• Applied Biological Chemistry
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• v.37 no.4
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• pp.259-265
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• 1994

To investigate the effects of protein concentration, heat treatment and pH on the foaming properties of sodium caseinate, surface tension, apparent viscosity, turbidity, foaming ability and foam stability at 1.0, 3.0, 5.0, 7.0 and 10.0% (W/V), at 55 and $65^{\circ}C$ and at pH 6.0, 7.0 and 8.0 were examined. The conditions of protein concentrations for the foaming abilities were $3.0{\sim}7.0%$ (W/V). Foam stabilities of heated sodium caseinates were worse than those of unheated sodium caseinates (control) at pH6.0 and 7.0 (p<0.05), while the heated one were better than the unheated at pH 8.0, 10.0% concentrations (p<0.05). Also foam stabilities of sodium caseinate at pH 6.0 were higher than those at pH 7.0 and 8.0. Foaming ability and foam stability were inconsistently effected by changing protein concentration, heat treatment and pH.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.836-842
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• 2007

In this study, we investigated the effects of heating ($80^{\circ}C$, 30 min) on the physicochemical and functional attributes of acid (cottage) and sweet (Edam and Cheddar) whey powders. The water holding capacity (WHC) of the whey powders was not affected by heating or pH value. The heated Cheddar whey powder had a significantly lower (p<0.05) WHC than that of the other wheys. Heating detrimentally impacted the emulsifying and foaming properties, On the other hand, heating significantly enhanced the heat stabilities (HS) of all powders, This was best demonstrated at the acidic pH values of 3.0 and 4.5, where the HS increased by 57 and 53, 181 and 167, and 31 and 48%, for the cottage, Edam, and Cheddar, respectively. Overall, this data provides useful insights into the manufacture of pasteurization and retort-stable whey powders.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.344-349
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• 1988

Proteolysis of 7S and 11S soy protein-rich fraction(PRF) with commercial proteases(alcalase and pronase) apperently increased protein solubility at pH 5, heat coagulation and calcium tolerence, while decreasing emulsifying capacity and foam stability regardless of the kind of protein and protease used. However, the proteolysis decreased the protein solubility of 7S PRF at pH 6 and 11S PRF at pH 4. The proteolysis of 11S PRF increased oil absorption and foam expansion, while slight decrease or almost no change was noted on 7S PRF. Heat stabilities of the emulsion and kinetic viscosities changed very little by the proteolysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.442-450
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• 2016

This study aims to determine the antimicrobial activity of fermented Cheonggukjang extract using the new Strain, Bacillus amyloliquefaciens NBF11-1, which was first found on the surface of the node part of bamboo stems, but has been studied very little so far. Bacillus subtilis NG24, which is the traditional fermented strain of Cheonggukjang, was selected as the control group and a comparative analysis was performed. The experimental method included measurements of the antimicrobial activity, minimum inhibitory concentration (MIC) and heat and pH stability. B. amyloliquefaciens NBF11-1 had stronger antimicrobial activity than B. subtilis NG24 against the gram-positive bacteria, C. perfringens and S. aureus and the gram-negative bacteria, A. faecalis and E. coli among the six species of pathogenic bacteria studied. When the minimum inhibitory concentration was measured, B. amyloliquefaciens NBF11-1 in C. perfringens, S. aureus, A. faecalis, and E. coli had an inhibitory effect at concentrations of 0.01 %, 0.21 %, 0.45 % and 0.29 %, respectively, compared to B. subtilis NG24. When the heat and pH stability was measured, B. subtilis NG24 and B. amyloliquefaciens NBF11-1 Cheonggukjang extract did not show any decrease in activity when held at a temperature of $121^{\circ}C$ for 15 minutes and at pH values ranging from 2 to 10 and were therefore considered to be relatively stable against heat and pH changes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1571-1579
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• 2009

Antioxidant activities of ethanol and water extracts from Orostachys japonicus leaf, stem, and root were determined by rancimat method, DPPH radical scavenging effect, chelating effect, and reducing power analysis. The highest total phenolic compound (TPC) as 14.6 mg/g of dry sample and the strongest antioxidant activity in rancimat method (value of AI 1.98), DPPH radical scavenging effect (96% in 4 mg/mL), and reducing power (1.50 in 4 mg/mL) were observed in ethanol extracts from Orostachys japonicus leaf. Heat and pH stabilities on antioxidant activity of Orostachys japonicus leaf extract were studied through TPC and DPPH radical scavenging effect. As a result, the extracts from Orostachys japonicus leaf showed high stability. These results suggest that extracts from Orostachys japonicus leaf can be potentially used as proper natural antioxidant in the food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.85-90
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• 1987

This experiment was carried out to study the preparations of red pepper oleoresin, the effects of pH and heat treatment on the stabilities of capsanthin and capsaicin in oleoresin state, and the interacting effects of ascorbic acid, metal salts and EDTA on the stabilities of capsanthin in the oleoresin-linoleate aqueous model system. The results were as follows: 1. Acetone was the most effective solvent to extract capsanthin and capsaicin from red pepper powder. The yield of oleoresin extracted with acetone was 14.27%. 2. Capsaicin was more stable at high temperature than capsanthin in oleoresin state. Capsanthin and capsaicin in oleoresin state were comparatively stable in the range (ron) pH 3 to pH 8. 3. Ascorbic acid acted as a prooxidant on the capsanthin oxidation reaction at concentrations up to $10^{-3}M$, but acted as an antioxidant at $10^{-1}M$. 4. The addition of $Cu^{+2}M$ and $Fe^{+3}M$ ions at all concentration increased the prooxidant activity on the degradation of capsanthin in oleoresin state. 5. EDTA showed a strong antioxidation the stability of capsanthin in oleoresin state.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.383-389
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• 2000

Stabilities to heat, pH, light were investigated about isolated red color pigment from the Korean Lithospermum erythrorhizon. The extracted pigment, acetylshikonin was stable heating at 40∼80$\^{C}$ for 1∼2 hours, hut it was specially unstable on the storage above 55$\^{C}$. The extracted pigment, acetylshikonin was stable on the sunlight under the red and green filters but unstable under the yellow and blue filters. The extracted pigment, acetylshikonin was stable under the pH of 4∼8 but unstable under the pH above 10. The extracted pigment, acetylshikonin was stable under the KCl and NaCl at concentration of 10$\^$-1/Mole. The pigment was very unstable under the CaCl$_2$, FeCl$_3$, CoCl$_2$, AlCl$_3$ and MnCl$_2$ at concentration of 10$\^$-1/Mole. The red pigment, acetylshikonin was stable under citric acid and acetic acid at concentration of 1 Mole. Especially, acetic acid was effective for the stability of the pigment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1427-1433
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• 2006

The antioxidant activity, nitrite scavenging effect, and angiotensine I-converting enzyme inhibiting activity of solvent extracts of soybean isoflavone were investigated. Also anticarcinogenic activities of them were examined by MTT assay using human cancer cell line. Isoflavone aglycones showed relatively high antioxidant activity in order of glycitein, genistein, and daidzein. Methanol extract of soybean actively scavenged free radicals and was shown excellent nitrite scavenging effect. Glycitein and methanol extract of soybean inhibited the growth of human cancer cell such as stomach carcinoma (SNU-1) and colon carcinoma (SNU-C4) effectively. Genistein, daidzein and methanol extracts of soybean inhibited the growth of cancer cell such as stomach carcinoma (SNU-1), but had weak activities to colon carcinoma (SNU-C4). To applicate the soybean isoflavone as an enhancer for food quality and processibility, the stabilities on heat and pH of isolated isoflavone, isoflavone in soybean flour and isoflavone concentrate of soybean were investigated. Stability of isoflavone concentrate of soybean was decreased in pH extreme (below 3, above 8) during sterilization, but isoflavone in soybean flour showed higher stability in all pH range. All kinds of isoflavone tested in this study were very stable during the heat treatment.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.250-257
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• 1987

The most active strain for the amylase activity from the native Youngkwang koji, was isolated and identified as Aspergjllus awamori. The optimal conditions for the production of ${\alpha}-amylase$ and glucoamylase were investigated and the properties of these enzymes were also examined. Maximum yields of ${\alpha}-amylase$ and glucoamylase were obtained at $30^{\circ}C$, pH 5.0 for days. The production of these two enzymes were increased with the addition of maltose, urea, $K_2HPO_4$, $MgSO_4{\cdot}7H_2O$, and $CaCl_2{\cdot}2H_2O$. The activities of these enzymes were maximized at $50^{\circ}C$, $pH\;5{\sim}6$. The heat stabilites of ${\alpha}-amylase$ and glucoamylase were maintained at $50^{\circ}C$ for 20min and 40min, respectively. Also, the addtion of $MgSO_4{\cdot}7H_2O$, $K_2HPO_4$, and $CaCl_2{\cdot}2H_2O$ salt increased the heat stabilities of these enzymes.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.507-513
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• 2000

A bacteriocin-producing organism, Enterococcus sp. T7, was isolated from human fecal samples. Bacteriocin T7, named tentatively as the bacteriocin, was produced by Enterococcus sp. T7 and it inhibited some strains of Lactobacillus. Staphylococcus, Enterococcus, and Streptococcus, but not all the lactococci and gram-negative bacteria tested. Bacteriocin T7 inhibited the growth of Listeria monocytogenes Scott A, but the degree of inhibition was less than those for other sensitive gram-positive vacteria. Bacteriocin T7 in MRS broth started to produce at the middle of the exponential growth phase and the inhibitory activity reached its maximum level during the stationary growth phase. Bacteriocin T7 was stable against heat treatments, pH variations (pH 2-10), and exposure to organic solvents. The molecular weight of bacteriocin T7 was estimated to be 6.500 Da by SDS-PAGe. All these facts, including physico-chemical stabilities, small molecular size, and inhibition of Kisteria monocytogenes, indicate that bacteriocin T7 is likely to be a member of the class IIa bacteriocins.