• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.973-979
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• 1994

Microorganisms, including the strain IJ-3 isolated from soil, were found to secrete an extracellular soybean protein coagulating enzyme and the strain, IJ-3 was identified as Genus Bacillus according to the Bergey's manual . The enzyme coagulated protein in soymilk , thus forming a curd at pHs 5.8-6.4 and at 55-75℃. The optimum temperature for soybean protein coagulating activity was 65-75℃ and the enzyme was stable at temperature below 50℃ and was found to be stable with about 60-100% of the original activity at a with pH ranges(pH6-7). The molecular weight of enzyme was estimated to be 28,000 by SDS-PAGE. The curd formed with the enzyme from Bacilus sp. IJ-3 has a smooth texture, and a mild taste without any bitterness or a beany flavor.

• Korean journal of food and cookery science
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• v.16 no.2
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• pp.99-111
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• 2000

The purpose of this study was to assess the qualities of cook/chilled soy sauce-glazed soybean curd with various packaging conditions as a trial to develop health-oriented convenience foods. The effects of three packaging methods, linear low density-polyethylene (LLD-PE), top sealing, and modified atmosphere packaging(MAP) on the shelf-life of HACCP-based cook/chilled soy sauce-glazed soybean curd were evaluated during 20 days of chilled storage in terms of time-temperature, microbiological (total aerobic plate count, psychrotrophic plate count, coliform, and fecal coliform count), chemical(pH and peroxide value(POV)), and sensory evaluation. The results of microbiological and chemical analyses were within the limits of the microbial and chemical standards for all phases after cooking. No significant differences were detected in microbial counts of the samples for all three packaging methods. However, sensory evaluation indicated that the top sealing and MAP methods showed a longer shelf-life than LLD-PE packaging. Recommended shelf-life of the product was 12 days for LLD-PE packaging, and 16 days for both top sealing and MAP. In conclusion, MAP was considered as the most effective packaging method for assuring microbial and sensory quality of this cook/chilled product.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.124-129
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• 1986

Soy yogurt beverage (SYB) was preapred from soy protein isolate. The effort of stabilizers or pH adjustment on the sedimentation of SYB curd and the microbiological quality of SYB during storage were investigated. The curd in SYB precipitated significantly during the first 24 hours of storage and the sedimentation of curd could be reduced by the addition of proper amount of CMC or PGA. The sedimentation of curd was also retarded by adjustment of pH of SYB. When SYB prepared by Lactobacillus acidophilus was kept at $5^{\circ}C$ for 48 days, the number of viable cells was not changed and titratable acidity increased gradually. When SYB prepared by L. bulgaricus was kept at $5^{\circ}C$ for 48 days, the number of viable cells decreased slightly and titratable acidity increased gradually.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.267-272
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• 1996

Effect of freezing of soybeans on instrumental and sensory textures of soybean curd was investigated. The hardness, gumminess and chewiness of soybean curd prepared with frozen soybeans were about three times as high as those prepared with unfrozen soybeans, while cohesiveness and elasticity were affected little by freezing. Sensory evaluation showed that freezing improved the quality of soybean curd. Instrumental and sensory textures of soybean curd prepared with frozen soybeans were excellent and almost same regardless of the boiling time when the soy slurry was boiled for 2.5 min or 5 min. However, the textures of soybean curd prepared with unfrozen soybeans were deteriorated by reducing the boiling time to 2.5 min. It was postulated that freezing facilitate the heat-denaturation of soyprotein to enhance aggregation of soy proteins and formation of cross-linkage between aggregate and $Ca^{++}$. Frozen soybeans resulted in soybean curd which lower fat content, while protein content of soybean curd was almost he same. Frozen soybeans gave a lower yield of soybean curd, which is supposed to be caused by the more fat loss during whey-off.

• Food Science and Preservation
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• v.15 no.3
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• pp.361-366
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• 2008

This study was investigated the functional characteristic change by the enzymatic hydrolysate to improve the functionality of soybean milk. The soymilk (SM), hydrolysates of soy milk (HSM), whole soy milk (WSM) and hydrolysates of whole soy milk (HWSM) revealed composition difference whether the bean-curd removal was included or not, but nearly no change was found by the low molecule enzyme treatment. The chromaticity revealed clear difference whether the bean-curd was removed or not, but did not show any difference by the hydrolyzation. Total free sugar and oligosaccharide content was found to be 1,389.88 mg% in SM, 1,013.51 mg% in HSM, 1,539.51 mg% in WSM, and 1,331.53 mg% in HWSM by showing the reduction after the enzyme hydrolyzation. DPPH free radical scavenging activity revealed to show high activity in HSM and in HWSM which were enzymatically hydrolyzed by 49.26% and 45.34%, respectively. And the ACE inhibition activity of HSM and HWSM was found to be approximately 1.6 times higher than the control SM and HSM The superoxide radical scavenging activity revealed to show high activity at HSM and HWSM, and no difference was found by the removal of bean-curd from raw soybean. Based upon these results, the functional characteristics of HSM, WSM and HWSM were found to be excellent compared to SM and it is expected to be used as various functional sources in a future.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.221.1-221.1
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• 2003

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.45-50
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• 1985

Soy yogurt beverage(SYB) was prepared from soy protein concentrate and the effect of stabilizers on the sedimentation of SYB curd and the microbiological quality of SYB during storage were investigated. The curd in SYB precipitated significantly during the first one hour of storage and the sedimentation of curd was reduced by the addition of CMC of over 0.6%, PGA of over 0.2% or Na-alginate of over 0.05%. SYB could be kept for 66 days at $5^{\circ}C$ without significant change in viable cell count of lactic acid bacteria. pH, titratable, acidity and viable cell count of SYB were significantly changed from 42 days of storage at $25^{\circ}C$. Some of SYB samples were contaminated by fungi and the growth of fungi was greatly inhibited by the addition of K-sorbate of 0.005%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.219-225
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• 1982

Four heat conduction models were examined for defatted soy-protein curds in order to get the 'intrinsic' thermal conductivity of soy-protein. As the result of examination, the 'intrinsic', thermal conductivities of soy-protein, frozen and unfrozen states, were determined on the basis of series model to be 0.488 W/m.K and 0.300 W/m.K, respectively. By using the 'intrinsic' thermal conductivity values of soybean protein and the series model, the effective thermal conductivity of soybean curds, with and without fat, at frozen and unfrozen states, was predicted satisfactorily, The temperature dependency of the effective thermal conductivity of soybean curd was mostly observed to correlate with the thermal conductivity of water and ice.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.828-832
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• 2004

Enzyme-linked immune sorbent assay (ELISA) was applied to quantify soy protein in fresh soybean curd (bean curd) produced by combination of genetically modified (GM) and genetically not modified (non-GM) soybeans. Antibodies against 113 and 24 kDa proteins, which appeared only in non-GM bean curd (specific band), and in both non-GM and GM bean curds (non-specific band) based on SDS-PAGE results, were prepared by immunization to rabbit. Through ELISA using either antibody, GM bean curd protein content was determined at dilution rates of $10^{-1}-10^{-6}$. Standard curve showing relationship between ELISA optical density and non-GM protein content was produced using antibody against 113 kDa protein at protein dilution between $10^{-7}\;to\;10^{-6}$, highly antigen content-dependent dilution. Bean curd prepared by random combinations of GM and non-GM soybeans were analyzed by ELISA, and standard curve was produced. Results reveal non-GM protein content of bean curd could be quantified with higher than 93% accuracy.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.2
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• pp.107-122
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• 2002

The purpose of this study was to develop menus for daily intake of 25g soybean protein and to analyse nutrients of these foods. Analytical values were compared to the theoretical one using the flood composition table and recommended dietary allowances for Koreans (7th revision). The results are as follows. 1. Soybean curd residue stew, Soybean curd, Kimchi saute, and hard boiled soybean and lotus root were selected for the menu for January, of which the content of soy bean protein(SBP) was 33.1g, soybean stew, soybean curd and soybean sprout saute, and Italian deep fried soybean curd were fur February, of which the content of SBP was 35.0g. The content of SBP in soybean paste soup with soybean curd, fried soybean curd and fried soybean curd roll, the menu for March, was 24.9g. That of April were soybean curd gratin with soymilk, soybean curd and ham with garlic dressing and the content of SBP was 26.3g. That of May were soybean porridge, soybean flour cake with honey (Dasik), soybean sprout soup and the content of SBP was 26.7g. That of June were soymilk, pan-fried soybean curd, steamed soybean curd with chicken and the content of SBP was 28.4g. That of July were noodle with soymilk, mapatofu, soybean curd salad and the content of SBP was 24.7g. That of August were soybean sprout with mustard dressing, Tossed green pepper with raw soybean flour, Tofu and Kimchi stew, soybean curd steak and the content of SBP was 26.2g. That of September were Chinese cabbage soup with raw soybean flour, sweet and sour tofu and the content of SBP was 23.2g. That of Oct. were Fermented soybean stew, soybean pan cake and the content of SBP was 24.3g. That of November were not-pressed soybean curd casserole, pan-fried mashed soybean curd with egg, stir frying deep-fried soybean curd with vegetables and the content of SBP was 22.4g. That of December were soybean curd and mushroom casserole, fried soybean curd and vegetables, hard boiled soybean curd and the content of SBP was 28.9g. 2. The ratio of the analytical value over theoretical value (A/B%) of one serving in kcal, carbohydrate, protein, fat ash and dietary fiber were 57.7~107.7% 42.9~131.9%, 79.2~118.3%, 54.5~ 100%, 40.7~80.8% and 42.1~113.2%, respectively.