• Food Science and Biotechnology
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• v.17 no.1
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• pp.208-211
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• 2008

Previously, it has been reported that Aspergillus oryzae can efficiently degrade unpleasant odor components such as butyric acid and 3-methyl butanoic acid from meju, a major ingredient in both Korean soybean paste (doenjang) and soy sauce. In this study, the optimal manufacturing conditions for the production of superior quality Korean soybean paste and soy sauce were determined. Specifically, A. oryzae AJ 100 was utilized to improve the flavor of these products. Mixtures of Korean soybean paste and A. oryzae AJ 100 culture (2 : 1), and of Korean soy sauce and A. oryzae AJ 100 culture (5 : 1), were incubated for 2 weeks at $30^{\circ}C$, and showed improved flavor. Butyric acid and 3-methyl butanoic acid were clearly degraded under these culture conditions.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.5
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• pp.641-645
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• 2014

This study was performed to investigate the possibility of using three commercial bifidobacteria as a starter for soybean paste fermentation. In order to determine susceptibility to inhibition by high concentrations of salt in soybean paste, cell growth of three strains in sterilized soybean paste was analyzed. Bifidobacterium breve KCTC 5081 was the most resistant to salt, whereas Bifidobacterium bifidum KCTC 5082 showed low cell viability. Conversion efficiencies from glycoside isoflavone to aglycon isoflavone in soybean paste ranged from 11.3~28.6%, with Bifidobacterium longum KCTC 5734 the best strain. Therefore, B. longum KCTC 5734 may be used as a starter for Cheonggukjang fermentation, which is low-salt fermented soybean paste.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.648-660
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• 2014

Doenjang, a traditional Korean fermented soybean paste, is made by mixing and ripening meju with high salt brine (approximately 18%). Meju is a naturally fermented soybean block prepared by soaking, steaming, and molding soybean. To understand living bacterial community migration and the roles of bacteria in the manufacturing process of doenjang, the diversity of culturable bacteria in meju and doenjang was examined using media supplemented with NaCl, and some physiological activities of predominant isolates were determined. Bacilli were the major bacteria involved throughout the entire manufacturing process from meju to doenjang; some of these bacteria might be present as spores during the doenjang ripening process. Bacillus siamensis was the most populous species of the genus, and Bacillus licheniformis exhibited sufficient salt tolerance to maintain its growth during doenjang ripening. Enterococcus faecalis and Enterococcus faecium, the major lactic acid bacteria (LAB) identified in this study, did not continue to grow under high NaCl conditions in doenjang. Enterococci and certain species of coagulase-negative staphylococci (CNS) were the predominant acid-producing bacteria in meju fermentation, whereas Tetragenococcus halophilus and CNS were the major acid-producing bacteria in doenjang fermentation. We conclude that bacilli, LAB, and CNS may be the major bacterial groups involved in meju fermentation and that these bacterial communities undergo a shift toward salt-tolerant bacilli, CNS, and T. halophilus during the doenjang fermentation process.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.325-333
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• 2007

One bacterium with high proteinase production and spore-forming ability was isolated from korean traditional soybean paste(doenjang). The isolated strain was identified as Bacillus subtilis, based on gram-staining, biochemical properties and l6S rRNA gene sequencing, and designated as B. subtilis DJI. Its growth rate was very fast, and it reached its stationary phase within 9 h, and then started to form spores. Bacterial-koji and doenjang were prepared using B. subtilis DJI. Chemical components of the doenjang were determined after 2 months of aging period: amino nitrogen 507 mg%, crude protein 14.3%, crude fat 4.8% and water 54.9%. The composition of total and free amino acids and their ratios of doenjang were changed during the aging period. Among total amino acids in DJI doenjang, glutamic acid, aspartic acid, leucine and arginine were the major amino acids. The fibrinolytic activities of DJI doenjang and traditional doenjangs were 909.7 units/ml and $363.3{\sim}618.6\;units/ml$, respectively. Flavor compounds of DJI doenjang and traditional doenjang were extracted by SDE(simultaneous steam distillation and extraction), and analyzed by GC/MS; DJI doenjang possessed the typically favorable flavor compounds in traditional korean doenjang, with reduced off-flavor compounds.

• Food Science and Preservation
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• v.16 no.3
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• pp.348-354
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• 2009

We examined the quality characteristics of soybean paste prepared using Bacillus subtilisDH3, which expresses high levels of protease, and deep-sea water. The protease activity of Doenjang prepared with Bacillus subtilis DH3 was $278.83{\pm}1.68$ units/mL/min. Protease and angiotensin-converting enzyme (ACE) inhibition activities increased with aging, for up to 30 days. The electron-donating ability (EDA) of Doenjang PD(Doenjang fermented with protease prodncing B. Subtilis DH3) was $61.27{\pm}0.42%$, whereas Doenjang M (traditional Doenjang fermented with meju and salt) had a lower value of $14.47{\pm}0.41%$. The mineral content of Doenjang PD was higher than that of Doenjang M. The overall acceptability of Doenjang PD was better than that of Doenjang M.

• 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.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1258-1265
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• 2000

In oder to acquire microbial agents that can be utilized for control of aflatoxin produced by Aspergillus. flavus and Asp. parasiticus, antifungal bacteria were isolated. Antifungal bacteria was identified as Bacillus spp. based on morphology and physico-biochemical characteristics. Amount of aflatoxin $B_1$ from Doenjang(soybean paste) prepared with Asp. flavus, Asp. parasiticus, antifungal bacteria(Bacillus sp.), or mixture of Asp. flavus and Asp. parasiticus was 27.2 ppb, 30.3 ppb, 3.4 ppb, and 3.7 ppb, respectively. Aflatoxin $B_1$ was not detected from Doenjang(control) and Doenjang prepared with antifungal bacteria. Content and compositions of free sugars, fatty acid, organic acid and free amino acid in Doenjang prepared with Asp. flavus and Asp. parasiticus, antifungal bacteria and mixture of Asp. flavus and Asp. parasiticus were not significantly different. For volatile flavor compounds of Doenjang prepared with antifungal bacteria, 2-pentyl furan and butanoic acid were disappeared or reduced, while octadecene compounds were produced. However, those of Doenjang prepared with Asp. flavus or Asp. parasiticus and Doenjang(control) were not significantly different. These results suggested that the antifungal bacteria(Bacillus sp.) inhibited production of aflatoxin and that antifungal bacteria did not effect the quality of Doenjang.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.67-74
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• 1983

The studies on the color improvement of the Doenjang (two types of fermented soybean paste : soybean Doenjang and modified Doenjang) using various Aspergillus oryzae strains (6 strains : A, B, C, D, E, F) were conducted with the series of experiments of enzymatic activities (pretense, $\alpha$-and $\beta$-amylase), browning color formation (Lovibond color), major chemical components (amino nitrogen, reducing sugar and others) and sensory evaluation (color, taste and odor). Aspergillus oryzae 2157 (C strain) had a high potential for the color improvement of Doenjang products and was identified as non-browning strain during Doenjang fermentation and storage period. And also this strain was appeared to be in good enzyme activities and flavor characteristics.

• Korean journal of food and cookery science
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• v.32 no.6
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• pp.686-695
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• 2016

Purpose: This study aimed to investigate the quality characteristics of traditional and commercial soybean pastes (Doenjang) for development of traditional soybean pastes. Methods: Proximate compositions, amino acid nitrogen contents, pH, acidity, salt contents, chromaticity, viable bacteria and inorganic substance contents of nineteen traditional and three commercial Doenjang were investigated. Results: Analysis of proximate compositions indicated a significant difference between samples. In moisture content, D10 did not meet the standard of food codex. The contents of moisture, fat, protein and ash were slightly higher in traditional than commercial Doenjang. However, the carbohydrate content was 2-fold higher in commercial than traditional, and thus, the calories were also higher. The amino nitrogen content was lower in commercial than traditional Doenjang. pH, acidity and salt contents of Doenjang were pH 4.67-6.15, 1.53-3.29%, and 9.01-18.78%, respectively. pH and acidity showed no significant differences between traditional and commercial Doenjang, however, salt contents were significantly higher in traditional than commercial Doenjang. In case of chromaticity, the averages of L, a, b values were higher in traditional Doenjang. In microbiological analysis, total bacteria counts were higher in traditional than commercial Doenjang. The number of Bacillus cereus in D12 and D19 exceeded the standard of food codex. Staphylococcus aureust was undetected in all samples. The number of fungi varied widely between samples, with no detection in five traditional and all commercial Doenjang. Results of inorganic substance analysis indicated that contents of inorganic substances in Doenjang were in order of Na, K, Mg and Ca. Overall, Na content was higher in traditional Doenjang. Contents of inorganic substances showed wide variations in traditional Doenjang. Conclusion: For the development of traditional Doenjang, quality standardization and ensuring safety are considered necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.383-389
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• 1997

Doenjang(fermented soybean paste) was prepared by the series of processes including soaking, cooking, first fermentation(3 days at 30$\pm$2$^{\circ}C$) for the preparation of meju(soybean koji) after inoclulation of Aspergillus oryzae, and further fermentation (60 days at 30$\pm$2$^{\circ}C$) for the ripening after addition of salt 13% to meju. the crude phenolics extracted from defatted soybean and doenjang were fractionated onto the neutral phenolics(isofavonoids) and acidic phenolics(phenolic acids), respectively. Composition and antioxidative characteristics of phenolic fractions were determined. The neutral phenolic fractions contained genistin, genistein and daidzein; on the other hand, acidic phenolic fractions had syringic acid and seven other components. The content of genistin in doenjang dramatically decreased at the early stage of fermentation, whereas the content of genistein rather increased. In addition, the content of syringic acid of acidic phenolic fractions were increased during fermentation. These changes in individual phenolic components affected the antioxidative activity of neutral phenolics or acidic phenolics. antioxidative activity of phenolic compounds were evaluated during soybean fermentation. The antioxidative and free radical scavenging activity of neutral phenolic fractions and acidic phenolic fractions on linoleic acid autoxidation were also investigated.