• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.3
• /
• pp.386-391
• /
• 2012

The principal objective of this study was to evaluate the quality characteristics of black garlic milk tofu prepared with five different levels (0%, 0.5%, 1%, 1.5%, and 2.0%) of black garlic concentrate (BG0~BG4). We conducted the pH, total phenol and flavonoids, Hunter's color values, mechanical characteristics, and a sensory evaluation analysis of black garlic milk tofu. The total phenol and flavonoid content of black garlic concentrate were 1.67mg/100 g and 1.07 mg/100 g. The more black garlic concentrate increased, the more lightness (L) decreased, but redness(a) and yellowness (b) increased. The hardness, gumminess, and chewiness scores significantly increased (p<0.05) in all black garlic milk tofu samples. In color, taste, flavor, texture, and overall quality, the score of milk tofu with 1.0% black garlic concentrate (BG2) increased the most.

• Journal of the East Asian Society of Dietary Life
• /
• v.19 no.2
• /
• pp.231-237
• /
• 2009

The principal objective of this study was to determine the quality characteristics of tofu prepared with the addition of skate (Raja kenojei) powder. The moisture, crude ash, carbohydrate, crude protein, and crude lipid contents of the used skate powder were 5.34%, 14.15%, 1.90%, 76.60%, and 2.08%, respectivly. The yield rate of the tofu did not differ significantly with the level of added skate powder; however, significant reductions in pH and a significant increase in acidity were observed. The L and b values of the tofu decreased with increases in the amount of added skate powder in the formulation, whereas the a values increased directly with the amount of added skate powder. Furthermore, hardness was increased significantly as the level of skate powder increased. In terms of overall acceptability, the preferred tofu samples were the control and the group to which, 1.0% skate powder was added.

• Journal of the East Asian Society of Dietary Life
• /
• v.19 no.5
• /
• pp.743-749
• /
• 2009

This study was conducted to investigate the quality characteristics of tofu prepared with the addition of shrimp powder. Moisture, crude ash, carbohydrate, crude protein, crude lipid of the used shrimp powder were 3.81%, 0.70%, 42.15%, 49.36%, and 3.98%, respectivly. The yield rate of the tofu did not differ significantly according to the level of added of shrimp powder, however there was a significant decrease in pH and a significant increase in acidity. The L and b values of the tofu were decreased as the amount of shrimp powder in the formulation increased, whereas the a values was increased. Furthermore, hardness was significantly increased as the level of shrimp powder increased. In terms of overall acceptability, the preferred tofu samples were the control and that containing 2.0% shrimp powder addition group.

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

• Journal of the East Asian Society of Dietary Life
• /
• v.20 no.5
• /
• pp.769-775
• /
• 2010

Quality characteristics and antioxidant activity of spirulina with added tofu were investigated in the presence of different coagulants ($CaSO_4$, $MgCl_2$, Glucono delta lactone (GDL), vinegar). The yield of the spirulina tofu was the highest when coagulated with GDL. The pH of spirulina tofu with $MgCl_2$ was the highest compared to those of other coagulants. The tumidity of spirulina tofu was the highest with $MgCl_2$. In the color analysis of spirulina tofu, the L (lightness) value was the highest with $CaSO_4$, whereas a (redness) value was the highest with $MgCl_2$. C-phycocyanin contents were the highest with the $CaSO_4$. Phycoerythrin of spirulina tofu for vinegar was 0.194 mg/mL, and GDL content was 0.214 mg/mL. Additionally, the antioxidant activity of spirulina tofu was the highest with $MgCl_2$ $IC_{50}$ values of the DPPH radical scavenging activity of spirulina tofu with $MgCl_2$ was 89.2 mg/g, GDL 93.5 mg/mL, $CaSO_4$ 116.7 mg/mL, and vinegar 118.0 mg/mL. The texture analyses (TPA) results showed that hardness was in the order of vinegar>$MgCl_2$>GDL>$CaSO_4$. For the overall acceptability of the preference test, the spirulina tofu that was made using $MgCl_2$ coagulant had the highest score. Based on these results, it is suggested that $MgCl_2$ is the proper coagulant for the preparation of spirulina with added tofu.

• The Korean Journal of Food And Nutrition
• /
• v.33 no.5
• /
• pp.576-583
• /
• 2020

The purpose of this study was to compare the quality characteristics of silken tofu products from the commercial market in Korea. Seven types of commercial silken tofu were sampled and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity, moisture contents (total solid contents), crude protein and fat contents were evaluated. The TPA results suggest that the texture of silken tofu was very different from one another according to the type of and the amount of coagulant. The commercial silken tofu showed a range of pH 5.53~6.48, total acidity of 0.12~0.32%, soluble solid contents of 2.62~5.07 °Brix, salinity of 2.28~4.30%, and moisture contents of 87.10~92.24%, respectively. In terms of the coagulant of tofu, besides the GDL (glucono-δ- lactone), other coagulants such as MgCl₂ for making 'silken tofu' in the Korean tofu market. The quality characteristics differed depending on the constituents of sample and the coagulants of tofu used. These results are expected to be useful in identifying new trends in the domestic silken tofu industry.

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

• Journal of the Korean Society of Food Culture
• /
• v.28 no.5
• /
• pp.495-501
• /
• 2013

The quality characteristics of tofu added Ligularia fischeri powder (LFP) were investigated. The proximate composition of LFP used was as follows: moisture, 7.7%; crude protein, 12.0%; crude lipid, 5.9%; crude ash, 14.1%; and carbohydrate, 60.3%. The yield of tofu added LFP increased with the addition of LFP. However, there was a significant decrease in pH (from $6.03{\pm}0.11$ in the control to $5.78{\pm}0.11$ when 0.4% LFP was added) and a significant increase (from $2.60{\pm}0.01$ in the control to $2.85{\pm}0.10$ when 0.4% LFP was added) in total acidity. In addition, the L, a, and b values of tofu decreased with the increasing addition of LFP. In terms of textural properties, the hardness, cohesiveness, and brittleness increased, whereas springiness decreased, with the increasing addition of LFP. In the sensory evaluation, the overall preference for tofu added 0.3% LFP was the highest. According to the results, the addition of LFP positively affects the overall sensory evaluation of tofu, and 0.3% is the optimal level for addition.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.2
• /
• pp.77-83
• /
• 2008

This study investigated the quality of tofu prepared by treating soybean milk with deep seawater as a coagulant. The quality and shelf-life of the tofu prepared using the deep seawater coagulant were determined and compared to those using $CaSO_4$, surface seawater, and intermediate seawater coagulant. The tofu made with the deep seawater coagulant was firmest. In addition, the deep seawater tofu product had more, smaller particles in the microscopic view, compared to the tofu made from surface and intermediate seawater coagulants. The deep seawater tofu product had the lowest viable cell counts and turbidity. In addition, the deep seawater tofu product had a longer extended shelf-life. From these results, deep seawater appears to improve the texture, taste, and shelf-life of tofu when used as a coagulant.

• Journal of the Korean Society of Food Culture
• /
• v.27 no.5
• /
• pp.521-527
• /
• 2012

This study was conducted to examine the quality characteristics of tofu prepared with Loquat (Eriobotrya japonica Lindl.) leaf powder (LLP). Moisture, crude ash, carbohydrate, crude protein, and crude lipid contents of Loquat leaf powder were 10.25, 6.72, 69.54, 8.23, and 5.26%, respectively. The yield rates, turbidity, and total acidity of tofu increased according to the quantity of added LLP, whereas pH level decreased. The L- and a-values of samples decreased as the amount of LLP increased, whereas b-value increased. With regard to textural characteristics, LLP addition increased hardness, chewiness, and brittleness, as well as reduced springiness and cohesiveness. In terms of overall acceptability, the most preferred tofu samples were the control and 0.3% LLP addition groups.