Protein and fat were slightly higher than in the control (15.43% and 9.91%, respectively). Total bacteria count increased at the end of the product's shelf life, but did not affect its texture. The cheese tofu hybrid displayed stronger a) red, and b) yellow coloration than the control, and its lightness (L) was lower than that of the control. The cheese tofu hybrid possessed high hardness, and displayed high values for gumminess and brittleness. Sensory evaluation by a specialized agency examined consumer preferences, purchase intentions, strengths, and weaknesses of the developed product line. A panel of 30 female volunteers in their 20s and 40s recorded an overall preference for cheese tofu of 5.40 points, fairly good. Cheese tofu was found to be better than the control tofu, with appealing differences in appearance, color, nutty aroma, chewiness, and cheese flavor.