• Korean journal of food and cookery science
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• v.24 no.2
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• pp.258-265
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• 2008

This study investigated the quality characteristics of tofu(soybean curd) samples prepared with differing amounts of commercial chungkukjang powder(0, 1, 2, 3, 4%). According to the results the 3% chungkukjang tofu 3%(C3) had the highest yield, and the tofus containing chungkukjang powder had higher pH and acidity levels than the control. Turbidity increased and moisture content decreased with increasing chungkukjang powder concentration. And pH, acidity, and turbidity were negatively correlated with moisture content. In terms of color, the L value decreased, and a and b values increased with increasing chungkukjang concentration. For texture, the 1% chungkukjang tofu(C1) had higher hardness, springiness, and cohesiveness values than the other samples. C1 also had the highest overall acceptability score. Finally, sensory properties of taste, texture, and overall quality were positively correlated with the mechanical properties of moisture content, hardness, springiness, cohesiveness, chewiness, and brittleness.

• 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.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.71-75
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• 2009

The effects of Rhynchosia volubilis (yakong) incorporation (0%, 10%, 20%, and 30%, w/w of soybeans) on quality and shelf life of tofu were investigated. Moisture content of tofu increased slightly with the increase in the level of yakong incorporation from 10% to 30% and no apparent relationships between yakong incorporation and the yield were found. Turbidity of soybean whey tended to increase with increased level of yakong incorporation where the values of 20% and 30% samples were significantly different from those of control and 10% sample (p<0.05). The different levels of yakong incorporation were found to have significant influence (p<0.05) on all the color characteristics of tofu. Tofu texture varied with the level of yakong incorporation in consistent pattern; however, there was no significant difference (p>0.05) in most cases. Tofu incorporated with yakong ($10{\sim}30%$) had a shelf life of above at least 1 day longer than that of the control tofu.

• 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.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.825-831
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• 2006

This study investigated the utilization of apricot as a coagulants for tofu manufacture, and compared the quality characteristics and shelf-life of tofu made by A2(2% apricot juice), A4(4% apricot juice), A6(6% apricot juice), A8(8% apricot juice) in comparison with those of C(G.DL). A2 tofu(323.00 g) showed the highest yield of tofu and the tofu yield decreased with increasing apricot juice content. In color, the lightness of tofu was decreased with increasing apricot juice content, while redness and yellowness were increased. The hardness of tofu coagulated with apricot juice was higher than that of the coagulated C(G.DL) and the springiness of A6 and A8 was higher than that of C(G.DL) while that of the other tofus was lower than C(G.DL). The brittleness of tofu was increased with increasing apricot juice content. The pH value of tofu coagulated with apricot juice was increased during storage at $0^{\circ}C$ and the acidity was decreased. Two percent apricot juice tofu had good overall preference.

• Journal of the Korean Society of Food Culture
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• v.22 no.6
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• pp.713-720
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• 2007

To investigate of the recognition and using behavior on the Tofu, 46.3% of male and 53.7% of female adults in Daegu and Kyungbuk area were surveyed. The main results are as follows : 96.4% of the participants usually preferred the Tofu owing to health and about 68.4% of them had purchased Tofu made of domestic soybean. In addition, the responses to 7 questions about the Tofu were also measured on 5 point Likert scale. The item "Tofu is healthy food" and "Tofu is digestive food" were totally received the high point but "Tofu prevents osteoporosis" earned the lowest. Female had generally better knowledge of Tofu than the counterparts. Most participants relatively knew and had eaten common Tofu, soft bean curd, uncurdled bean curd, fried bean curd against functional Tofu such as Tofu added with omija, surimi, spinach, etc. But they intended to eat functional Tofu such as Tofu added with green tea, black sesame, spinach, omija. Furthermore, 60.7% replied "increasing" prospects for the Tofu consumption. 40.0% of adults said the plan should be "Make of good quality domestic soybean" for the purpose of better improvement to consume.

• Food Quality and Culture
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• v.2 no.1
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• pp.27-31
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• 2008

The objective of this study was to develop sensory lexicons that can be utilized for various types of tofu such as pressed, unpressed, and tofu made from germinated soybeans, using generic descriptive analysis. In the first phase of the experiment, trained descriptive panelists developed and defined the appearance, aroma, flavor, and texture attributes that are commonly present in tofu. Then, the sensory characteristics of seven types of tofu were analyzed using the sensory lexicons established in the initial stage of the experiment. Four appearance, 6 odor/aroma, 6 flavor/taste, 7 texture, and 4 aftertaste attributes were identified, and reference standards were established for most of the terms in order to facilitate the understanding of the attribute definitions. The intensities of the sensory attributes were measured on a 15-point scale. Statistical analyses, including analysis of variance and principal component analysis, were used for the data. The seven tofu samples showed significant differences in the intensities of 22 attributes. The unpressed tofu samples were generally rated as being high in moistness, easy to cut, silky, and easy to swallow. The pressed tofu, on the other hand, was salty, astringent, beany, hard, and rough in texture. The tofu made with germinated soybeans was characterized as having a strong cooked bean flavor, salty and astringent aftertaste, and hard texture. Overall, the attributes of moistness, easy to swallow, and silkiness showed strong positive correlations; hardness and sticks to teeth were also positively correlated to each other.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.707-716
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• 2006

To make tofu (soybean curd) with cuttlefish int the cuttlefish ink diluted 20-fold was added to soymilk in the ratio of 0%, 1%, 3%, 5%, 7% and 9% there is no respective comparison here respectively and the prepared cuttlefish inky tofu samples were stored for 15 days at $4^{\circ}C$. After storage, the tofu samples were tested for yield, pH, acidity, bacterial growth, sensory evaluations and physical properties. The yields of 7%(I7) and especially 9%(I9) cuttlefish ink tofu were higher than that of the control tofu(I0). The pH was decreased, but the acidity was increased with increasing storage period. The microorganism count of I9 was the lowest during the storage period. The turbidity gradually increased until 9 days of storage and rapidly increased at 12 days of storage. In the measurement of inky tofu color, the L and b values were decreased during the storage period. In the texture analysis, the hardness, gumminess and brittleness of inky tofu were increased until 12 days of storage but then decreased. Chewiness was decreased with increasing storage period. Springiness of Il and I3 was higher than that of I0. In sensory evaluation, color was increased with increasing cuttlefish inky concentration. Sleekness of I3 was the highest. Hardness and chewiness of inky Il and I3 were the highest. Springiness, cohesiveness and softness were the highest in I3. In overall acceptability, I3 gained the highest score.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.62-69
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• 2018

Pumpkin (Cucurbita moschata Duch.) seed is rich in protein and sulfur-containing amino acids. Tofu is a protein gel made from soybean, which is rich in lysine but lacking in sulfur-containing amino acids. This study was conducted to investigate the use of pumpkin seeds in tofu manufacture and to determine its quality and texture characteristics. Soybean was substituted with pumpkin seed to obtain pumpkin seed tofu at the following ratios: 10%, 30%, 50%, and 70% (P10, P30, P50 and P70). Tofu manufactured only with soybean was used as a control (Con). The higher rate of pumpkin seed substitution significantly decreased the moisture content and yield rate (p<0.05). In contrast, pH value and turbidity were significantly increased with the increase in the amount of pumpkin seed (p<0.05). The L-value (81.74~79.04), a-value (-0.19~-3.89) and b-value (12.40~9.84) of samples significantly decreased with the amount of pumpkin seed (p<0.05). No significant difference in syneresis was found among the samples (p<0.05). The hardness tended to decrease with the increase in the amount of pumpkin seed. The microstructure analysis revealed that the pore size of pumpkin seed tofu was smaller than that of Con. These results suggest that the pumpkin seed protein is a useful ingredient in the manufacture of tofu. Increasing the pumpkin seed substitution levels improves the texture of 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.