• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1270-1279
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• 2011

Bealmijang is a short-term aged paste made from meju, which is a brick of fermented soybeans and other ingredients. Different types of bealmijang are available depending on the geographic region or ingredients used. However, no study has clarified the microbial diversity of these types. We identified 17 and 14 fungal species from black soybean meju (BSM) and buckwheat meju (BWM), respectively, on the basis of morphology, culture characteristics, and internal transcribed spacer and ${\beta}$-tubulin gene sequencing. In both meju, Aspergillus oryzae, Rhizopus oryzae, Penicillium polonicum, P. steckii, Cladosporium tenuissimum, C. cladosporioides, C. uredinicola, and yeast species Pichia burtonii were commonly found. Moreover, A. flavus, A. niger, P. crustosum, P. citrinum, Eurotium niveoglaucum, Absidia corymbifera, Setomelanomma holmii, Cladosporium spp. and unclassified species were identified from BSM. A. clavatus, Mucor circinelloides, M. racemosus, P. brevicompactum, Davidiella tassiana, and Cladosporium spp. were isolated from BWM. Fast growing Zygomycetous fungi is considered important for the early stage of meju fermentation, and A. oryae and A. niger might play a pivotal role in meju fermentation owing to their excellent enzyme productive activities. It is supposed that Penicillium sp. and Pichia burtonii could contribute to the flavor of the final food products. Identification of this fungal diversity will be useful for understanding the microbiota that participate in meju fermentation, and these fungal isolates can be utilized in the fermented foods and biotechnology industries.

• Journal of the Korean Society of Food Culture
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• v.10 no.5
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• pp.427-434
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• 1995

The preparation method for traditional kochujang (fermented hot pepper-soybean paste) at home were surveyed by 1,436 housewives through the country by premade questionnaires. The kochujang meju (Korean style soybean Koji for kochujang) were made by solely soybean (45.3% of respondents) or soybean with rice (26.3%) from September to November (52.2%) or December to February (32.7%). The shape of meju was either doughnut (28.4%) or brick (25.6%) type. Kochujang making seasons were either from March to May (56.6%) or December to February (25.0%) and it was prepared in proportion of mostly $6{\sim}10%$ meju powder (32%) with over 20% of red pepper powder (57.2%) prepared by seed removed dry red pepper. Subsidiary ingredients for kochujang making were boiled waxy rice (73.5%), malt (33.3%), corn syrup (18.9%) or corn syrup with malt (21.9%). After mixing all ingredients, kochujang in clay pot were occasionally exposed to the sun for fermentation for $3{\sim}4$ months (35.0%) or $1{\sim}2$ months (34.7%).

• Applied Biological Chemistry
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• v.28 no.4
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• pp.226-232
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• 1985

Changes in lipid and fatty acid composition in Korean native Meju were investigated at one week interval over 6 weeks of fermentation. For the systematically, salicic acid column chromatography and gas liquid chromatography were used. Following results were obtained. 1. The lipid fraction obtained from the soared soybean and the cooked soybean were mainly composed of $72.47%{\sim}92.35%$ of neutral lipid, phospholipid and glycolipid were 4.64% and 4.88%, respectively. During fermentation period, lipid content decreased to 80.59%, but glycolipid and phospholipid contents increased. 2. The triglyceride contents of nonpolar lipids prepared from the cooked soybean and the soaked sobean was 89.66% and 87.83% respectively. Free fatty acid, diglyceride and sterol contents increased during fermentation, whereas triglyceride content decreased. 3. Lipids extracted from the soaked soybean and the cooked soybean were composed of 54.58% linoleic acid, $22{\sim}20%$ oleic acid, $10{\sim}12%$ palmitic acid and $3{\sim}5%$ stearic acid. 4. During the Korean native Meju fermentation in palmitic acid decreased from the second week and stearic acid through $3rd{\sim}4th$ week. Oleic acid and linoleic acid content decreased gradually, but linolenic acid content increased. 5. During the fermentation, myristic acid content of glycolipid fraction increased. Lipase activity reached to the maximum at the 3rd week.

• Korean journal of food and cookery science
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• v.24 no.2
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• pp.243-250
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• 2008

This study examined the quality characteristics of soybean pastes that were prepared using different ratios of whole soybean meju inoculated with three different types of microbial strains. The five samples were prepared with meju inoculated with Aspergillus oryzae KFRI 995, Bacillus subtilis F4005, mixture with A. oryzae KFRI 995 and B. subtilis F2315, mixture with A. oryzae KFRI 995 and B. subtilis F4005, and mixture using all three strains, respectively. Over two months of fermentation, pH gradually decreased, whereas total acidity increased. And across samples and fermentation periods, there were no considerable changes in moisture or crude protein. In all five samples, amino-type nitrogen levels increased approximately 2- to 3-fold as compared to initial levels; the sample inoculated with A. oryzae KFRI 995 showed the highest level (205.2 mg%) of amino-type nitrogen. Throughout fermentation, the five samples displayed differences in their reducing sugar levels according to the inoculated microorganisms. The lowest level of lightness and highest level of redness occurred in the sample inoculated with B. subtilis F2315 showed a lowest level in lightness and a highest level of redness, indicating a strong browning reaction. Finally, the samples inoculated with A. oryzae KFRI 995 and B. subtilis F4005, respectively, showed had similarly high preference scores as compared to the other samples.

• Food Science and Preservation
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• v.18 no.3
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• pp.397-406
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• 2011

To industrialize meju, four kinds of meju (Korean-style soybean koji) were made with humidity-controlled fermentation for 12 days at $28^{\circ}C$ after they were inoculated with selected strains such as Aspergillus otyzae (AO meju), Aspergillus sojae (AS meju), combined Aspergillus sojae and Bacillus subtilis (ASBS meju), and combined Aspergillus oryzae and Bacillus subtilis (AOBS meju) as starter microorganisms. The changes in the quality characteristics in the four kinds of meju were investigated during fermentation. Their enzyme activities were compared with those of the traditional meju that is made in Sunchang Folk Village according to the traditional method. In the meju that were inoculated with selective strains, the aerobic bacteria counts and mold counts exceeded 8 log cfu/g and 6 log cfu/g respectively, which were the highest fermentation values after 2 days. The aerobic bacteria counts were maintained from 2-day to the 12-day fermentation. The mold counts tended to decreased gradually after the 2-day fermentation. The amino-type nitrogen contents reached 430.5-577.5 mg%, which were the highest values after 2-day fermentation. The neutral protease activities of these mejus had the highest levels in the following order: traditional meju, $1,258.0{\pm}38.8$; AS meju, $1,238.3{\pm}38.6$; AO meju. $1,204.1{\pm}24.1$; ASBS meju, $1,040.6{\pm}10.6$; and AOBS meju, $1,033.5{\pm}11.2$ unit/g. The acidic protease activities of these meju had the highest levels in the following order: AO meju, $1,030.1{\pm}19.1$, traditional meju, $1,007.7{\pm}30.5$; AS meju, $990.9{\pm}25.0$; AOBS meju, $910.9{\pm}15.3$; and ASBS meju, $888.2{\pm}15.7$ unit/g.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.56-62
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• 2017

The purpose of this study was to determine how seeding time changes the properties of soybean products meju and doenjang. Soybeans were seeded on the last day of May (5L), on the mid day of June (6M), and on the last day of June (6L), respectively. The 5L soybeans experienced a distinguishing hot and humid climate at the ripening stage, and these climate conditions resulted in smaller seed sizes. Fermentation briskly progressed in all doenjang until 120 days, and the 5L doenjang exhibited the lowest fermentation efficiency. The 5L soybeans showed the highest GABA, polyphenol contents, and ACE inhibitory activity, and the 6M soybeans showed the highest radical scavenging activity among the groups tested. In doenjang, the functional properties generally increased as the aging time approached the $120^{th}$ day, and the 6M doenjang showed the highest functional properties at the $120^{th}$ day. Therefore, 6M soybeans had the most appropriate characteristics when producing doenjang.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.293-295
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• 2019

Enterococcus faecalis strain DM01 was isolated from meju, a traditional Korean fermented soybean product. The strain did not exhibit resistance to eight antibiotics (ampicillin, chloramphenicol, ciprofloxacin, erythromycin, gentamicin, penicillin G, tetracycline, and vancomycin), biofilm formation, and hemolytic activity. The genome of strain DM01 consists a single circular 2,785,968-bp chromosome with a G + C content of 37.68%. The complete genomic sequence of strain DM01 provides genetic information to support the absence of antibiotic resistance, biofilm formation, and hemolytic activity.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.405-409
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• 1998

This work was carried out to investigate the behavior of sugars contained in raw soybean during cooking and meju preparation processes, and the effects of sugar addition to the raw kanjang digestion liquor made from G8 and SB meju on the lactic acid and alcoholic fermentation of kanjang. Sharp reduction in sugars content in soybean during cooking and meju preparation process was observed. Rapid lactic acid and alcoholic fermentation in the G8 and SB kanjang with 5% added glucose was observed but not in the corresponding kanjang without sugar addition after inoculation of Pediococcus halophilus, Zygosaccharomyces rouxii and Candida versatilis starter culture to the low-salted raw kanjang digestion liquor made respectively from G8 and SB meju. 0.46% and 0.88% of lactic acid and 1% and 2% of alcohol content in the G8 and SB kanjang respectively was observed 160 hours after the inoculation of the lactic acid bacteria starter culture.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.916-924
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• 2017

Eighty-five Enterococcus faecalis isolates collected from animals (40 isolates), meju (a Korean fermented soybean product; 27 isolates), humans (10 isolates), and various environmental samples (8 isolates) were subjected to multilocus sequence typing (MLST) to identify genetic differences between samples of different origins. MLST analysis resulted in 44 sequence types (STs), and the eBURST algorithm clustered the STs into 21 clonal complexes (CCs) and 17 singletons. The predominant STs, ST695 (21.1%, 18/85) and ST694 (9.4%, 8/85), were singletons, and only contained isolates originating from meju. None of the STs in the current study belonged to CC2 or CC9, which comprise clinical isolates with high levels of antibiotic resistance. The E. faecalis isolates showed the highest rates of resistance to tetracycline (32.9%), followed by erythromycin (9.4%) and vancomycin (2.4%). All isolates from meju were sensitive to these three antibiotics. Hence, MLST uncovered genetic diversity within E. faecalis, and clustering of the STs using eBURST revealed a correlation between the genotypes and origins of the isolates.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.277-282
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• 1999

This study was carried out to clarify the microorganisms which participated in the fermentation of kanjang. The changes in the viable cell counts of total aerobic bacteria, lactic acid bacteria and yeasts for raw soybean, soybean during cooking, meju during cultivation, and kanjang mash during maturing were investigated along with the changes in components during those periods. Lactic acid bacteria that were found to be $6{\times}10^2\;CFU/g$ in raw soybean were disappeared after cooking process, but total aerobic bacteria were diminished from $1.9{\times}10^6\;CFU/g$ to $10^2\;CFU/g$. Aerobic bacteria of inner and outer parts of meju increased to more than $10^9\;CFU/g$. The higher viable cell counts of lactic acid bacteria in the inner parts of meju were observed than those in outer ones. On the contrary, significantly higher viable cell counts of yeasts in the outer parts of meju were found. Total nitrogen content and color density of kanjang increased by using meju with extended cultivation periods. No significant differences were observed in microbial counts between kanjang mash with aeration and non-aeration during kanajng mash maturing.