• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.666-674
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• 2016

The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.

• Journal of Life Science
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• v.27 no.12
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• pp.1486-1493
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• 2017

Doenjang is a traditional korean fermented soybean paste made from meju (fermented soybean), which are fermented by diverse microorganisms including Bacillus subtilis and molds such as Rizopus, Mucor, and Aspergillus species The purpose of this study was to investigate the antiobesity effect of the black soybean doenjang (Korean fermented soybean pastes) in C57BL/6 mice. The anti-obesity effect was determined by measuring the release of adiponectin, leptin and adipogenic transcription factors by using reverse transcription-polymerase chain reaction and western blot. Weight gain was significantly reduced in the mice fed high fat diets (HFD) plus black soybean doenjang (HBD) compared to HFD mice. The HBD were also effective in improving the lipid profile. They significantly decreased the levels of serum triglyceride and cholesterol. In addition, they had a significantly down regulated impact on antiobesity factors; leptin level and increased adiponectin level. Also, mRNA and protein expression of two adipogenic transcription factors, SREBP-1c and $PPAR-{\gamma}$, in high fat with black soybean fed mice were markedly down regulated. These results indicate that the black soybean doenjang potentiates an anti-obesity effect by modulating lipid metabolism, thereby inhibiting adipogenic transcriptional activation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1194-1199
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• 2006

Effects of Korean traditional soybean fermented foods on weight reduction and lipid lowering activities were studied using Spraque-Dawley (SD) rats fed a high fat diet. The rats were raised for four weeks after adaptation period on either a normal diet (ND, based on the AIN-93 diet), high fat diet (HFD, supplemented with 12% lard oil in the ND), or diets containing 10% of freeze dried Doenjang, Chungkukjang, Kochujang, or Samjang to HFD. The final weight, food efficiency ratio (FER) and the weight of adipose tissue were decreased significantly by the consumption of Doenjang and Samjang, compared to HFD (p<0.05). The contents of cholesterol and triglyceride increased by HFD were reduced by the fermented foods in liver and perirenal fat tissues of the rats, especially Doenjang and Samjang diets showed high lipid lowering activity. And TG and cholesterol contents in the plasma serum were simillar trend to liver and perirenal fat tissue. These results suggested that Korean traditional soybean fermented foods, especially Doenjang showed the highest weight reduction and lipid lowering activities of the rats fed high fat diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.557-564
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• 2011

This study was performed to investigate changes in ${\gamma}$-aminobutyric acid (GABA) and isoflavones in traditional Korean Doenjang according to ripening periods. The traditional Korean Doenjang used in this research was produced at Seowon Agricultural Cooperative in Gangwon-do Province, and samples fermented for periods of 1, 3, 5, 7, and 10 years were used. Doenjang that was not fermented after production was used as a control group. The analysis results of general constituents indicated a decreasing tendency for moisture after a momentary increase until three years of fermentation. The pH and Hunter color values of the Doenjang samples decreased overtime. In the case of amino acids, generally there were no notable differences during fermentation, but glutamic acid, the precursor of GABA, significantly decreased with fermentation. GABA content for the control group was $24.9{\pm}0.8\;mg$/kg, while the traditional Korean Doenjang fermented for 1 year contained $43.8{\pm}0.2\;mg$/kg and after 3 years it increased to $120.6{\pm}3.9\;mg$/kg. Furthermore, samples fermented for 5 and 7 years contained $569.5{\pm}3.9\;mg$/kg and $930.7{\pm}7.1\;mg$/kg, respectively, and a 10 year old specimen had 77 times more GABA than the control group, with $1,938.7{\pm}4.8\;mg$/kg. This confirmed that GABA content increased with fermentation time. There were no significant differences in the isoflavone glycosides daidzin, genistin, and glycitin, but genistein and daidzein, which are aglycones, increased along with fermentation period by the actions of enzymes and microorganisms during fermentation.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.149-153
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• 2004

전통된장 제조방법으로서 원료 혼합비, 메주의 건조시간 및 온도, 메주와 된장의 발효 시간 및 온도, 된장 간장의 분리 여부, 된장 숙성(aging) 시간을 조사하였다. 혈액응고 저해 활성(anticoagulant activity)을 fibrin clotting assay법으로 분석하여 혈액응고 저해활성과 제법간의 상관 관계를 검토하였다. 숙성 기간이 길수록 혈액응고 저해활성이 높게 나타나는 경향을 보였으나 선형적인 상관관계보다는 비선형적으로 양의 상관관계를 갖는 것으로 판단되었다. 이상의 결과를 토대로 혈액응고 저해활성이 높은 2종의 된장시료를 선발하였으며 숙성기간이 180일 이상일 경우 전통된장의 혈액응고 저해활성이 높은 것으로 판단되었다.

• Food Science and Preservation
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• v.10 no.2
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• pp.213-218
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• 2003

In order to develop new functional doenjang, two types of medicinal herb doenjang were prepared with several medicinal herbs, bamboo salts and meju and then changes of its physiological functionalities were investigated during 6 months of fermentation. Antihypertensive angiotensin converting enzyme(ACE) inhibitory activities of medicinal herb doenjangs were decreased to 39.0∼5l.7% from 61.7∼72.5% after 6 months of fermentation. Fibrinolytic activity and electron donating ability of medicinal herb doenjangs were showed 10.4∼11.3 U and 96.3∼99.1% after 6 months of fermentation, respectively. SOD-like activity of medicinal herb doenjangs were also showed approximate 10% and tyrosinase inhibitory activity of 20$^{\circ}C$ -water extracts of medicinal herb doenjang(I) was increased up to 97.6% from 12.9% after 6 months of fermentation. Crude protein content and total sugar content of medicinal herb doenjangs were approximate 14% and 33%, respectively, which were higher than those of traditional doenjang.

• Food Science and Preservation
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• v.21 no.3
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• pp.434-441
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• 2014

This study investigated the quality characteristics and sensory evaluation of Doenjang samples made of soybean koji and prepared with Bacillus subtillus 3-B-1 and/or Aspergillus oryzae 6-M-1 isolated from traditional Meju, to replace the koji with wheat flour. Among the quality characteristics of doenjang during its fermentation at $30^{\circ}C$ for 40 days, its moisture decreased by degrees, but its amino-type nitrogen and reducing sugar increased by degrees. The color of the doenjang made of koji and prepared with Aspergillus oryzae 6-M-1 changed more significantly than that of the doenjang with Bacillus subtilis 3-B-1. The viable cell and mold counts increased by degrees during the fermentation. The results of the sensory evaluation of the doenjang made with koji and prepared with Aspergillus oryzae 6-M-1 did not significantly differ from those of the doenjang with Bacillus subtilis 3-B-1 and of the commercial doenjang. These results showed the possibility of preparing doenjang with soybean koji instead of wheat flour koji.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1397-1404
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• 2014

A few starters have been developed and used for doenjang fermentation but often without safety evaluation. Filamentous fungi were isolated from industrial doenjang koji, and their potential for mycotoxin production was evaluated. Two fungi were isolated; one was more dominantly present (90%). Both greenish (SNU-G) and whitish (SNU-W) fungi showed 97% and 95% internal transcribed spacer sequence identities to Aspergillus oryzae/flavus, respectively. However, the SmaI digestion pattern of their genomic DNA suggested that both belong to A. oryzae. Moreover, both fungi had morphological characteristics similar to that of A. oryzae. SNU-G and SNU-W did not form sclerotia, which is a typical characteristic of A. oryzae. Therefore, both fungi were identified to be A. oryzae. In aflatoxin gene cluster analysis, both fungi had norB-cypA genes similar to that of A. oryzae. Consistent with this, aflatoxins were not detected in SNU-G and SNU-W using ammonia vapor, TLC, and HPLC analyses. Both fungi seemed to have a whole cyclopiazonic acid (CPA) gene cluster based on PCR of the maoA, dmaT, and pks-nrps genes, which are key genes for CPA biosynthesis. However, CPA was not detected in TLC and HPLC analyses. Therefore, both fungi seem to be safe to use as doenjang koji starters and may be suitable fungal candidates for further development of starters for traditional doenjang fermentation.

• Food Science and Preservation
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• v.11 no.4
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• pp.461-467
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• 2004

Antioxidant effect of traditional doenjang(TD) was reduced by increasing of maturation period. Methanol fractionate of TD matured for 1 year showed strong antioxidant effect against linoleic acid, following the order of hexane and water layer. Antioxidant effect in lipophilic and hydrophilic extracts of TD were gradually increased according to increasing maturation period, whereas their values or two extracts were lower than those or fractionates from TD. Hydrogen-scavenging effect in hydrophobic extract, methanol and butanol fractionates of TD were much higher than those of the other samples. Chloroform and ethylacetate fractionates were markedly lower in the range of $10.57{\sim}22.84\%\;and\;7.82{\sim}22.58\%$, respectively. Anticarcinogenic effect of extracts and fractionates from TD were higher in water fractionates for A549 cell (human lung carcinoma) and methanol fractionates fur MCF-7 cell (human breast adenocarcinoma). Especially, inhibitory effect for growth of cancer cell was increased by the increasing maturation period of TD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.211-217
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• 2000

To standardize quality characteristics of commercial doenjang prepared by traditional method, general components, organic acids, amino acids and fatty acid composition were investigated. Moisture, crude protein, crude lipid, titratable acidity (expressed as milliliter of 0.1 N NaOH), acid value and salinity were 54.7%, 13.8%, 8.0%, 14.4mL, 45.7mg/g and 11.8%, respectively. The content of amino type nitrogen was 345.3mg% (w/w) in the range of 207.6 to 443.5mg% being 1.1~2.2-fold for all samples. Average value of Hunter color for L(lightness), a(redness) and b(yellowness) were 37.4, ＋9.7 and ＋21.3, respectively. Browning index value(expressed as optical density at 425 nm) of water-soluble compound(2.58) was above 7.1 times higher than that of the water-insoluble compound(0.38). Total contents of free and total amino acid were 3.81 and 9.72%, respectively, and then the former(1.1~3.7 times) was more different in all samples tested than that of the latter(1.1~2.0 times). Among amino acids, glutamic acid was abundant and its content of free and total amino acids was 0.57 and 1.24%, respectively. Of organic acids, lactic acid was the most abundant being 0.34%(average) and ranged from 0.15 to 0.86%. Linoleic acid(52.17%, as area%) was the highest content of the total fatty acids. Unsaturated and polyunsaturated fatty acids were 83.89 and 61.189%, respectively. Polyunsaturated fatty acid was markedly different among all samples and ranged from 51.52 to 64.91%.