• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1096-1101
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• 1997

Soy curd was prepared using imported soybean(U.S.grade A) and changes in quality were evaluated using different types and mixtures of coagulants(CaCl$_2$, CaSO$_4$, MgCl$_2$, MgSO$_4$, and glucono-$\delta$-lactone). Quality of soy curd was determined by rheological properties, yield, and color. Based upon the characteristics of each coagulant, mixtures of two coagulants were prepared in various ratios. The mixture of CaSO$_4$or MgCl$_2$with glucono-$\delta$-lactone(GDL), and that of CaSO$_4$or MgCl$_2$with MgSO$_4$resulted in soy curd of good quality in terms of rheological properties and yield.

• 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.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.700-706
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• 1990

The curd yogurt was prepared from milk or milk added with skim milk powder or soy proteins. Acid production by lactic acid bacteria in milk containing additive of 2% was investigated and quality of curd yogurt(sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. The soy proteins, particularly defatted soy flour or soy flour, stimulated acid production by lactic acid bacteria more than skim milk powder. Among the four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid and acetic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. The major organic acid produced during the fermentation was lactic acid. Addition of soy proteins to milk reduced sensory property of curd yogurt. Among the soy proteins tested, soy protein concentrate or soy protein isolate added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, titratable acidity, pH and number of viable cells of curd yogurt were not changed.

• Food Engineering Progress
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• v.21 no.3
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• pp.242-248
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• 2017

The acidity of soy curd fermented by lactic acid bacteria is a major factor degrading the sensory properties of soy curd. For preparation of soy curd with low sour taste, lactic acid bacteria were separated from kimchi. The lactic acid bacteria which showed yellow-clear zone around the colonies on BCP plate and formed soy curd with low level of acidity were selected. The selected strain was analyzed by 16S rDNA sequence and named as Pediococcus inopinatus Y2. The maximum viable cell number of the soy curd fermented by P. inopinatus Y2 was obtained at 10.73 log CFU/mL at $25^{\circ}C$ for 24 h of fermentation. By the results of panel test, the overall sensory quality of the soy curd produced by P. inopinatus Y2 was higher than that of Leuconostoc mesenteroides No. 4395 and Lactobacillus sakei strain No. 383.

• 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 Science and Technology
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• v.26 no.5
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• pp.603-608
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• 1994

This study was undertaken to find out the effect of phytate on the protein digestibility of various soybean foods, including soy milk, bean curd, curd residue, cheongkukjang, soy sauce, and soy paste. The phytate content of soybean was 2.4%, which decreased to 0.2%, 0.7%, and 0.4% in soy milk, bean curd, and curd residue, respectively, and to 0.2% and 1.0% in soy sauce and soy paste, respectively. The phytate/protein ratio was not correlated with protein digestibility by pepsin whereas the ratio was highly correlated with pancreatin digestibility (p<0.01, r= -0.73). According to SDS-PAGE for the soluble protein fractions, soaked bean showed an alteration in soluble components and bean curd residue exihibited newer low molecular weight bands. Fermented soy products showed no protein band, likely due to degradation.

• Journal of Life Science
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• v.21 no.2
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• pp.235-241
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• 2011

The purpose of this study was to isolate soy curd forming bacterial strains. Soy curd forming bacteria were isolated from Kimchi, a traditional Korean vegetable food that is fermented using lactic acid bacteria. Among 196 bacterial strains, ten isolates (strain No. 2-2-2, 2-15-2, 2-18-1, 2-19-2, 3-4-1, 3-4-2, 3-8-1, 3-8-3, 3-17-1, 4-39-5) formed firm soy curd. The isolated bacterial strains were identified by molecular biological and biochemical analyses. The genomic DNAs extracted from the isolated bacterial strains were used as a template for PCR amplification of 16S rDNA region. By comparing the results of the 16s rDNA sequences with GenBank data, the isolated strains were identified as Leuconostoc mesenteroides group and Lactobacillus sakei group. The phylogenetic position of soy curd forming strains and their related taxa were investigated using neighbor-joining method. L. mesenteroides group was further identified as L. mesenteroides subsp. dextranicum based on biochemical properties. L. sakei group was named Lactobacillus sp., because it showed a variety of biochemical properties.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.53-58
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• 1996

The characterstics of the soy protein curd(eczyme-, HCI- and Ca-surd) were shown by scanning electron micrographs and gel electrophoreis. The emulsion stability of enzyme-curd showed high value in the range of pH 2~10and wide range of temperature(20~8$0^{\circ}C$). While at the isoelectric point(pH5.0), the emulsion stability of the HCI-and Ca-curd was decreased remarkably, and the emulsion stability of temperature was reduced quickly to the 60% and 40% at the 4$0^{\circ}C$. The foam stability of enzyme-curd was slightly higher than that HCI-and CA-curd in all ranges of pH and temperature. The feature of SEM of enzyme-cured produced degradation products faster than that of the HCI- and Ca-curd.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.2
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• pp.45-49
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• 1994

The rapid preparaton method of soybean curd with ultra fine soy powder at home was investigated. The microwave oven of this study used common microwave attached sensor for the volume and temperature control, The temperature of the microwave oven was maintained at 98, not boiling over. It took 9 minutes to make 300g of soybean curd, 10 minutes to make 600g, 14 minutes to make 900g, and 17 minutes to make 1200g. Beany flavor and trypsin inhibitor could be removed by this conditon. It took only 5 min to make coaguation of the curd by glucono-$\delta$-lactone.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.1-7
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• 1985

This study was conducted to investigate the effect of fat on gain percent, yield and sensory properties of soybean curd by partial or whole replacement of soybean with defatted soy flour, The results obtained were as follows ; 1. Gain percent and yield of soybean curds were decreased as the fat content of materials decreased. 2. In sensory evaluation, the mean scores for appearance (color and smoothness), texture and acceptability significantly decreased as the ratio of defatted soy flour to soybean increased. However, when the defatted soy flour replaced 20 and 30％ of the soybean, the mean acceptability scores did not differ significantly with whole soybean curd. From the above data, if defatted soy flour will be used for making soybean curds with the aspect of sensory and economic reasons, 25％ level of replacement can be recommended.