• Korean journal of food and cookery science
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• v.20 no.1
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• pp.17-25
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• 2004

This study was carried out to investigate the frequency of use, knowledge, purchasing, and degree of perception of processed soybean by residents in the Kwangwon area of Korea. The frequency of use of soybean curd was once per 4∼6 days(37.9％), once per 2∼3 days(31.9％), once per ten days(25.3％) and everyday(4.9％). The degrees of knowledge about soybean curd were a little(56.0％), interest(16.5％), much(14.8％) and no interest(12.7％). 73.9％ of respondents had no experience of preparation soybean curd. The frequency of places for the intake of soybean curd were home(83.5％), restaurant(8.8％), tofu restaurant(5.6％) and the others(2.1％). The frequency of places for purchasing of soybean curd were supermarket(59.5％), market(25.0％), the others(9.9％) and department store(5.6％). The degrees of perception of soybean curd types were soybean curd(100％), uncurdled soybean curd(93.7％), soft soybean curd(64.7％), bun soybean curd(15.7％) and seaweed soybean curd(5.2％). The experience on the use of processed soybean of the respondents was highest for soybean curd(98.6％), followed by bean sprouts, soybean paste, soy sauce, soybean oil, soy flour, residue of soybean curd, soy milk, in that order. The most frequent intake experiences of soybean processed products of the subjects were beanpaste pot stew(96.8％), followed by tofu pot stew, tofu and kimchi pot stew, uncurdled bean curd pot stew, bean mixed rice, grilled tofu, in that order.

• Journal of the Korean Society of Food Culture
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• v.38 no.5
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• pp.356-364
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• 2023

This study compared the physicochemical properties of soybean curd residue and black soybean curd residue produced by hot air-drying and freeze-drying. Regardless of drying method, the crude protein, crude ash, crude fiber contents, pH, L, a, b color values and water soluble index were higher in soybean curd residue, whereas total polyphenol contents and antioxidant activity were higher in black soybean curd residue. Significant differences in water absorption index, oil absorption capacity and emulsion activity were observed between soybean curd residue and black soybean curd residue in freeze-drying. On the other hand, the emulsion stability was not significant difference in both hot-air drying and freeze-drying. The crude protein and crude fiber contents of soybean curd residue were not significant difference between hot-air drying and freeze-drying. Freeze-drying resulted in higher crude ash contents, pH, water absorption index, water soluble index, oil absorption capacity, emulsion activity and emulsion stability than hot-air drying. Hot-air drying have caused significantly higher water contents, water activity, total polyphenol contents and antioxidant activity in soybean curd residue than freeze-drying. In conclusion, soybean type and drying methods affect the physicochemical and quality characteristics of soybean curd residue, which could be important factors in the manufacture of processed foods.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.583-590
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• 2006

This study was carried out to investigate the acceptable ratio of Sulgidduk with added soybean curd residue powder. The moisture content of Sulgidduk with added soybean curd residue powder (0${\sim}$ 10%) ranged from 40.54 ${\sim}$41.38%, and there were no significant differences between the addition of soybean curd residue powder and control. There were also no significant differences in swelling power and pore ratio from control to the addition of 4% soybean curd residue powder. However, these decreased with increasing addition of soybean curd residue powder of more than 6%. The L (lightness) value decreased with increasing addition of soybean curd residue powder, but the a (redness) and b (yellowness) values increased significantly. As the amount of soybean curd residue powder increased, the hardness, cohesiveness, springiness and gumminess decreased, and, the decrease was especially significant with addition of more than 6%. With increases in the storage period, the hardness, springiness and gumminess increased, while cohesiveness decreased for all additions of soybean curd residue powder. In sensory evaluations, Sulgidduk with the addition of 4% soybean curd residue powder was the most preferred with regard to overall quality. These results indicated that the Sulgidduk with 2% and 4% added soybean curd residue powder exhibited the best quality.

• Journal of the Korean Home Economics Association
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• v.17 no.1
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• pp.12-19
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• 1979

Five kinds of soybean curd were propared with five coagulants, such as, calcium sulfate, calcium chloride, magnesium chloride, glucono delta lactone and acetic acid. The products were evaluated by the sensory and objective examination. Optimal concentrations of each coagulant were determined. Soybean curd preparation was also standardized. The textural characteristics of the five soybean curds which were made by the standard recipe were measured by a Texturometer and a Penetrometer. The results were as follows : 1. From the proliminary study, the optimal concentration of coagulants for the soybean curd preparation, as determined by the sensory evaluation was 1.84% of calcium sulfute, 1.05% of calcium chloride. 1.84% of calcium sulfute, 1.05% of calcium chloride. 1.84% of magnesium chloride, 1.97% of glucono delta lactone and 0.48% 11of acetic acid. 2. As the result of the sensory evaluation, the most acceptable soybean curd was determined to be one with acetic acid. Next, in order of accetability , were magnesium chloride, calcium chloride, glucono delta lactone, calcium sulfate soybean curds and commerical soybean curd. 3. Through the objective examination of the five soybean curds by a Texturometer and a Penetrometer, it was found out that, calcium sulfate soybean curd was the hardest and the hardness decreased in order of glucono delta lactone, magnesium chloride, calcium chloride, and acetic acid soybean curd. Acetic acid soybean curd, the most acceptable , was 0.47 TU ; and calcium sulfate soybean curd, the least acceptable, was 1.73 TU.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.371-375
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• 1997

The content of genistein and daidzein which were known to be major antioxidative compounds in soybeans were detected by $C_{18}$ reverse phase HPLC. Most of isoflavones in soybeans were detected in the methanol extract but much less amount of isoflavones in the water extract. Among the four different kind of soybeans, the isoflavone content was highest in brown soybean, followed by yellow, small black and black soybean, in the order. These isoflavones were known to be soluble in hot water, which means transfer of isoflavone content was highest in brown soybean, followed by yellow, small black and black soybean, in the order. These isoflavones were known to be soluble in hot water, which means transfer of isoflavones in soy curd into whey during soy curd processing. To identify the change of isoflavone content during processing of soybean curd, soybean curd were made from yellow, brown and black soybean and isoflavone content were determined in each soybean curd, curd residue and whey. Most of soflavones were remained in the whey, it means most of useful antioxidative compounds were wasted. Thus, it is necessary to develop new technology to collect these isoflavones lost during soybean curd processing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1431-1435
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• 2007

Soybean curds were prepared by adding different levels (20, 40, and 60%) of small black soybean, and the quality characteristics of the soybean curds were investigated. The yield of soybean curd increased slightly with the increment of the levels of small black soybean, whereas L value (lightness) and b value (yellowness) decreased. Analysis of textural properties demonstrated that the addition of small black soybean lowered the hardness and chewiness of soybean curd, while it slightly increased the cohesiveness and adhesiveness. Antioxidant activities of soybean curd, soybean curd residue, and soybean curd whey were estimated by determining electron donating ability (EDA) to DPPH radical and superoxide dismutase (SOD)-like activity. These activities in all of the samples increased with the addition of small black soybean, especially in soybean curd residue and soybean curd whey; also, soybean curd whey containing small black soybean showed the highest activities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.596-600
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• 2003

This study investigated the effect of soybean-curd residues as an ingredient of the formulated diet for juvenile flounder (Paralichthys olivaceus). Three replicates of juvenile fish (averaging weight $1.5\pm0.04\;g$) were fed one of four isonitrogenous $(50\%)$ diets containing $0\%,\;5\%,\;10\%\;and\;15\%$ soybean-curd residues for 7 weeks. Survival, hepatosomatic index and condition factor of the fish were not affected by dietary soybean-curd residues levels. Weight gain, feed efficiency and protein efficiency ratio of the fish fed the diet containing $5\%$ soybean-curd residues were not significantly different to those of the fish fed the control diet, however these values decreased in the fish fed the $10\%\;and\;15\%$ soybean-curd residues (P<0.05). Daily feed and protein intake increased with increasing dietary soybean-curd residues level. Crude protein and lipid contents in the whole body decreased with increasing dietary soybean-curd residues, but no significant differences were observed among control, $5\%\;and\;10\%$ soybean-curd residues diets (P>0.05). Plasma total protein concentration of fish was affected by dietary soybean-curd residues levels (P<0.05). It is concluded that the soybean-curd residues as a substitute for wheat flour can be included up to $5\%$ in the diet for juvenile flounder.

• Korean journal of food and cookery science
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• v.13 no.1
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• pp.78-85
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• 1997

To determine the optimum coagulants concentrations for preparing soybean-curds, the transmittance of soybean-curd whey using spectrophotometer has been measured. The textural properties of soybean-curds were examined by texture analyzer and sensory evaluations. The general components, oligosaccharides and amino acids in soybean-curd wheys were analyzed. Protein patterns of soybean-curd wheys comparing with soyflour and soymilk were investigated. By texture analyzer, hardness, cohesiveness, springiness, and gumminess of Cacl$_2$ soybean-curd, MgCl$_2$ soybean-curd were higher than those of CaSO$_4$ soybean-curd and GDL soybean-curd. In the sensory evaluations, CaSO$_4$ soybean-curds and GDL soybean-curds were smoother and moister than others. Glutamic acid and aspartic acid were the first two abundant amino acids in three kinds of soybean-curd wheys, but arginine was the most abundant amino acid in GDL soybean-curd whey. Total sugar content of soybean-curd wheys were about 12-13 g/l, and the main sugars among 5 kinds of sugars were sucrose and raffinose. Electrophoresis using SDS-PAGE showed that glycinin and P-conglycinin, the main proteins of soybean appeared in soy flour and soymilk, and only low molecular weight subunits appeared in soybean-curd wheys.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.33-41
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• 1990

This study was conducted to compare the characteristics of the ordinary soybean curd and 3 protein-adding soybean curds (soy protein, casein, gelatin). The sensory evaluation, textural analysis by Instron Universal Testing Machine & the microstructure analysis by SEM for 4 soybean curds were carried out. The results were as follows: 1. In sensory evaluation. 1) The differentiation of soybean curds was greatly explained by `hardness in mouth' through ANOVA test. 2) Discriminant analysis showed that the properties of casein soybean curd were different from those of other three soybean curds by discriminant function I, and the properties of soy protein soybean curd were slightly different from those of ordinary and gelatin soybean curds by discriminant function II. 2. In textural analysis by Instron, protein-adding soybean curds showed significantly lower hardness than ordinary soybean curd. 3. In microstructure analysis by SEM, soy protein soybean curd showed regular, good honeycomb-like network structure and other soybean curds showed lumpy network. The structure of gelatin soybean curd was slightly similar to that of ordinary soybean curd.

• Korean journal of food and cookery science
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• v.29 no.2
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• pp.123-127
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• 2013

In this study the physiochemical characteristics and antioxidant activity of soybean curd were prepared with saltwort (Salicornia herbacea L.). The moisture and protein of the saltwort soybean curd showed no difference among the samples. Ash and lipid were found to be the highest in the soybean curd to which 20% saltwort was added. The contents of mineral(Fe, K, Mg, Zn) were highest in the soybean curd to which 20% saltwort was added, and Ca content was high in the soybean curd to which 16% and 20% saltwort was added. DPPH (1,1-dipheny1-2-picryl-hydrazyl) radical scavenging activity is a method of measuring the antioxidant power of food; this was high in the soybean curd to which 20% saltwort was added. Adding more saltwort led to higher scavenging activity. From the above results, it could be seen that the soybean curd, which is made by adding saltwort, contributed to enhancing the functionality of antioxidant activation and product quality.