• Food Science and Preservation
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• v.20 no.5
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• pp.636-642
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• 2013

Quality and sensory characteristics of tofu prepared with concentrated to 8 $^{\circ}Brix$ deep ground sea-like water (SW) were investigated to check the availability for coagulants. The tofu was coagulated with three kinds of commercially coagulant, such as $MgCl_2$, $CaSO_4$ and glucono-${\delta}$-lactone. Different amounts of SW and soybean milk were added: SW-20 g/L, SW-25 g/L and SW-30 g/L. The moisture content and pH were significantly lower in which preparation with glucono-${\delta}$-lactone coagulated tofu, and others has not significantly difference each other. The mineral contents in the coagulant influenced the mineral content of the tofu, which contained larger quantities of major minerals. However, the mineral content of the tofu was not affected of the mineral concentration in the coagulant. The L and b values of the tofu prepared with SW were not significantly different. The hardness of the tofu prepared with the commercial coagulants was significantly lower than that of the tofu produced with the SW. The sensory property was lower when the hardness was lower and higher. In conclusion, the quality characteristics of SW-prepared tofu were not significantly different from those of the tofu prepared with the commercial coagulants, but the texture and the taste of the SW-prepared tofu were excellent.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.370-378
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• 1994

Soybean curd added with 40% of cow’s milk was prepared with eight coagulants such as calcium acetate, calcium lactate, calcium chloride, calcium sulfate, magnesium chloride, glucono-delta lactone (GDL), acetic acid and lactic acid. The curd products were evaluated by the chemical composition, coprecipitation porperties, mineral content, yield, color and textural characteristics. The lowest concentrations for protein coprepitation were 0.3% (v/v) for calcium salts, 0.4% (v/v) for magnesium chloride, 0.2% (v/v) for organic acids. Turbidity and crude protein of whey were markedly decreased at these concentrations. The optimal concentrations of coagualnts used for soybean curd preperation were 1.2% (v/v) for calcium acetate, calcium sulfate and calcium lactate, 1.0% (v/v) for calcium chloride and GDL, 0.8% (v/v) for magnesium chloride and lactic acid, 0.6% (v/v) for acetic acid. It was observed that of the eight coagulants tested, calcium chloride provided a satisfactory curd in quality. Calcium content of soybean curds by the calcium salt coagulants was higher than that by organic acid coagulants. Through the examination on the textural properties by a texturemeter was found out that acetic acid treated soybean curd among the organic acids, calcium salts and magnesium chloride treated curds had very high hardness value. All the curd products prepared in this experiment had a pale yellow color as affected by the value of L (lightness), a (redness) and b (yellowness). Although the colorimetric readings showed that the soybean curds prepared with the organic acids had higher L value but lower a and b value in comparison to calcium salts and magnesium chloride treated curds.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.402-409
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• 2000

To investigate the textural and physical characteristics of WSF(whole soybean flour) tofu affected by coagulant and its concentration, $CaCl_2$, $CaSO_4$, $GDL(glucono-{\delta}\;lactone)$, $MgCl_2$, and some mixed coagulants were used in this study. Yields of WSF tofu coagulated with $CaSO_4$ and GDL were ranged 4.3-4.5(g/g WSF), but common tofu was 2.2-3.0(g/g soybean). As the water addition ratio increased, L and a value were increased while heating time increased, b value increased. L value of WSF tofu was lower and b value was higher than conventional tofu and 4 commercial tofus. Kinds of coagulant and its concentration significantly affected to textural properties of WSF tofu. As the concentration of coagulant increase, the hardness increased in most all coagulants. WSF tofu coagulated with $CaSO_4$ and GDL recorded low hardness and adhesiveness, and high springiness among the used coagulants at the same concentration. As the hardness increased, the gumminess and chewiness increased in most all coagulants. As coagulation temperature and molding pressure increase, hardness also increased. WSF tofu coagulated with 0.3% $CaSO_4+GDL$ was the most similar in the textural properties with conventional tofu and 4 commercial tofus. WSF tofu coagulated with 0.3% of $CaSO_4+GDL$ at $85^{\circ}C$, 10 times water addition, 5min. heating and $25.0g/cm^2$ molding pressure recorded the highest score in the sensory evaluation.

• Food Science and Preservation
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• v.21 no.5
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• pp.688-693
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• 2014

The quality and sensory characteristics of tofu were investigated with various levels of black garlic extract (BE) added to it in 0, 1, 3, 5 and 7%-weight soymilk, before it was coagulated with $MgCl_2$ (MC, BEM-A, BEM-B, BEM-C and BEM-D) and concentrated to $8^{\circ}Brix$ deep ground sea-like water (SC, BES-A, BES-B, BES-C and BES-D). The overall acceptability of the tofu samples was higher (SC > BES-A > BEM-A) than that of the other samples. The addition of BE was influenced by the color, flavor and taste of the tofu, and the more BE was added, the tougher the tofu became. The tofu yield with various amounts of black garlic extract did not significantly differ among the samples. The pH range was 5.61~6.15 and decreased as more BE was added, whereas the turbidity increased. Also, the L value of the tofu decreased as more BE was added. The a value showed a tendency opposite that of the L value. The b value did not significantly differ among the samples. The texture profile analysis of the tofus showed that the hardness, chewiness, and gumminess significantly increased as more BE was added. In conclusion, it was found that the addition of 1% BE will improve the quality and sensory characteristics of tofu.

• Applied Biological Chemistry
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• v.46 no.3
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• pp.183-188
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• 2003

Storage stabilities of soybean curds using cuttle bone powder treated with acetic acid (ATC-soybean curd) and calcium chloride (calcium chloride-soybean curd) as a coagulants were examined. The pH, turbidity of soaking solution, titratable acidity, and viable cell counts of calcium chloride-soybean curd did not change up to 6 days of storage, then decreased rapidly in pH and turbidity and increased rapidly in titratable acidity and viable cell counts, whereas those of ATC-soybean curd did not change up to 9 days of storage, then decreased slowly in pH and turbidity and increased slowly in titratable acidity and viable cell counts. Regardless of coagulants and storage period, white index of soybean curds did not change during cold storage. Hardness and brittleness of calcium chloride-soybean curd decreased rapidly up to 3 days in of storage, remained stable from 3 days to 6 days, then decreased rapidly. Hardness and brittleness of ATC-soybean curd also decreased rapidly up to 3 days in of storage and remained stable from 3 to 9 days, but then decreased slowly. Regardless of coagulants, results of sensory evaluation were similar to those of physicochemical tests. Judging from the above results, shelf-lives were determined as 9 and 6 days for ATC- and calcium chloride-soybean curds, respectively.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.699-705
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• 2014

This study was conducted to select the coagulant for konjac processing and to identify the antibacterial activity on foodborn pathogens by concentration of $Ca(OH)_2$. In rheological properties such as hardness, gumminess and chewiness, konjac jelly were increased by progressing coagulation regardless of coagulant. In mineral contents, the Ca content of konjac jelly made with $Ca(OH)_2$ was significantly higher than that of NaOH. On the contrary, the Na content of konjac jelly made with NaOH coagulant was significantly higher than that of $Ca(OH)_2$. There were no significant differences in the Mg and P contents according to coagulant. In sensory evaluation, there were no significant differences in the color, flavor, taste, texture and overall quality according to coagulant. The antimicrobial activities of Staphylococcus aureus, E. coli, Salmonella typhimurium were inhibited in proportion to the concentration of $Ca(OH)_2$. According to the manufacturing process of konjac jelly, the change in microorganism was not found after molding.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.34-35
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• 1994

Tube-in-orifice형태의 spinneret을 제작하여, polyethersulfone을 재질로 하는 capillary membrane을 건습식방사공정을 통해 제조하였다. 기공형성계는 PVP를, 용매는 NMP/DCM을, 내부응고제는 물과 NMP의 혼합물을, 외부응고제는 냉각수를 사용하였다. 내부응고제의 NMP농도에 따른 막의 형태와 microstructure를 연구하였다. 내부응고제가 약한 응고력을 가질 때 macrovoid가 없고, 내부의 활성층이 치밀한 막을 얻을 수 있었다. PES-NMP/DCM-PVP조성(25-44/11-20)의 용액으로, 40% NMP수용액을 내부응고제로 사용하여, 막을 제조하고 이를 모듈화하여, 한외여과실험을 한 결과, MWCO 8,000인 모듈이 얻어졌으며, 이 모듈의 Flux는 1기압에서 $1.44 \times 10^{-5}m/sec$이었다.

• 베이커리
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• no.7 s.432
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• pp.165-167
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• 2004

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.26-30
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• 1994

The purpose of this study was to investigate the effects of heating times of soy protein isolate(SPI) and mixing ratio of coagulants mixture on water holding capacity(WHC) and oil absorption capacity (OAC) of SPI, texture properties and yield of tofu. The effect of heating at $100^{\circ}C$ on the amounts of coagulants required for coagulation showed that the amounts of $CaCl_{2},\;MgCl_{2}$ and GDL decreased as the heating time extended to $6{\sim}9$ minutes while $CaSO_{2}$ was changed little. The tofu yield showed maximum for the tofu prepared by 6 minutes boiling and coagulation with $CaSO_{4}$. The WHC of SPI was significantly reduced by heating at $100^{\circ}C$ while OAC was rather increased until 9 minutes of heating. The textural properties of SPI tofu coagulated with mixed coagulants$(CaSO_{4}-GDL,\;CaSO_{4}-CaCl_{2},\;CaCl_2-GDL)$ showed that softer tofu was obtained as the ratio of $CaSO_{2}$ increased and harder tofu as the ratio of $CaCl_{2}$ and GDL increased. The maximum and minimum tofu yields were prepared from 100% of $CaSO_{2}$ and 100% of GDL, respectively. Organoleptic properties showed that more uniform and tender tofu were obtained with higher portion of $CaSO_{2}$ in the mixed coagulants and higher intensity of sourness and bitterness were scored as the GDL and $CaCl_{2}$ added more.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.286-292
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• 2009

This is the basic study of Cheong-song mineral waters(Dalgi and Sinchon) for a coagulant of Tofu. For comparison, $CaCl_2,\;CaSO_4,\;MgCl_2\;and\;MgSO_4$ are used as reference coagulants. The coagulability test was conducted by measuring the percentage transmittancy of filtered whey solution at 600 nm wavelength, in $80\;{^{\circ}C}$ and 10 mL of solution volume which composed of 2 mL of soy milk and coagulants. The coagulability test of mineral waters require more than an aliquot of 8 mL. Good result obtained by adding 0.4, 1, 0.8, 0.8 mL of reference coagulants and this is equivalent to the amount of 66.14, 232.83, 95.68, 78.88 mg of Ca and Mg respectively. The percentage transmittancy of filtered whey solution with added 8 mL of Dalgi and Sinchon mineral waters showed 50.74 and 58.52 respectively and the amount of mineral content of Ca and Mg equivalent to 2.41 and 2.48 mg respectively which is very lower value than the reference coagulants. This means mineral water has coagulation ability even in the low concentration.