• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.403-407
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• 1984

The purpose of this study was to investigate the changes of phytic acid content and phytase activity and the interactions between phytic acid and minerals in the preparation of Meju (fermented steamed soybean mash with molds). Meju contained significantly lower phytic acid and higher phytase activity than both raw and cooked soybeans. This seems to be the result of degradation of phytic acid by phytase produced during preparation of Meju by Aspergillus oryzae. Fe, Zn, Ca contents of soybeans were not changed either by cooking or fermentation. However, these minerals in the retentate of ultrafiltration were significantly lower in Meju than in raw and cooked soybeans. This result indicated that there are lower mineral-phytic acid complex in Meju than in raw and cooked soybeans, which might contribute to higher bioavailability of these minerals in Meju.

• Mycobiology
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• v.43 no.3
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• pp.258-265
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• 2015

The fungi on Meju are known to play an important role as degrader of macromolecule of soybeans. In order to elucidate the origin of fungi on traditional Meju, mycobiota of the air both inside and outside traditional Meju fermentation rooms was examined. From 11 samples of air collected from inside and outside of 7 Meju fermentation rooms, 37 genera and 90 species of fungi were identified. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp., Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, Asp. nidulans, Aspergillus sp., Cla. cladosporioides, Eurotium sp., Penicillium sp., Cla. tenuissimum, Asp. niger, Eur. herbariorum, Asp. sydowii, and Eur. repens were collected with high frequency. The concentrations of the genera Aspergillus, Eurotium, and Penicillium were significantly higher in inside air than outside air. From this result and those of previous reports, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, Asp. oryzae, Pen. polonicum, Eur. repens, Pen. solitum, and Eur. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following year. This could explain why concentrations of the genera Aspergillus, Eurotium, and Penicillium are much higher inside than outside of the fermentation rooms.

• Journal of Nutrition and Health
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• v.18 no.2
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• pp.139-146
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• 1985

This study was attempted to investigate the effect of fermentation of soybean on protein and mineral bioavailability. The traditional, oriental fermented soybean foods, Meju and Tempeh, and isolated soybean protein( ISP ) and cooked soybean were prepared and fed to rats as sources of protein. The C-PERs of ISP, cooked soybean, Meju and Tempeh were 1.82, 1.98, 2.11, and 2.36, respectively C-PERs of fermented soybean products, Meju and Tempeh were higher than ISP and cooked soybeans. However, they were not significantly different The percent retention of protein of rats fed with casein, ISP, cooked soybean, Meju and Tempeh were 47.44%, 51.83%, 47.67%, 50.90% and 45.97%, respectively, showing no significant differences among the diets. The rates of calcium retention percent were 62.26%, 59.22%, 61.59%, 55.78% and 67.09 % in rats fed with casein, ISP, cooked soybean, Meju and Tempeh, respectively, demonstrating no significant differences. Rats fed with cooked soybeans did show significantly higher iron retention rate than other samples. However, this study failed to any significant increase in iron availability. The percent of fine retained in rats fed with ISP was significantly lower than those of rats fed with other diets, however, significantly high amounts of zinc were retained in rats fed with Tempeh compared with other diets. The percents of zinc, iron, calcium retained in the bones of rats were not significantly different among the diets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.3
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• pp.189-195
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• 1983

Changes of lipid composition in the Improvement-Meju inoculated with Aspergillus oryzae were examined. To investigate those changes systematically, silicic acid column chromatography was used for analysis of glycolipid, neutral lipid, phospholipid, and gas chromatography to examine the change of those fatty acid content. Following results were obtained. The lipid fraction obtained from soaked soybean and cooked soybean were mainly composed of about 93~94% neutral lipid, whereas phospholipid and glycolipid was 4.0~5.0%, 2.0~2.1% level, respectively. During meju incuvation period, neutral lipid decreased gradually, but glycolipid and phospholipid increased. Among the nonpolar lipids prepared from cooked soybean and soaked soybean, triglyceride content was mainly composed of 88~89%, and the content of sterol ester, free fatty acid, diglyceride and sterol was higher in soaked soybean than in cooked soybean. During meju incuvation period, triglyceride content decreased remarkablely, whereas content of sterol ester, free fatty acid and diglyceride increased gradually. From the soaked soybean and the cooked soybean, the fatty acids content of crude lipid, neutral lipid, glycolipid and phospholipid were composed of linoleic acid 54~70%, oleic acid 20.0~22.6%, palmitic acid 11.0~12.4%, linolenic acid 6.0~7.8% and stearic acid 3.4~4.3% in turn and myristic acid showed the trace, palmitic acid was a little higher in glycolipid and phospholipid than in crude lipid and neutral lipid. During meju incuvation period, the change of fatty acid content showed linoleic acid and linolenic acid reduction gradually in the neutral lipid, glycolipid and phospholipid. On the other hand, palmitic acid, stearic acid and oleic acid increased gradually, the maximum value was at the 4-days. The change of glycolipid fatty acid and phospholipid fatty acid was examined. 9-kinds including traced 3-kinds was detected. It was supposed that traced 2-kinks was occurred for incuvation, and those are the matter investigating in the future.

• Food Science and Preservation
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• v.9 no.3
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• pp.315-320
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• 2002

In order to improve some problems such as contamination of undesirable mold, mycotoxin production and excessive drying on the surface of traditional meju. Control meju without koji and capsule type meju(CM) coated with soybean mixture containing 0.5%, 1% and 2%(w/w) R. oligosporus koji were dried at room temperature (10∼15$^{\circ}C$) for 3 days. Control meju I was fermented in outdoor for 27 days. Control meju IIand CMs were fermented in Korean yellow clay room at 25$^{\circ}C$ for 7 days under 80% relative humidity as first step, and then fermented in outdoor (average temp. 2.7$^{\circ}C$, December) for 20 days as second step. The moisture content of CMs were higher than that of control meju I to the range of 2.88∼7.55%(w/w). pH and titratable acidity in CMs were similar to control group. Amino type nitrogen content in CMs(800.80, 816.0, 901.60 mg%) were 2.2∼2.6 times higher than that in control meju I (347.2 mg%). Reducing sugar content in CMs(2.78∼3.13%) was similar to control meiu I (2.10%) and control meju H(2.31%). Lightness(L) value of control meju I was higher than that of control meju IIand CMs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.13-20
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• 1991

For this experiment frist the fermented Soybean Meju was prepared by domestic ordinary method of Korean and concentrated Meju suspensoidal extract was made for toxicological test sample on mice and rat. Even the oral dose of 10g extract per kg of mice had not any acute toxicity. So the median lethal dose(LOD50) is lilely to be much greatr or not to be. In comparison of the average weight gain rate for 4 weeks the control and test groups of 0.308g Ex/rat kg and 9.24g Ex/rat kg daily were the much the same as about 19% but 3.08g Ex/rat kg group waas exceptionally 2.7% higher than control For this period all test groups did not show any abnormality in appearance and anatomic findings. In serum GPT GOT alkaline phosphatase and blood urea nitrogen value there were no difference significantly between control and the test groups of 0.308g/rat kg and 3.08g/rat kg but 9.24g/rat kg group was some what higher than control. Especially in cholesterol alkaline phosphatase and blood urea nitrogen value 9.24g/rat kg group or 28days had 100mg/이 37.5u 32mg/이 respectively which were increased significantly. The pathological findings of all test groups especially 9.24g/kg group did not showed any characterized sign of acute or subacute liver damage or intestine lesion. So it is supposed that there is not any tocixants originated from some molds in fermented Korean domestic Meju which is prepared traditionally in winter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.259-267
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• 1998

Typical characteristics of Mejus must be understood to get the basic data for setting up mass production system of traditional fermented soybean products. One hundred and twenty one Mejus were collected from various places and analyed. Most of shapes were rectangular and some were spherical, conical, cylindrical and doughnut types. The weight of Mejus was 0.4~4.2kg. Chemical analysis showed: moisture content, 9.73~58.22% ; pH, 4.95~8.15; acidity, 0.6~3.8% ; soluble protein content, 4.45~12.31%; soluble sugar content, 0.82~10.95%. Enzyme assay showed: $\alpha$-amylase activity, 5.0~874.2 units/g; $\beta$-amylase activity, 0.02~27.74units/g; acidic protease activity, 31.3~225.1unts/g; lipase activity 1.0~53.0units/g. Total viable cells were 3.72$\times$107~1.35$\times$1010cfu/g, and yeast and mold count 6.46$\times$104~8.91$\times$106cfu/g. respectively. $\alpha$-Amylase activity of a traditional Meju from Incheon showed the highest activity of 732.8 units/g(interior section) and 823.2units/g (exterior section). $\beta$-Amylase activity was the highest{3.57 units/g (interior sectin) and 4.25units/g (exterior section)} in Meju from Chunbuk. Acidic protease activity was the highest in sample from Seoul, whereas traditional Meju from Kyongnam showed the highest activity of 21.5units/g(interior section) and 37.5units/g(exterior sectin).

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.188-196
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• 1995

To obtain useful mould strain in soybean fermentation industry, we collected conventional Meju all over the Korea and tested existance of aflatoxin in Meju collected. Also, we measured distribution of microorganism and enzyme activity of Meju and isolated Aspergillus oryzae O4-5 as a industrially useful mould. The results obtained were summarized as follows: 1. Aflatoxin was not detected by EZ-Screen Test Kit and HPLC analysis in various Meju sample collected all over the Korea from 1994.12 to 1995.2. 2. Colony forming units(CFU) of mould, yeasts, aerobe, and anaerobe were $1.3{\times}10^4-2.8{\times}10^6$, $1{\times}10^2-1.5{\times}0^6$, $2.0{\times}10^7-8.0{\times}10^8$ and $3.0{\times}10^6-7.3{\times}10^8$ per gram of Meju, respectively, indicating that CFU inter Meju samples were varied with big difference. 3. The activities of ${\alpha}$-amylase and gluco-amylase were 5-80 units and 2-34 units per g of Meju, respectively. It was shown that enzyme activity was varied depending on where the Meju was collected. 4. The activities of acidic, neutral and alkaline protease were 5-33 units, 5-302 units and 5-363 units per g of Meju, respectively. Acidic protease of Improved Meju made by D-Company was higher than that of conventional Meju as 66 units per g of Meju. 5. CNU O4-5 strain selected as a noble strain could produce amylase and protease in high level, and identified as a strain that belongs to Aspergillus oryzae. 6. The activities of acidic and neutral protease of Aspergillus oryzae CNU O4-5 strain isolated were about 10% higher than those of Aspergillus oryzae JM which has been used in soybean fermentation industry. Amylase activity of CNU O4-5 strain was similar to Aspergillus oryzae JM.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.89-98
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• 2003

To assess the actual status of businesses selling fermented soybean products, this study surveyed 130 Farmhouse style small size soybean sauce processing sites supported by the Rural Development Administration nationwide. The sex composition of the businesses representatives of 2% male and 98% female showed that a farmhouse soybean processing business is generally operated by rural women as a non-filming business. The percentage of co-worked sites was 71.2 and that of sites with permits was 39.2. The main products were meju, doenjang, and kanjang. Total production volume was found to be 523 tons, 256 tons, and 135 k$\ell$s, respectively. The number of years of experience of the manufacturers of the kanjang and doenjang was found to be 25.7 on average which shows that long-experienced, skilled manufacturers are participating in this project. The traditional measuring unit differed greatly depending on the region. This difference in the measuring unit of soybeans resulted in a large difference in the volume of doenjang and kanjang produced Per Province. For one kg of raw soybeans, the weight of Doenjang produced also varied from 2.14 kg in the Gyeongbuk area to 1.62 kg in Jeju. In the aspect of salt use, 1.75 $\ell$ (translated by volumetric unit 0.704 due) of salt pet kg of meju, in Jeju, was the highest in Korea. Government supervision would be beneficial in the areas of raw material products, standardization of measuring units and production methods, organization and operation of a conference for the different groups of producers, and in construction of a nationwide database.

• Food Science and Preservation
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• v.20 no.2
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• pp.191-198
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• 2013

In this study, wheat doenjang was manufactured using Korean wheat meju and soybean meju, and its quality were investigated according to mixing ratio of meju. The general characteristics such as moisture contents, pH and salinity of wheat doenjang, which is fermented and aged at $25^{\circ}C$ for 70 days, were slightly decreased time dependently as similar pattern. The pH of wheat doenjang ranged from 4.95 to 5.11% and generally decreased with aging. The moisture contents was 54.5~57.5%, and there was no significant differences in the aging period. Also, there was no significant changes in the salt contents. The amino-type nitrogen contents were 376.27~600.91 mg% at day 70 of the aging period, and showed 3 fold change compared to the initial contents. The reducing sugar contents showed significant difference between the samples, and repeated fluctuation in the aging period. Wheat meju sample A, which contains 50% of soybean meju, showed the highest antioxidation ability. In addition, wheat meju sample A showed the highest score in the sensory evaluation of the colour, taste, flavor, and overall acceptability. Therefore, wheat doenjang manufacturing at a 1:1 of mixing ratio will lead to desirable quality of wheat doenjang.