• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.4
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• pp.381-386
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• 1985

This experiment was conducted to investigate changes of soybean curd yield according to the extension of soaking time during manufacturing of soybean curd. To investigate those changes systematically, transmission electron microscopy and disc-gel electrophoresis were used. The soybean curd yield was increased from 45.0% to 50.5% and 55.4% respectively as soaking time is extended from 5 hours to 10 and 24 hours. The solid extraction and soybean milk coagulation were also increased according to the extension of soaking time. From disc-gel electrophoresis patterns of soybean milk protein and soybean curd protein, numbers of band were increased and major band thickened by expending the soaking time. Most of high molecular bands of soybean milk protein were transfered to soybean curd. Crude 7S proteins of soybean milk and soybean curd in dis-gel electrophoresis were appeared to be 4 and 5 bands respectively, and crude 11S proteins of soybean milk and soybean curd were appeared to be 9 and 8 bands respectively. Of soybean milk bands, most of 11S component transfered to soybean curd. Transmission electron photomicrographs revealed that the dimension of each protein body became larger and the numbers of spherosome around the protein bodies in unit area fewer by extending the soaking time of soybean.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.837-844
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• 1994

In order to making the good quality soybean cheese, it is prepared byover growing cow's milk added soybean curd with Actinomucor elegans and the nold-overgrown curd soked in salt-brine/ethanol mixture. The physicochemical changes and sensory evaluation were investigated during the aging period. Crude protein, carbohydrate, crude fat ash contents of the pehtze were increased by elapsing the fermentation time, whereas moisture's decreased . Amino-N and ammonia -N contents of cow's milk added pehtze and soybean phetze were increased 17.25%, 7.23% and 16.16%, 8.42% respectively. Total nitrogen content of the pehtze was decreased by elaping the aging time but soaking solution's increased. Free amino acid content of soybean cheese was increased as a result of the proteolytic action of molds. As a result, sulfur containing amino acid such as methionine and cysteine of the cow's milk added soybean cheese were enriched 1.3 times more than the soybean cheese. Flavor, taste and texture of the cow's milk added soybean cheese were higher than soybean cheese.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.259-262
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• 1997

The microstructures of soybean milk curds, prepared by different coagulation methods, were observed by the scaning electron microscope. Th curd coagulated by theaddition of bacerial soybean mil clotting enzyme showed little textural changes and gave smoother gel than those prepared either by lactic acid fermentation using Streptococcus thermophilus or by the addition of CaSO$_4$. The curds obtained by lactic acid fermentation and by the addition of inorganic salt exhibited three dimensional network structure which indicated harder gel than that prepared by soybean mil clotting enzyme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.137-141
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• 1979

A study on the processing of soy curd powder with soybean milk and kril autolasate has been carried out to prolong tile self life and to improve the taste and colour of soy curd. The soy curd was manufactured by coagulation of the soybean milk prepared from soybean through a series of processes of soaking, grinding, heating at $500^{\circ}C$ for 5 minutes and filtration. Ten hours was reasonable as the soaking time of the soybean for the high yield of soybean milk. The use of $3\%$ $glucono-\delta-lactone$ to the weight of the raw soybean showed the best coagulation of the soybean milk at $90^{\circ}C$ in relation to the yield and content of crude protein of the soy curd. The soy curd powder prepared by spray drying of soyben milk could be coagulated at $90^{\circ}C$ by the addition of $glucono-\delta-lactone$ after suspending in water. The powder manufactured by spray drying of the mixture of soybean milk and drill autolasate could also be coagulated under the same conditions to produce the soft soy curd. Another powder prepared by spray drying of the mixture of soybean milk, krill autolysate and $glucono-\delta-lactone$ could be coagulated by standing at room temperature after 2 minutes boiling.

• 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.24 no.3
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• pp.294-299
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• 1992

This study was to examine the effect of functional properties of soy protein isolate(SPI) and qualities of soybean curd upon proteolytic hydrolysis. SPI was hydrolyzed using proteolytic enzyme, bromelain. The protein content of SPI by microkjeldahl method was 84% and the degree of hydrolysis in modified soy protein isolate(MSPI) was 2.7%. The solubility of MSPI was higher than that of control at various pH tested and proteolytic hydrolysis was increased emulsion formation and foam expansion while decreased emulsion stability, foam stability and calcium precipitation. Modified soybean curdI, standard soybean milk: Modified soybean milk=3:1, was soft and springy soybean curd when the texture properties of soybean curd were tested by texture profile analysis using Instron and sensory evaluation. The rheological model of soybean curds was investigated by stress relaxation test. The analysis of relaxation curve revealed that the rheological behavior of soybean curds could be expressed by 7-element generalized Maxwell model. The equilibrium modulus and modulus of elasticity decreased as the ratio of modified soybean milk was increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.401-406
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• 1983

Changes in the soluble sugar content contained in the soybean, soybean milk, soybean curd and soybean whey were determined to investigate the method of reducing the introductions of soluble oligosaccharides like sucrose, raffinose and stachyose, which cause flatulence in human, to soybean curd from soybean by extending the soaking time of soybean. The soybean curd yields according to the extention of the soaking time were also determined. Markedly increased glucose, slightly reduced fructose and sucrose and noticeably reduced raffinose in soybean milk were observed with extended soaking time. Most of sucrose, raffinose and all of maltose were transferred to soybean whey. Gradual increase of soybean curd yields were obtained by extending soaking time within the experimental conditions.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.275-282
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• 2008

In this study, the soy food intake behaviors including perception and intake frequency of soybean foods by sociodemographic variables were analyzed in housewives. The perception of housewives for soy foods showed that soybean paste, soybean curd, and Dambuk were high in the descending order for nutritional quality and health promotion effect, and soybean paste received the highest score in taste and flavor. Soybean sprouts received the highest evaluation score in the economic aspect. In the aspect of safe food, soybean paste received the highest evaluation score, as mush as a traditional food. The analysis of perception by sociodemographic variables showed that soybean curd, Dambuk, and soybean sprouts had higher perceptions as education level increased, and soy milk had higher perceptions in subjects with younger age and with employment. In the intake frequency, more than 50% of the subjects had soybean curd, soybean sprouts, and soybean paste more than once a week. The analysis for correlation between the intake frequency of soy foods and the degree of perception showed that taste and flavor had high correlation with the intake frequency of soy foods except soybean sprouts. The intake frequency of soybean paste, Dambuk, and soy milk had positive correlations to familiarity and that of soy milk had positive correlations to nutrition and health perception, and those of soybeam paste, soybean sprouts, and soy milk had positive correlations to safe food perception. From the above results, housewives in Korea had very high perceptions to nutritional quality and health promotion effect of soy foods and the degree of perception and accompanied intake frequency had significant differences by age, education level, and economic level among sociodemographic variables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.437-442
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• 1993

Soybean curds were made from the mixture of soybean milk and cow's milk (raw milk) at the ratio of 10, 20, 30, 40, 50% (v/v), and then the general composition and mineral content, pH, yield, firmness by sensory evaluation and amino acid composition were investigated. As cow's milk addition increased, total sugar crude fat, crude protein, ash content, firmness, weight and volume of the soybean curd were increased. Whereas moisture content decreased, $Ca^{＋＋}$, $K^{＋}$, and Na$^{＋}$ were increased, but $Mg^{＋＋}$ and Fe$^{＋＋}$ decreased. In sensory evaluation, color (white), firmness, flavor, and taste were higher than those of control as cow's milk increased. By adding cow's milk at the ratio of 10, 20, 30, 40%, and 50%, sulfur containing amino acid content such as methionine and cystine were enriched 1.31, 1.58, 1.67, 1.85, and 1.95 times, respectively.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.355-358
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• 1994

The effect of concentration of coagulant and addition of phytic acid on physico-chemical properties of soybean curd was investigated. The results showed that the maximum protein yield in soybean curds was obtained with 0.029N Ca and the bound calcium per protein molecule significantly increased as the level of calcium increased. The highest precipitation of phytic acid occured at 0.029N Ca. When phytic acid was added to soybean milk during soybean curd preparation, the weight of soybean curd increased. The hardness of soybean curd was remarkably reduced by the increase of phytic acid level.