• Culinary science and hospitality research
• /
• v.12 no.4 s.31
• /
• pp.225-235
• /
• 2006

This study was carried out to investigate the optimum conditions for the preparation of natto(unripe Chungkukjang) using Sowonkong(small soybeans) and Bacillus subtilis KCCM 11315. The changes in the contents of amino-type nitrogen, ammonia-type nitrogen, total acidity and total sugar, and those in the pH, browning materials and microbial growth were determined during fermentation and aging of natto(unripe Chungkukjang). The amounts of amino-type nitrogen and ammonia-type nitrogen were increased gradually during the fermentation at $40^{\circ}C$ for 72 hours, but those of total acidity and total sugar were decreased. The pH was gradually alkalized, and more water soluble browning materials were produced during fermentation. The number of viable cells was the highest at the 36 hours of fermentation. The content of ammonia-type nitrogen was significantly decreased during aging at $4^{\circ}C$ for 48 hours. In view of the results as above, it seems possible to conclude that the natto(unripe Chungkukjang) fermented by Bacillus subtilis KCCM 11315 at $40^{\circ}C$ for 36 hours and then aged at $4^{\circ}C$ for 48 hours was suitable for manufacturing natto(unripe Chungkukjang).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.5
• /
• pp.736-745
• /
• 2016

Cheonggukjang, a traditional Korean fermented soy food, was prepared by inoculation of Bacillus subtilis EMD4 or Bacillus amyloliquefaciens EMD17 with anti-bacterial or anti-fungal activities into soybeans. Cheonggukjang was also prepared by co-inoculation of EMD4 and EMD17 (1:1, v/v). Control cheonggukjang was prepared by using B. subtilis KACC16450 (Natto strain). Growth of B. cereus cells spiked with starter organisms was completely inhibited by B. amyloliquefaciens EMD17 after 12 h of fermentation at $37^{\circ}C$. Growth of B. cereus was also inhibited by B. subtilis EMD4, but the degree of inhibition was weaker. After 48 h of fermentation, cheonggukjang samples were stored for 10 days at $4^{\circ}C$. B. cereus cells were not detected from cheonggukjang inoculated with EMD4, whereas significant numbers still present in control. The pH values of cheonggukjang samples were not significantly different. During fermentation, cheonggukjang fermented with EMD17 showed the highest fibrinolytic activity and during storage, cheonggukjang fermented with a Natto strain was the highest. Cheonggukjang fermented with a Natto strain also showed the highest amount of total phenolic compounds. The results show that control of B. cereus in cheonggukjang is possible by using starters such as B. amyloliquefaciens EMD17.

• Journal of Life Science
• /
• v.19 no.2
• /
• pp.264-270
• /
• 2009

We investigated the effect of black soybean and doenjang with black soybean on production of cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) compared with yellow soybean and doenjang with yellow soybean. We also determined inhibitory effect of two types of soybeans and doenjang on tumor metastasis produced by colon 26-M3.1 carcinoma cells. The cytokine productions of mouse splenocytes increased by the exposure of lipopolysaccharide (LPS, 1 ${\mu}g$/ml) compared to without treatment of LPS. The LPS-induced IL-2 production was highest in the black soybean methanol extract, while the methanol extract from black soybean doenjang fermented for 2 mo showed the higher levels of IL-2 without LPS (p<0.05). In case of LPS-induced IL-6 production, the methanol extracts from control, yellow soybean, black soybean doenjang fermented for 2 and 7 mo showed higher levels of IL-6 compared to those of black soybean, and yellow soybean doenjang fermented for 2 mo (p<0.05). The methanol extract of black soybean doenjang fermented for 2 mo showed significantly higher levels of TNF-${\alpha}$ in both with and without LPS (p<0.05). In experiment of tumor metastasis, the treatment (1 mg/mouse) of methanol extract from black soybean doenjang fermented for 7 mo inhibited tumor metastasis by 50% and had the highest inhibitory effect among other samples (p<0.05). From these results, doenjang manufactured with black soybean modulated the production of cytokine and showed anticancer effect, suggesting that this effect was increased with increased periods of fermentation.

• Food Science and Preservation
• /
• v.17 no.3
• /
• pp.410-417
• /
• 2010

Several extracellular protease-producing bacteria were isolated from Chungkookjang, a traditional Korean food of fermented soybeans, on skim milk agar plates. Among these bacteria, strain D14 exhibited the highest production (15.2 U/mL) and specific activity (40.0 U/mg protein) of extracellular protease activity as assessed on growth in a protease induction medium composed of 1% (w/v) soluble starch, 1.5% (w/v) skim milk, 0.5% (w/v) yeast extract, and 2% (w/v) NaCl. The bacterium was identified as Bacillus subtilis based on morphological and physiological characteristics and 16S rDNA sequence. A BLAST search of 16S rDNA sequences revealed that the isolate was most closely related to Bacillus subtilis subsp. subtilis strain NCIB 3610. The 16S rDNA sequence homology was 99.9%. Our isolate produced the highest level of protease when grown in a protease induction medium containing 1% (w/v) sorbitol and 0.5% (w/v) yeast extract. Fructose and glucose reduced enzyme production to 12.7% and 35.9%, respectively, of the level seen when the strain was grown in medium containing soluble starch. Soytone also reduced enzyme production to 61.4% of the level noted when the strain was grown in medium containing yeast extract.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.1
• /
• pp.48-54
• /
• 2007

Bacillus polyfermenticus SCD (B. polyfermenticus SCD) has been appropriately used for the therapy of long-term intestinal disorders, because live strains in the form of active endospores can successfully reach the target intestine in humans. B. polyfermenticus SCD produces the most antibiotic-related materials. In the present study, B. polyfermenticus SCD was fermented with soybeans (BPFS) and its probiotic properties were investigated. B. polyfermenticus SCD and BPFS showed a broad spectrum of antimicrobial activity against pathogenic Gram-positive (Streptococcus parauberis, Streptococcus iniae, Lactococcus garviae) and Gram-negative (Flexibacter tractuosus, Vibrio harveyi, Vibrio vulnificus, Vibrio ordalii) bacteria and moulds (Aspergillus niger, Aspergillus oryzae). Sebastes schlegeli were used to examine survival rate and cleanup action by BPFS. Bacterial infection resulted in a mortality of up to 99% in the commercial fodder fed groups. BPFS both enhanced the growth rate of fry by improving their appetite and had cleaned by decreased eutrophication. Therefore, it seems appropriate that BPFS should be developed as an antibiotic replacement, favorable fodder additive, and antifungal material in fish farming systems.

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.251-256
• /
• 2008

Eoyukjang is a traditional sauce-type of Korean food that is similar to a soybean sauce made from fermented soybeans, and it is produced from a fermented mixture of sea foods, meats, and meju (soybean paste). This study examined periodical changes in the enzymatic activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, protease, lipase, and lipoxygenase within the culture broth and solids of eoyukjang during 1 year of fermentation. The eoyukjang solids had 234-532% higher protein content than the culture broth. The specific activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease increased in both the culture broth and solids. Particularly, in the culture broth, ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease activities rapidly increased (3- to 8-fold) until 10 months of fermentation, and then drastically decreased. However, the activities of lipase and lipoxygenase in both the culture broth and solids were less than 0.05 unit/mg of protein, respectively, throughout fermentation; thus, their activity levels were low and changed little over the 12 months. Overall, while the solids had higher protein content than the culture broth, the broth had greater enzyme activity levels during eoyukjang preparation.

• Korean journal of food and cookery science
• /
• v.21 no.2 s.86
• /
• pp.163-170
• /
• 2005

Soybean is an important plant as the source of protein and oil, as well as phytochemicals such as genistien, daidzein, phenolic acids, phytic acid, tocopherol, and saponin. Chungkukjang, a fermented soybean paste, is common in Korean meals and bacillus is usually used in the fermentation of steamed soybean. For its processing, whole soybeans are boiled in water until the beans are soft, and then the drained beans are wrapped with rice straw or starter and set in a warm place at $65^{\circ}C\;for\;3\;\~\;4\;days$. Normally, the remaining cooked water which was drained from the steamed beans is discarded. We supposed that this water possesses hish amounts of useful components, and we therefore developed a modified method using the cooked water. After fermentation, we added the remaining cooked water which had been drained from the beans to the fermented soy beans and boiled them together. To investigate the bio-functionality of the modified Chungkukjang, the total antioxidative activity, isoflavones contents, phenolic acids, and 3-deoxyglucosone (3-DG) were measured at each stage of the preparation of chungkukjang. The original and modified chungkukjang possessed a high antioxidative activity compared with the other samples, as did the drained water after steaming of the soybean. The contents of genistein, daidzein, and phenolic acids, which contained antioxidative activity, were also increased in the original chungkukjang and their contents were similar in the modified chungkukjang. The content of 3-DG was increased in the modified chungkukjang compare with the original. It is suggested that the active soybean components delivered to the drained water during the steaming process were useful for increasing the bio-functionality of the modified chungkukjang.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.10
• /
• pp.1687-1695
• /
• 2016

Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified as Aspergillus tubingensis M036 and M074 through sequence analysis of the beta-tubulin gene. After culturing both A. tubingensis isolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). Both A. tubingensis strains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by the A. tubingensis strains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest that A. tubingensis isolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.

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

• Nutrition Research and Practice
• /
• v.4 no.1
• /
• pp.23-29
• /
• 2010

Poly-gamma-glutamic acid ($\gamma$-PGA) is a mucilaginous and biodegradable compound produced by Bacillus subtilis from fermented soybeans, and is found in the traditional Korean soy product, cheongkukjang. This study was carried out to evaluate the effects of $\gamma$-PGA from a food source on the concentration of the neurotransmitter GABA and its metabolic precursor glutamate in diet-induced obese rats. Eight-week old male Sprague-Dawley rats (n=60) were used. The rats were divided into two groups and obesity was induced by providing either a 10% control fat or 45% high fat diet for 5 weeks. The rats were then blocked into 6 groups and supplemented with a 0.1% $\gamma$-PGA diet for 4 weeks. After sacrifice, brain and serum GABA and glutamate concentrations were analyzed by high performance liquid chromatography with fluorometric detection. The rats fed the high fat diet had significantly increased body weights. $\gamma$-PGA supplementation significantly increased serum concentrations of glutamate and GABA in the control fat diet groups while this effect was not found in the high fat groups. In the brain, glutamate concentrations were significantly higher in the $\gamma$-PGA supplemented groups both in rats fed the normal and high fat diets than in the no $\gamma$-PGA controls. GABA concentrations showed the same tendency. The results indicated that $\gamma$-PGA intake increased GABA concentrations in the serum and brain. However, the effects were not shown in obese rats.