• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1952-1960
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• 2017

Recently, soybean isoflavone aglycones (i.e., daidzein and genistein) and ${\gamma}-aminobutyric$ acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides (i.e., daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. Lactobacillus brevis GABA 100 and Aspergillus oryzae KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and $59{\mu}g/g$, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell L. brevis GABA 100 and A. oryzae KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.828-831
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• 2005

The content of vitamin $D_2$, including its precursor ergosterol, was determined in some cultivated mushrooms to manufacture fortified Doenjang (Korean traditional soybean paste) with vitamin D by supplementation with mushroom. Ergosterol was the most abundant sterol in the mushrooms (50 to 140 mg/100 g dry weight) but the ergocalciferol portion made up only 0.065% (Pleurotus eryngii) to 2.5% (stipe part of Lentinus edodes, shiitake) of the total vitamin $D_2$ of each mushroom. Changes in these compounds in L. edodes caused by UV or solar irradiation were also evaluated. Ergocalciferol content in the pileus part of L. edodes went up to $424\;{\mu}g/100\;g$ dry weight and ergosterol levels reached 139.3 mg per 100 g dry weight at maximum levels. Ergocalciferol content increased about 50% when exposed to solar radiation and increased 377% with UV irradiation. These compounds level in Doenjang was enriched as much as supplied UV irradiated L. edodes powder to before fermentation, and the supplemented mushroom did not influence the palatability of Doenjang.

• Korean Journal of Food Science and Technology
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• v.9 no.1
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• pp.73-80
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• 1977

In order to detect the occurrence of aflatoxins in some suspecious Korean foodstuffs, 54 samples of Meju (a naturally inoculated soybean substrate for soy sauce and paste fermentation), 125 samples of Doenjang (a Korean-style fermented soybean paste), both produced at household level, and 31 samples of peanut were collected from 8 major cities of South Korea and subjected to assay by the official method of AOAC. The results were as follows: 1) Frequencies for the occurrence of aflatoxins in Meju, Doenjang and peanut were 7.4%(4/54), 8.8%(11/125) and none (0/31), respectively, in which Meju and Doenjang samples from Daegu and Busan showed the high ratio of the presence. 2) A Doenjang sample from Busan was found to contain the highest content of aflatoxins, of which $B_1,\;B_2,\;G_1\;and\;G_2$ were 66 ppb, 13 ppb, non-detectable and 5 ppb, respectively, while other samples detected were for $G_2$ only. 3) The identity of aflatoxin $B_1$ isolated from the Doenjang sample from Busan was confirmed by thin-layer chromatographic behavior, derivative formation and chicken embryo bioassay.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.87-94
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• 2007

A bacterium which has high enzymatic activities such as amylase, cellulase and protease was isolated from Korean traditional soybean food, doenjang. The isolated bacterium was identified to Bacillus subtilis HS25 by the test of morphological and biochemical properties according to Bergey's Manual of Systematic Bacteriology and API 50 CHL kit, and by the 16S rDNA sequence. The isolated B. subtilis HS25 had a potent antibacterial activity against food born causative or pathogenic bacteria. B. subtilis HS25 is endospore forming cell and contained flagella and abundant viscous material at the out layer of cell wall. It was rod type bacterium $(0.5{\sim}0.8{\times}3{\sim}5{\mu}m)$ having biochemical characteristics such as gram staining(+), catalase(+), oxidase(-) and hydrolysis of esculin(+). The optimal medium compositions for production of antibacterial substance in the B. subtilis HS25 were 1% of soluble starch, 0.5% of yeast extract, 0.5% of peptone and 0.05% of MgCl$_2{\cdot}6H_{2}O$. The optimum temperature and pH of the growth of the B. subtilis HS25 was 35$^{\circ}C$ and pH 7.5, respectively. The antibacterial activity was more high in neutral to a little alkaline pH (6.5-10.5) than in acidic pH. The optimal shaking speed to grow and to produce antibacterial substance of the B. subtilis HS25 was 160${\sim}$200 rpm. The optimal culture time for antibacterial activities of the bacterium were shown to be in the range of 12-36 hr.

• Food Science and Preservation
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• v.19 no.2
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• pp.278-286
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• 2012

The growth inhibition effect of $Doenjang$ that was prepared with various kinds of solar salt was investigated. $Doenjang$ was prepared using the bacterial koji and five kind of salt with 12% salt concentration (w/w): purified salt $Doenjang$, one-year aged solar salt $Doenjang$, four-year aged solar salt $Doenjang$, topan solar salt $Doenjang$, and boiled solar salt $Doenjang$. The $Doenjangs$ were fermented and aged for 18 months. The growth inhibition effects of the water extracts and the methanol extracts of the $Doenjangs$ were measured on AGS human gastric adenocarcinoma cells, HT-29 colon carcinoma cells, and BJ human foreskin normal cells using MTT assay. The water and methanol extracts of the $Doenjang$ samples showed growth inhibition effects on the cancer cells, in the following order of the samples with the strongest to the weakest effect: the four-year aged solar salt $Doenjang$, the topan solar salt $Doenjang$, the boiled solar salt $Doenjang$, the one-year aged solar salt $Doenjang$, and the purified salt $Doenjang$. The methanol extracts of the four-year aged solar salt Doenjang (AGS: 55% and HT-29: 48%) showed the strongest growth inhibition effect. In addition, decreased cancer cell numbers and morphological changes in the cancer cells (AGS and HT-29) were observed when the methanol extract of the four-year aged solar salt $Doenjang$ was treated. None of the $Doenjang$ extracts showed a growth inhibition effect on the BJ normal cells, though.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.360-366
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• 2010

Doenjang (fermented soybean paste) is one of the korean traditional fermented soybean product which is consumed with cooked rice as a soup or paste. During the fermentation, soybean protein hydrolyzed into amino acids and various peptide, and various organic acids by mirobes related and enzymes produced by meju fermentation. Some commercial products locationally samples give more sour taste than normal due to abnormal fermentation which the reasons are not clear. Three samples that gave sour taste organoleptically were collected and analyzed their characteristics such as pH, moisture content, acidity and microbial counts. The pH of the sour sample were lower than the normal with higher acidity as pH 5.39 (normal) to pH 4.36 (S2) and 15.80 ml of(0.lN NaOH consumed) to 21.80 ml (S1) respectively. Salt and moisture contents were different with sour and normal Doenjang as 16.38% (normal) to 8.92% (S3) in salt and 55.94% (normal) to 49.34% (S1) in moisture content. Total viable counts were $4.1{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2), and $3.4{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2) in acid producing microbes at BCP plate. Yeast and mold were not detected. The composition of acids as mainly lactic acid and acetic acid of sour Doenjang. Total free amino acids content were lower the sour Doenjang than the normal.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.234-241
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• 2007

A physicochemical assessment of Doenjang (traditional fermented soyfood) prepared with Korean black soybeans (Glycine max) was carried out. The T-N rate increased slowly during storage up to 120 days and the A-N rate increased up to 80 days of ripening and then decreased slightly. The caseinolytic activity increased slowly during storage up to 80 days and then decreased after 80 days. In addition, the fibrinolytic and ${\beta}-glucosidase$ activities increased up to 80 and 30 days and then decreased. Genistin and daidzin concentrations gradually decreased with increased fermentation time. However, genistein and daidzein slowly increased with fermentation time. Genistein and daidzein reached maximum concentrations (316.8 and $305.2{\mu}g/g$, respectively) and plateaued thereafter. The anthocyanins increased greatly during fermentation up to 50 days and then remained constant between 50 and 90 days. Polyphenol contents showed a slight increase up to 80 days and then slowly decreased. The DPPH and ABTS radical scavenging activities increased linearly during storage up to 50 days, reached about 28.9% and 2.17 mg/g, respectively, and then slowly decreased. At 20 days of fermentation, macrophage-stimulating activity of the extract showed a maximum activity.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.45-50
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• 1994

Conventional Doenjang, three kinds of Improved Doenjang(A; koji: soybean: salt=53: 100: 33, B; koji: soybean: salt=100: 100: 40, C; koji: soybean: salt= 200: 100: 40) prepared with different ratio of koji and salt were made to study the changes in the general contents, characteristics bitter peptides, correlations between bitterness and overall eating quality. 1. Total nitrogen contents increased a little, and amino nitrogen contents in all samples increase markedly. Especially, Amino nitrogen contents of conventrional Doenjang increased more than others. Reducing sugars of doenjang prepared with Asp. oryzae were higher than conventional Doenjang and increased throughout the aging period and Doenjang prepared with Asp. oryzae were more acidic. 2. To characterize bitter peptides in fermented Doenjang, peptides were extracted with 2: 1(v/v) chloroform-methanol and separated by Gel chromato-graphy with Sephadex and TLC. After Gel chromatography and TLC, each fraction examined presence of bitterness and evaluated intensity of bitterness. Amino acid composition of the fractions showing bitter tastes were as follows. Conv. peak 1-1 Trp-(Asp, Arg, Thr, Ser, Glu, Pro)-Phe Imp. A peak 1 Trp-(Glu, Val, Arg, lie)-Phe Imp. B peak 1 Trp-(lie, Pro, Asp, Lys, Val, Glu)-Trp. Imp. C peak 1-2 Trp-(Try, Thr, Glu, Pro, Gly)-Phe 3. Sensory evaluation revealed that correlation coefficient between bitterness and overall eating guality was not high.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.99-109
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• 2003

This study was conducted to collect basic marketing and management data from businesses run by farmers producing traditional Kanjang and Doenjang, fermented soybean products. The actual conditions of the fermentation processing sites at farmhouses participating in the production of soybean fermentation products were investigated. The subjects of this survey were 130 small size farmhouse Kanjang and Doenjang processing sites nationwide. The frequency, percentage, t-value, chi-square, and ANOVA were used for statistical analysis. The farmhouse business surveyed were generally operated by rural women for non-farming business income. The percentage of co-worked sites was 71.2 while the percentage of sites operating with permits was 39.2. Generally, the the facilities, size, number of working people, and output were very small. The areas in which the products were sold, site-located regions and region metropolises, were equally weighted. Sales volumes in region metropolises for sites with permits were a little higher than sites without permits. Without regard to operation type, the percentage of sales was highest in cases of direct sale by customer order. Co-worked sites have been found to have more experience in publicity than individually operated sites. As for methods of publicity, co-worked sites use mass media such as newspapers and broadcasting. Individually operated sites usually use social organizations and acquaintances. It was found that the average sales of each site totaled 25 million Won. The average income of each site was 12 million Won, and average income per participant was 3 million Won. Total sales income for sites with permits was significantly higher than sites without permits. But personal income was much higher at individually operated sites without regard to whether the site had a permit or not. This kind of business was found to contribute to an individual's time management skills as well as instill a sense of pride.