• Nutrition Research and Practice
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• v.9 no.6
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• pp.569-578
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• 2015

BACKGROUND/OBJECTIVES: Fermentation can increase functional compounds in fermented soybean products, thereby improving antioxidant and/or anti-inflammatory activities. We investigated the changes in the contents of phenolics and isoflavones, antioxidant activity and anti-inflammatory activity of Doenjang during fermentation and aging. MATERIALS/METHODS: Doenjang was made by inoculating Aspergillus oryzae and Bacillus licheniformis in soybeans, fermenting and aging for 1, 3, 6, 8, and 12 months (D1, D3, D6, D8, and D12). Doenjang was extracted using ethanol, and sequentially fractioned by hexane, dichloromethane (DM), ethylacetate (EA), n-butanol, and water. The contents of total phenolics, flavonoids and isoflavones, 2,2-diphenyl-1 picryl hydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) were measured. Anti-inflammatory effects in terms of nitric oxide (NO), prostaglandin (PG) E2 and pro-inflammatory cytokine production and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions were also measured using LPS-treated RAW 264.7 macrophages. RESULTS: Total phenolic and flavonoid contents showed a gradual increase during fermentation and 6 months of aging and were sustained thereafter. DPPH radical scavenging activity and FRAP were increased by fermentation. FRAP was further increased by aging, but DPPH radical scavenging activity was not. Total isoflavone and glycoside contents decreased during fermentation and the aging process, while aglycone content and its proportion increased up to 3 or 6 months of aging and then showed a slow decrease. DM and EA fractions of Doenjang showed much higher total phenolic and flavonoid contents, and DPPH radical scavenging activity than the others. At $100{\mu}g/mL$, DM and EA fractions of D12 showed strongly suppressed NO production to 55.6% and 52.5% of control, respectively, and PGE2 production to 25.0% and 28.3% of control with inhibition of iNOS or COX-2 protein expression in macrophages. CONCLUSIONS: Twelve month-aged Doenjang has potent antioxidant and anti-inflammatory activities with high levels of phenolics and isoflavone aglycones, and can be used as a beneficial food for human health.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.138-143
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• 2005

Antibacterial, free radical scavenging, proliferative, and cytotoxicity effects of Doenjang extracts were examined. All samples except water extract showed strong antibacterial activity against oral bacteria, Streptococcus. pyogenes, S. mutants, S. sanguinis, S. sorbrinus, S. criceti, S. antinosus, S. gordonii, and Porphyromonas. gingivalis (MIC and MBC values: 0.08-1.25 and 0.16-2.50 mg/ml, respectively). DPPH method showed ethanol and ethyl acetate extracts are effective inhibitors of oral bacteria. Based on MTT assay, 24 h exposure to 0.31 mg/ml of all extracts, excepted water extract, resulted in strong cytotoxicity on KB cells. All extracts strongly inhibited human gingival fibroblast viability.

• KSBB Journal
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• v.27 no.6
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• pp.361-366
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• 2012

We investigated the anti-diabetic activity and enzymatic activity of 24 commercial doenjang samples certified for traditional foods. Twenty four doenjang samples showed the wide ranges in enzymatic activities (protease activities 0-50.45 unit/g, ${\alpha}$-amylase activities 0-675.9 unit/g, ${\beta}$-amylase 13.6-308.6 unit/g), and there were no difference in enzymatic activity by the producing region. To evaluate the potential anti-diabetic activity of 24 doenjang samples, we examined the effect of doenjang methanol extract (DME) on 2-[n-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amyno]-2-deoxy-d-glucose (2-NBDG) uptake. Ten samples among 24 samples significantly stimulated the uptake of 2-NBDG. When the cells were treated with DME at 400 ug/mL, No. 17 and 23 specially stimulated 2-NBDG uptake by 1.23-fold and 1.25-fold, respectively, compared with untreated control cell. And there were no cytotoxicity in the C2C12 cells treated with DME at concentration of 500 ug/mL. Among 24 samples, No. 6, 7, 12, 21 and 24 showed the ${\alpha}$-glucosidase inhibitor activity at concentration of 10 mg/mL; however, they were less effective than acarbose which is a commercial ${\alpha}$-glucosidase inhibitor.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1119-1123
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• 2005

The inhibitory effects of water and methanol extracts of Doenjang, Chungkookjang and Miso on bovine hyaluronidase were examined. The extracts were vacuum-dried and the resulting pellets were dissolved with 0.1 M acetate buffer with 1$\%$ DMSO to a final concentration of 50 mg/mL. The water extracts of Doenjang, Chungkookjang and Miso inhibited 62$\%$, 70$\% $, 56$\%$ of hyaluronidase activity, respectively, while the extract of crushed soybean inhibited 24$\%$ of the activity. Under the same condition, disodiumcromoglycate known as an anti-allergic drug inhibited 46$\%$ of hyaluronidase activity at the concentration of 0.35 mg/mL as a positive control. Also the methanol extracts of Doenjang, Chungkookjang and Miso inhibited 48$\%$, 52$\%$, 70$\%$ of hvaluronidase activity, respectively, while the extract of crushed soybean inhibited 46$\%$ of the activity. After heat treatment of the water extracts of Doenjang, Chungkookjang and Miso at 100"C for 10 min, hyaluronidase inhibitory effects of them were reduced approximately to half. However, hyaluronidase inhibitory effects of methanol extracts were maintained well even after heat treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.936-940
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• 2004

Doenjang (Korean soy paste) is one of the popular soybean based fermented foods in Korea. This study investigated the growth and DNA synthesis inhibitory effect of doenjang methanol extracts on AGS human gastric adenocarcinoma cells, Hep 3B human hepatocellular carcinoma cells and HT-29 human colon cancer cells. In order to determine an anticancer effect of doenjang methanol extracts, other soybean fermented foods and original materials were compared. The treatment of doenjang methanol extracts (200 $\mu\textrm{g}$/mL) to the AGS, Hep 3B and HT-29 cancer cells inhibited the growth of cancer cells by 80%, 77% and 86%, respectively. Compared to other soybean fermented foods and original materials, doenjang methanol extracts showed the highest growth inhibitory effect on different cancer cells. In addition, doenjang methanol extracts (200 $\mu\textrm{g}$/mL) significantly inhibited DNA synthesis of AGS and Hep 3B cancer cells by 76% and 59%, respectively. These results suggested that this anticancer effect of doenjang may be due to specific active compounds, which will be newly produced during soybean fermented process and not contained in soybean.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.685-691
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• 2005

Growth and DNA synthesis inhibitory effects of doenjang methanol extract and its solvent fractions on AGS human gastric adenocarcinoma cells, Hep 3B human hepatocellular carcinoma cells, HT-29 human colon cancer cells and MG-63 human osteosarcoma cells were studied. The treatment of doenjang methanol extract ($ 200{\mu}g/ml $) with the AGS, Hep 3B, HT-29 and MG-63 cancer cells after 6 days of incubation inhibited the growth of cancer cells by $32\%$, $51\%$, $84\%$ and $33\%$, respectively. To separate active compounds of doenjang, doenjang methanol extract was fractionated with dichloromethane, ethylacetate, and buthanol. Among the solvent fractions, the dichloromethane and ethylacetate fractions showed the highest growth inhibitory effects on various cancer cells. For example, the dichloromethane and ethylacetate fractions ($200a{\mu}g/ml$) sig-nificantly inhibited the growth of various cancer cells by $89\∼96\%$ and$62\∼86\%$, respectively. DNA synthesis of AGS and Hep 3B cancer cells was significantly inhibited by adding dichloromethane fraction ($200{\mu}g/ml$) up to $94\%$ and $80\%$, respectively. Similarly, the ethylacetate fraction ($ 200\mug/ml $) showed a $ 95\% $ inhibition rate of DNA synthesis in AGS cells. These results suggest that the dichloromethane and ethylacetate fractions have specific active compounds, which will explain this anticancer effect of doenjang.

• Journal of Life Science
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• v.8 no.5
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• pp.473-478
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• 1998

The radical scavenging activity of the methanol extracts was in the order of doenjang〉 meju〉 soybean. The metha-nol extracts were further fractionated with dichloromethane, ethyl acetate, butanol and water in sequence. Among the solvent fractions of the methanol extracts, the ethyl acetate fraction demonstrated high levels of radical scave-nging activity. On the other hands, the nitrite scavenging activity of the methanol extrats was in the order of doen-jang〉soybean〉meju. All fractions from doenjang were exhibited the strong nitrite scavenging effect. Especially, $H_2O$, EtOAc and BuOH fractions with 6gmg/10$m\ell$ concentration exhibited much stronger nitrite scavenging effect than that of L-ascorbic acid. The ethyl acetate fraction showed remarkable antioxidant and nitrite scavenging effects compared with the other fractions obtained from soybean, meju and doenjang. The ethyl acetate fraction of doenjang was fur-ther purified by repeated chromoatograpic methods and isolated three compounds. There are identified as genistin, dai-dzein and genistein on the basis of spectral data.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1842-1846
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• 2012

The effects of hurdle techniques on the reduction of Bacillus cereus spores in Doenjang and Gochujang were investigated. In our system, Bacillus cereus spores were artificially inoculated into Doenjang and Gochujang. Hurdle techniques used in this study were additives (3% ethyl alcohol-0.03% oregano extract), Joule heating ($95^{\circ}C$ for 5 min), and hydrostatic pressure (500 MPa for 5 min at $45^{\circ}C$). Additive-Joule (AJ) and additive-Joule-pressure (AJP) treatments for Doenjang resulted in a 2.80 log and 3.74 log reduction, respectively, while treatments for Gochujang resulted in a 4.71 log and 5.60 log reduction, respectively. This suggests a high synergistic effect of Joule heating with additive treatment in Doenjang and Gochujang. A combination ofg hurdles such as additives, Joule heating, and hydrostatic pressure also kept Bacillus cereus spore counts low during storage at $30^{\circ}C$. Therefore, Bacillus cereus spores inoculated into Doenjang and Gochujang can be effectively reduced through combined treatments, including AJ or AJP.