• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.609-615
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• 1994

Fermented traditional soybean paste(doenjang), koji soybean paste by Aspergillus oryzae, natto soybean paste by Bacillus natto and koji & natto soybean paste by Aspergillus oryzae and Bacillus natto were analyzed for compositions of amino acids and contents of nitrogens. Amino type nitrogen was the highest in fermenting for 90 days as $271{\sim}868\;mg/100g$, and its contents were in the order of koji soybean paste>traditional soybean paste>koji & natto soybean paste>natto soybean paste in all samples tested. In compositions of total amino acids, glutamic and aspartic acids were rich in koji soybean paste but big differences were not observed in all samples. But some differences were observed in free amino acid compositions in all samples, that is, glutamic acid, tyrosine, lysine and aspartic acid were detected more abundantly. Sum of free amino acids for 90 days were in order of koji soybean paste>traditional soybean paste>koji & natto soybean paste>natto soybean paste. The ratios of free to total amino acids were $3.28{\sim}19.81%$ for 45 days, but increased to $10.88{\sim}25.10%$ for 90 days, and in order of traditional doenjang>koji doenjang>koji & natto doenjang>natto doenjang. Methionine and histidine showed higher ratios of free to total amino acid but lower in glutamic acid and aspartic acid. These results suggest that koji and traditional soybean paste of having high ratios of free amino acids to free and total amino acids may be more favorable in soybean paste fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.917-924
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• 1995

Four types of soybean paste(Doenjang), prepared with traditional Korean meju, natto meju, koji and mixture of koji and natto meju, were analyzed for compositions of free sugars and fatty acids. Crude protein content of the soybean pastes were ranged from 10.3~14.6% and in the order of traditional Korean soybena paste>natto soybena paste>koji & natto soybean paste>koji soybean paste during fermentation of Doenjang. Ethyl alcohol contnet was relatively higher in koji and natto soybean paste after fermentation for 75 days, and its content was the highest in koji soybean paste as 2.8% after fermenting for 90 days. Contents of total sugars and reducing sugars decreased during fermentation of doenjang in the order of koji soybena paste>koji and natto soybean paste>traditional soybean paste>natto soybean paste. Among the free sugars glucose, galactose, mannose and arabinose were identified in soybean paste, and glucose and galactose were more bundant. Contents of glucose and total free sugars were the highest in the traditional Korean soybean paste and galactose content was highest in koji soybean paste. In fatty acid compositions of soybean pastes, palmitic, stearic, oleic, linoleic, linolenic and arachidonic acids were analyzed, and the most abundant fatty acid was found to be oleic acid as 38.5~46.9% in all samples tested. But no significant differences in ratio of fatty acid compositions was observed from tested samples during the fermentation period.

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.314-322
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• 2010

The effects of five colored soybean (blue, red, yellow, white, and black) varieties on the quality characteristics of soybean paste (Doenjang) were investigated for proximate composition, salt content, pH, color, organic acid content, amino acid content, and mineral content after 80 days of aging. Soybean paste (Doenjang) samples were divided into TDS (traditional Doenjang prepared with soybean) and TDM (traditional Doenjang prepared with mixed soybeans, kidney bean, black soybean, kind of small bean, sword bean, green bean, red bean, at a radio of 1:1:1:1:1(w/w)). Moisture content was 49.66% for TDM and 49.52% for TDM. Protein and salt contents of the TDS sample were higher than those of TDM. The "L" values of the TDB sample increased the aging period was decreased. In contrast, the "L" and "$\alpha$" values of TDM did not show any significant differences. The main organic acids detected were malic acid > lactic acid > tartaric acid in the TDS and TDM samples. Glutamic acid contents were 2.83 g/100 g for the TDS sample and 2.15 g/100 g for the TDM. The levels of K, Mg, and Ca of the TDS sample were higher than those of TDM. No significant difference occurred between TDS and TDM regarding their quality characteristics after 80 days of aging. Further studies needed include sensory evaluation and functionality of soybean paste made from mixed soybean materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.305-311
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• 1999

The volatile compounds of soybean pastes(home made soondoenjang, commercial doenjang) were classified into basic, acidic and neutral fractions by dynamic headspace method. The fractionated flavor isolates were analyzed and identified by gas chromatography mass spectrometry. Each peak area of the flavor components was quantified at its ratio to the peak area of internal standard. Sixty one compounds from home made soondoenjang, and forty three compounds from commercial doenjang were identified. The different distribution of volatile compounds between the two soybean paste samples was observed. Ten pyrazines and benzothiazole were identified in the basic fraction of home made soondoenjang. On the other hand, trimethylpyrazine was the only one of nitrogen containing compounds in the commercial doenjang, which was made from soybean(28.3%), wheat(22.2%) and alcohols. The factors which influenced the levels of these identified compounds were considered to be the starting materials of soybean paste. Alcohols, esters and aldehydes in the neutral fraction of both samples were seemed to be characterisitic soybean paste flavor and showed much higher quantities than those of the basic or acidic fractions. Furfural in the commercial doenjang was the highest content (45.28ppm) among all of the compounds identified in the samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.376-382
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• 1997

Antioxidative characteristics of doenjang(fermented soybeans paste) phenolics on the lipid oxidation systems were studied by the determination of the oxidative related activity including lipoxygenase (LOX) inhibition, metal chelating and free radical scavengning of doenjang phenolics. Manlikong variety containing the highest amounts of phenolic compounds among the soybean variety, was used for doenjang processing. Doenjang was prepared by the series of processes including soaking for overnight, cooking for 1hr at 12Lb, first fermentation (3 days at 30$\pm$2$^{\circ}C$) for the preparation of meju(soybean koji) after inoculation of Asp. oryzae, and further fermentation(60 days at 30$\pm$2$^{\circ}C$) for the ripening after addition of salt 13% to meju. In order to investigate the antioxidative activity of phenolics in doenjang, the doenjang phenolics was extracted with methanol form freeze dried defatted doenjang. Antioxidative effects of methanol extract on linoleic acid oxidation system were observed by the significantly decreased levels of peroxide and conjugated diene formation. In addition, methanol extract resulted in the inhibition of LOX activity. and also, metal(FeCl$_3$) chelation and free radical scavengning activities were increased with increasing concentration of methanol extract.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.13-14
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• 2001

Doenjang (Korean fermented soybean paste) is one of important fermented foods in Korea. Doenjang has been traditionally manufactured from meju which is fermented rectangular shape of crushed cooked soybeans. The main microorganisms involved for meju fermentation are Bacillus subtilis and molds such as Rizopus sp., Mucor sp. and Aspergillus sp. We have already reported that Doenjang is free from mycotoxin, especially, aflatoxin B$_1$contamination during the manufacturing process of the Deonjang.(omitted)

• Journal of Radiation Industry
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• v.10 no.1
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• pp.13-20
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• 2016

In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine>Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.980-985
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• 1994

We investigated the quality of soybean paste(Doenjang) fermented by BAcillus brevis. The results obtained were as follows : soybean paste fermented by Bacillus brevis had alkaline pH and yellow ochre color. Dextrinizing activity was about 98 D.P. unit from 5th to 25th day of fermentation at 3$0^{\circ}C$ and after that day somewhat decreased . Saccharifying activity was respectively 6.1, 7.2, 6.8, 6.4 S.P. unit on 5, 15, 25 and 35th day of fermentation. Protease activity suddenly increased after 15th day of fermentation and was 250, 275, 299 unit on15, 25, 35 th day of fermentation , respectively. The most abundant free amino acid was found to be glutamic acid (561.8mg%) in soybean paste fermented by Bacillus brevis. In case of free sugar and non-volatile organic acid, fructose and oxalic acid showed highest content of 10.25mg% on 25th day and 12.20mg% on 15th day. The contents of free amino acids, free sugars, organic acids in soybean paste fermented by B.brevis were most abundant after 25 days of fermentation and this results were similar to that of traditional soybean paste. The odor of soybean paste fermented by Bacillus brevis was improved to be a nice soybean paste odor on 25th day of fermentation. However, sensory evaluation value of the taste of it decreased after 10 th day of fermentation.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1030-1034
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• 2009

A fermenting microorganism involved in formation of ortho-dihydroxyisoflavones (ODIs) during aging of doenjang (Korean fermented soybean paste) has been investigated. Microorganisms in ODI-containing doenjang were isolated by cultivating on yeast mold (YM) agar medium containing 0-7% NaCl. ODI formation of the isolated strains was examined by gas chromatography/mass spectrometry (GC/MS) analysis after cultivation in modified YM broth or soybean extract medium. An ODI-producing microbe was identified as Bacillus subtilis HS-1 based on 16S rRNA gene sequence analysis. The strain has produced 8-hydroxydaidzein as a major product during growth in the modified YM broth or soybean extract medium. Therefore, it was concluded that one of the microorganisms involved in the formation of ODIs in doenjang was B. subtilis HS-1.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.255-260
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• 1994

Four types of soybean paste(Doenjang), using traditional meju, koji, natto meju and mixture of koji and natto meju, were manufactured and fermented for 90 days. Analyzed volatile flavor components by GC-MS were confirmed to be thirty-six components including 5 alcohols, 5 aldehydes. 8 ketones, 3 acids, 9 esters and 6 miscellaneous ones. Traditional soybean paste tested had 29 components, koji and koji-natto soybean paste $26{\sim}24$ and natto soybean paste had 20 ones. Alcohol was found to be the most abundant volatile flavor components in all samples group. Traditional soybean paste had higher ratio of carbonyl to ester than any other types of soybean paste while koji-natto soybean paste had the lowest ratio of their components. The newly identified five volatile flavor components were 3-ethoxy-l-propene, dihydro-2-methyl-3-furanone. 1-hydroxy-2-propanone, 1-(2-furanyl)ethanone and 2-acethyl ethylhexanoate.