• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.448-454
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• 1998

Meju for doenjang and kochujang was prepared as a model at Sunchang areaand monitored with major changes. Kochujang meju was prepared on September 12 and doenjang meju on November 12, 1995. Kochjang meju was found to be naturally fermented at 80~90% RH, 15~2$0^{\circ}C$ and doenjang meju was at 80~90% RH and 0~5$^{\circ}C$. The shapes of kochujang meju and doenjang meju were doughnut-type and rectangular, respectively. Weight losses during fermentation were 48% and 28%, respectively. The pH drop and acip production of kochujang meju were negligible. However, pH of doenjang meju decreased from 6.29 to 5.88 and acidity increased from 0.08 to 0.23% as lactic acid. Protein in meju was found to be rapidly solubilized during the early stage of fermentation. Soluble protein cotents of kochujang meju after 7 days and 60 days were 8.23%, respectively. The doenjang mejus were 2.15% after 20 days and 5.72% after 60 days. Soluble suger content increased with the fermentation time. The soluble sugar content was higher in kochjang meju. Acidic protease was highly produced during meju fermentation. $\alpha$-Amylase and $\beta$-amylase were detected in the kochujang meju, of which glutinous rice consisted, but negligible in doenjang meju. Lipase was detected in kochujang meju, but was, negligible in doenjang meju. Microbial population increased drastically after 7 days of fermentation in kochujang meju and 20 days of fermentation in doenjang meju.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.148-155
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• 1991

Lipid oxidation and browning during fermentation of domestic Meju and Doenjang were examined in order to elucidate the antioxidative effects of browning products and phenol compounds from Meju and Doenjang. Peroxide values of lipids from Meju were detectable and slightly increased until 3 weeks of fermentation, but started to be decreased after 3 weeks of fermentation and notdetectable after 6 weeks. Peroxides were not detected in Doenjang during the whole fermentation, but started to be decreased after 3 weeks of period of 22 weeks fermentation. Carbonyl value were increased during the whole period of Meju fermentation, but started to be decreased at the early stage of Doenjang fermentation. Hydrophilic fraction of browning products from Meju was much higher than lipophilic fraction and the former fraction was dramatically increased at the early stage of the fermentation. But the both fractions maintained high values during Doenjang fermentation. Hydrophilic browning products and phenol and phenol compound in Meju showed strong antioxidative against linoleic acid.

• 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.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1405-1409
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• 1999

This study was conducted to investigate the isoflavone contents of soybeans, Meju, and Doenjang. $The\;{\beta}-glucosidase$ activities were also determined and characterized in soybeans, Meju, and Doenjang. The total concentration of daidzein was 406 mg/kg of soybeans, 433 mg/kg of Meju, and 538 mg/kg of Doenjang. Aglycones compose 26.03% of total isoflavones in soybeans, 61.96% in Meju, and 107.68% in Doenjang. The total concentration of genistein was 484, 200 and 538 mg/kg of soybeans, Meju and Doenjang, respectively. Aglycones compose 19.49% of total isoflavones in soybeans, 68.52% in Meju, and 85.26% in Doenjang. The ${\beta}-glucosidase$ activity was detected in soybeans (5.65 units/mg protein), Meju (2.04 units/mg protein), and Doenjang (0.69 units/mg protein). The optimal pH of ${\beta}-glucosidase$ activities were $6.5{\sim}7.0$ and the optimal temperature of ${\beta}-glucosidase$ activities was $50^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.247-253
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• 1996

Changes in microorganisms, enzyme activities and major components of two types of Doenjang prepared with spring Meju and autumn Meju and Kochujang were investigated during 4 months of fermentation. The viable cell counts of aerobic bacteria in Doenjang and Kochujang were increased up to 60 days of fermentation, but viable cell counts of anaerobic bacteria did not show remarkable changes during fermentation. Viable cell count of yeast showed a rapid increase up to 15 days of fermentation in Doenjang and 60 days in Kochujang. It was found that $\alpha$-amylase activity of autumn Meju Doenjang and glucoamylase activity of Kochujang were higher than the other. Acidic and neutral protease showed the highest activity during 15-30 days of fermentation. The pH of Doenjang was increased up to pH 7.0 until 60 days of fermentation, but pH of Kochujang gradually decreased during fermentation. Moisture content of spring Meju Doenjang and Kochujang decreased to 40% during ferme- ntation and reducing sugar content of Kochujang increased up to 15 days of fermentation, but decreased after that.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.792-798
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• 1994

In order to investigate the antioxidant activity of phenolic compounds contained in domestic Meju and Doenjang , the methanolic extract from defatted Meju and Doenjang was fractionated into the phenolic acid and the isoflavone fractions by alumina column and polyamide-6 column chromatography, respectively. Both phenolic acid and isoflavone fractions exhibited an identical antioxidative effect against the oxidation of linoleic acid. GC analysis revealed that the phenolic acid fractio contained vanillic , chlorogenic ,p-coumalic , ferulic, and caffeine acid. The content of caffic acid was greater than 70% in the phenolic acid fraction and the content of vanillic and chlorogenic acids were disappeared during fermentation, and thus, the facts are thought to be reasons for the low antioxidant activity of the phenolic aicd fraction from Doenjang. Similarly, the isoflavone fraction cotained daidzin, glycitin-65-0 glucosider and genistin and their aglycons such as daidzein, glyciten and genistein. The content of daidzin and genistin in Meju dramatically decreased at the early stage of fermentation ,whereas the content of daidzein an dgenistein rather increased ; however, these change in isoflavone contents did not affect the antioxidant activity of isoflavone fractions.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.90-97
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• 2009

Changes in the quality characteristics of doenjang prepared with a meju containing components of Acanthopanax senticosus, Angelica gigas and Corni fructus during storage were evaluated. Three types of doenjang produced using each of these components showed lower Hunter's L and a values than the values of the control during the initial stage of storage: however, these values were similar to those of the control after 60 days of storage. Doenjang containing A. gigas showed a similar degree of browning to that of the control during the early stage of storage, while the degree of browning observed in the other samples was much higher than that og the control during this period. Despite these initial differences, the browning in all samples became similar after extended storage. The level of acidity increased gradually for up to 60 days, after which it decreased slightly. The pH of all treatments decreased with storage time. The amino-N contents of all types of doenjang increased gradually, reaching peak values after 60 days. Doenjang with A. senticosus and A. gigas had a strong characteristic flavor that reduced the native flavor of doenjang. Doenjang with C. fructus showed a similar overall palatability to that of the control.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.354-358
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• 2019

In order to evaluate the migration of fungi into doenjang from its materials, meju and solar salt, microbial communities were analyzed using pyrosequencing. Dominant fungi of meju were Botrytis spp. (57.94%) and Dothiorella samentorum (24.08%). Unidentified fungal species (37.53%), unassigned species (32.60%) and several fungal species of small portion were identified in solar salt. In doenjang, Candida versatilis were predominantly detected (92.62%). Non-halophilic mold were dominantly identified from meju (low-salt fermented soybean), while halophilic bacteria and archaea for solar salt and salt-tolerance fungi such as C. versatilis for doenjang (high-salt fermented soybean) were frequently detected. These results implied that most predominant fungal species might not be migrated from meju and/or solar salt into doenjang.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.266-271
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• 1994

In order to investigate the effects of the mixing ratio of rice on Doenjang, Meju Doenjang and Koji Doenjang were prepared respectively with oaring mix ratio of raw materials. The following results were obtained, after fermentation of up to 3 months. Significant differences between the kinds of Doenjang were not found in moisture and salt contents. Protein solubility $(water\;soluble\;nitrogen/total\;nitrogen{\times}100)$ was $32{\sim}50%$ and $14{\sim}24%$ in Koji Doenjang and Meju Doenjang, respectively. Protein digestibility $(formol\;nitrogen/total\;nitrogen{\times}100)$ was similar to the tendency of protein solubility. Reducing sugar content was $5{\sim}6%$ in Meju Doenjang, while $19{\sim}21%$ in Koji Doenjang. As the mixing ratio of rice increased, reducing sugar content also increased. Sensory evaluation showed that Koji Doenjang was desirable than Meju Doenjang and the mixing ratio of 20% rice was recommened for Koji Doenjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.557-565
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• 1992

Volatile components of domestic Meju and Doenjang were extracted by simultaneous steam distillation extraction, and analyzed by GC-MS. Sixty-four kinds of compounds were identified from neutral fraction. The contents of pentanal, hexanal and 1-octen-3-ol were high in cooked soybean while those of 3-methylbutanal and 1-butanol were high in Meju. In the case of Doenjang, so many compounds including acetic acid, ethylester were identified which was not appeared in Meju. The main compounds in Meju were 3-methyl-1-butanol, 2-furancarboxyaldehyde, 1-octen-3-ol, benzeneacetaldehyde, methyloctadecadienoate and methyloctadecenoate. Of the eleven compounds identified from basic fraction, the contents of 2,6-dime-thylpyrazine, trimethylpyrazine and tetramethylpyrazine were high in Meju and Doenjang. Nine kinds of compounds were identified from phenolic fraction and appeared that 4-vinylphenol and p-ethylguaiacol were major compounds in Meju and Doenjang. Fifteen kinds of volatile compounds were contained in acidic fraction. Only four acidic compounds were identified in cooked soybean and Meju, but in Doenjang ten compounds were identified which did not appeared in other samples. Among them pentadecanoic acid was major compound.