• Food Science and Biotechnology
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• v.17 no.2
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• pp.442-445
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• 2008

Meju, a major ingredient of doenjang which is a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in natural environment in which steamed soy was exposed to airborne microorganism, in particular, fungi. Total isoflavone content was reduced from 1,849 mg/kg of cooked soy to 816 mg/kg of meju at the $90^{th}$ day of fermentation. Total glycosides and aglycones of isoflavones in meju were 1,827 and 22 mg/kg at 0 day and changed into 487 and 329 mg/kg at the 90th day of fermentation, respectively. Meanwhile, the ratio of glycosides to aglycones of isoflavones was not changed during aging of doenjang but remained relatively constant with 592 and 644 mg/kg aglycones at the 0 and $160^{th}$ day, respectively. When cooked soy was fermented with Aspergillus oryzae and Aspergillus flavus, isoflavone profiles were significantly different from each other while A. oryzae caused more extensive metabolism of isoflavones than A. flavus.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.241-248
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• 1983

Lupin seed was used to make Meju, the fermentation starter for Korean soybean sauce and paste in substitution for soybean and the fermentation characteristics were compared with those of soybean. Mejus were prepared by in-oculating Asp. oryzae on the cooked whole beans. The dried Mejus were used for making fermented bean sauce and paste by mixing with brine and subsequent ripening for 4 weeks. In general the protease activity and amylase activity-during ripening were higher in lupin seed Meju than those of soybean Meju. The increase in protease activity correlated to the increase in $\alpha$-amino nitrogen content of the fermented paste and sauce. The development of dark-brown color of the sauce during ripening faster with lupin seed Meju compared to soybean Meju. In sensory evaluation the flavor score of lupin seed sauce and paste was slightly lower than that of soybean products but the overall quality of fermented lupin seed sauce was acceptable.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.751-759
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• 2018

This study was conducted to investigate quality characteristics of red bean gochujang prepared with different ratios of meju for eight weeks. We determined quality characteristics such as pH, moisture content, total microbial flora counts, amino-type nitrogen content, total polypenol content, and antioxidant activity. The pH decreased by fermentation period, whereas total acidity was 0.36~0.39% in the early stage of fermentation, 0.63~1.16% at four weeks of fermentation, and decreased to 0.43~0.65% after the eighth week of fermentation. Moisture content of the control (no red bean, no rice) decreased 62.13% to 50.93%, but in case of the treatment, it slightly decreased. Total cell counts revealed similar tendency at the beginning of fermentation, and at eight weeks of fermentation. In case of lactic acid bacteria, all samples except RB-1.5 (gochujang added meju made of mixing ratio of rice:soybean:red bean (1:2:1.5) slightly increased. Amino nitrogen and total polyphenol of all samples increased in the fermentation period, especially RB-1.5 sample had the highest levels than other samples. By increasing the amount of red bean, DPPH radical scavenging activities increased. In taste sensing analysis, all treat samples except RB-1.5 revealed lower sourness than the control. Also, in case of bitterness, all samples revealed low content than the control. So, by adding red bean, it can enhance taste and function of gochujang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1066-1071
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• 2012

In this study we investigated the change in antigenicity and allergenicity of Meju, a traditional Korean soybean product, by fermentation via 3 different microorganisms. The steamed soybeans were fermented with Lactococcus lactis subsp. lactis and/or Aspergillus oryzae and/or Bacillus subtilis. Proteins in soybean were degraded after fermentation. Antigenicity or allergenicity were analysed by immunoblotting and ELISA using soybean protein-specific polyclonal antibodies or soybean allergic patient sera. The best degradation was achieved by three step fermentation using nisin-producing Lactococcus lactis subsp. lactis IFO12007, A. oryzae and B. subtilis. Allergenicity and antigenicity were also starkly reduced after three step fermentation. The three-step fermentation method developed in our lab suggests an excellent alternative to reduce the allergenicity of soybeans.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.604-613
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• 1994

Hydrophilic brown pigments(HBPs) produced during fermentation and aging the domestic Meju and Doenjang were separated by dialysis and chromatography , and their antioxidant activity were measured . The chemical properties of HBP were determined by UV and IR spectrophotometry. HBPs contents were found to be 93.1 mg/g and 183.2mg/g in Meju fermentated for 30 days and 80 days , respectively. The ratio of dialysate to diffusate of the HBPs were appeared to be 70 : 30 and 87 :13 in the Meju fermented for 30 days and 80 days, respectively. and the rtio in the Doenjang aged for 60 days was 91 :9 , indicating that dialysate slowly days, respectively, and the ratio in the Doenjang aged for 60 days was 91 : 9, incidatin that dialysate slowly increased by the fermentation . Both portion exhibited strong antioxidant activity, but more stronger antioxidant activity was found in the dialysate. DEAE-celluose column chromatography showed that dialysate contained more materials eluted by 0.01-0.03M HCI solution than 0.01M acetate buffer, but diffusate showed opposite results. The degree of browning reaction and antioxdiant activity found in the fraction eluted by HCI solution was stronger than that of the fraction eluted by acetate buffer. The fraction eluted from DEAE-cellulose column chormatogrphy was further fractionaged by TLC and found that strong antioxidant activity was present in the fractions which did not possess fluorescenece and showed a negative ninhydrin reaction. TLC fractions of HCI eluant in Meju exhibited a strong absorbance at 260-280nm, but most of other fractions did not show any absorbance at UV region. TLC fractions from dialysate and diffusate showed fairly identical IR spectrum with absorbance at 3400cm-1, 2800cm-3000cm -1, 1600cm, -1 1400cm-1 and 1100 cm-1 , however, in addition to these absorbances, the spectrum from HCI eluant of Meju exhibited a strong absorbance at 1750cm , indicating the carbonic acid or carbonate ester.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.378-383
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• 2007

To study the characteristics and processing of Kochujang which is rapidly fermented by commercial enzymes, three kinds of Kochujang(KP-FA, KP-FN, and KP-BN) using commercial proteases and one Kochujang(KM) using Meju were prepared and their qualities investigated. There were only small differences in pH and acidity between each Kochujang. The moisture contents were high tendency in the three kinds of Kochujangs using the commercial proteases at 20 days of fermentation. Reducing sugars had a tendency to decrease during the fermentation in the Kochujangs using the proteases. During the first half of fermentation, the Kochujangs made with proteases showed higher amino nitrogen contents than the Kochujang(KM) made using Meju. Acidic protease activity was high in KP-FA at 20 days of fermentation and neutral protease activity was high in KP-FN and KP-BN at the beginning of fermentation. The Kochujangs made using the proteases, through 20 days of fermentation, obtained high preference in the sensory evaluation for color, texture, and overall acceptability. However, the hot taste was stronger in these Kochujangs during the fermentation.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.251-261
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• 2017

Initially, we screened 18 Aspergillus sojae-like strains from Aspergillus spp. isolated from meju (Korean traditional fermented soybean brick) according to their morphological characteristics. Because members of Aspergillus section Flavi are often incorrectly identified because of their phylogenetic similarity, we re-identified these strains at the morphological and molecular genetic levels. Fourteen strains were finally identified as A. sojae. The isolates produced protease and ${\alpha}-amylase$ with ranges of 2.66-10.64 and 21.53-106.73 unit/g-initial dry substrate (U/g-IDS), respectively, which were equivalent to those of the koji (starter mold) strains employed to produce Japanese soy sauce. Among the isolates and Japanese koji strains, strains SMF 127 and SMF 131 had the highest leucine aminopeptidase (LAP) activities at 6.00 and 6.06 U/g-IDS, respectively. LAP plays an important role in flavor development because of the production of low-molecular-weight peptides that affect the taste and decrease bitterness. SMF 127 and SMF 131 appeared to be non-aflatoxigenic because of a termination point mutation in aflR and the lack of the polyketide synthase gene found in other A. sojae strains. In addition, SMF 127 and SMF 131 were not cyclopiazonic acid (CPA) producers because of the deletion of maoA, dmaT, and pks/nrps, which are involved in CPA biosynthesis. Therefore, A. sojae strains such as SMF 127 and SMF 131, which have high protease and LAP activities and are free of safety issues, can be considered good starters for soybean fermentations, such as in the production of the Korean fermented soybean products meju, doenjang, and ganjang.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.712-719
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• 2018

This study was carried out to obtain basic data on Korean traditional Meju collected from 18 regions (TM1~TM18) in Korea and to define and control quality. The shape of Meju was mostly rectangular and the weight was 0.84~2.04 kg. The physicochemical analysis showed: pH, 5.31~8.21; total acidity, 0.91~2.74%; moisture content, 4.79~42.16%; and soluble protein content, 41.37~23.48%. Hunter color values for L (lightness), a (redness), and b (yellowness) ranged from 39.07~67.92, 3.57~8.87, and 7.48~20.67, respectively. The amino nitrogen contents of all samples were in the range of 257.29 to 839.58 mg% and TM13 showed the highest content (839.58 mg%). Total viable cells, yeast and mold counts of Meju were 8.43~5.91 log CFU/g, 2.48~5.19 log CFU/g, and 3.42~7.48 log CFU/g, respectively. Based on the results, it is proposed that quality standards and management of Meju fermentation conditions and information about different varieties of soybeans used should be made available.

• 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.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.490-495
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• 1999

A thermotolerant yeast Saccharomyces cerevisiae OE-16 was isolated from traditional Meju was investigated on their physiological characteristics and ethanol fermentation ability. Saccharomyces cerevisiae OE-16 were able to grow up to 45$^{\circ}C$ and 40% of glucose. Saccharomyces cerevisiae OE-16 was also resistant to 15% of KCl 1,200ppm of Pb2+, Hg2+ and 500ppm of potassium sorbate. From 20% glucose media Saccharomyces cerevisiae OE-16 produced 83.4g per liter of ethanol at 3$0^{\circ}C$ and 9.5g per liter of ethanol at 4$0^{\circ}C$ for 72 hours.