• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.777-781
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• 2001

The effects of gamma-irradiation on the nutritional components of some Korean soybean-based fermentation foods were studied. Doenjang (soybean paste), kochujang (red pepper paste) and chungkukjang were prepared, irradiated at 0, 5, 10 and 20 kGy, and their compositions of free amino acid, free fatty acid and organic acid were determined. Compositions of free amino acid and free fatty acid in gamma irradiated sample were stable compared to non-irradiated control. Content of citric acid and succinic acid increased, while that of malic acid decreased in the gamma irradiated chungkookjang, but there were no significant changes in organic acid composition in organic and kochujang.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.341-347
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• 2022

In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. Weissella koreensis and Pediococcus inopinatus were the dominant species according to the NGS results, while Bacillus species and P. inopinatus were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five Bacillus strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity. Strains were then assessed for salt tolerance and protease and lipase activity. As a result, four strains-B. safensis GN5_10, B. subtilis GN5_19, B. velezensis GN5_25, and B. velezensis GT8-were selected as safe starter candidates for use in fermented foods.

• Journal of the Korean Society of Food Culture
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• v.36 no.3
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• pp.265-273
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• 2021

The Chinese Sigyeong records the foods of the Primitive Pickling Period, pickling being a universal vegetable storage method, but does not indicate the origin of the pickled vegetables or the location of the source of transmission. Kimchi mainly used salt and sauce-based soaking materials at the beginning of the Fermented Pickling Period (beginning in the 1st to 3rd centuries A.D.), and it differed from the Chinese method, which used alcohol and vinegar. In the Umami-Flavored Pickling Period (beginning in the 14th and 15th centuries A.D.), jeotgal, fermented seafoods, were added, and pickles with a completely new identity were created, one different from any other pickles in the world. Lastly, entering the Complex Fermentation and Pickling Period (beginning in the 17th and 18th centuries), the technical process evolved using a separate special seasoning containing red pepper as the secondary immersion source after pickling in brine, the primary immersion source. As a result of this, kimchi was transformed into a food with a unique form and taste not found anywhere else. The unique characteristic of kimchi is that the composition of original materials, a combination of salted marine life and vegetable ingredients, is its core identity, and there is a methodological difference in that it is completed through a second process called saesaengchae (生菜)-chimchae (沈菜).

• Journal of Dairy Science and Biotechnology
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• v.40 no.1
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• pp.23-34
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• 2022

In this study, to determine the importance of lactic acid bacteria (LAB) in Kombucha fermentation, biological functions, such as organic acid production and anti-inflammatory and antibacterial activities, of Kombucha, with or without LAB inoculation, were evaluated. Lactobacillus paracasei DK215, Saccharomyces cerevisiae C3, and Acetobacter pasteurianus P2 were selected as the inoculants. Organic acids were measured every 3 days from the end of fermentation using HPLC; the organic acid content of LAB-inoculated Kombucha was relatively high. Samples with or without LAB inoculation showed high antibacterial activity against Escherichia coli. The MTT assay results indicated no significant difference in concentration difference and cell death. In the NO production test, compared with the uninoculated Kombucha sample, the LAB-inoculated Kombucha sample exhibited a value similar to that of the group without LPS treatment. The levels of cytokine (IL-1α, IL-6, TNF-α) production were significantly lower than those of the LPS(+) group, indicating the anti-inflammatory activity potential of the Kombucha sample. This improvement in the biological function of the LAB-inoculated Kombucha further verifies the value of LAB in the fermented food and beverage industry.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.780-787
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• 2023

Two mannitol producing lactic acid bacteria were isolated from pa (green onion)- kimchi, identified and named as Leuconostoc mesenteroides SKP 88 and Leuconostoc citreum SKP 92, respectively. Both isolates grew well at 25-30℃, initial pH 6-8, and 3% and lower NaCl concentration. Both isolates converted fructose into mannitol efficiently when grown on MRS broth containing fructose and glucose. Glucose was used as a carbon source and fructose was used as a precursor for mannitol. Mannitol yields were the highest in MRS broth with 3% fructose and 2% glucose. Shine muscat juice fermentation was done using each isolate as a starter. As fermentation progressed, decrease in pH and increases in titratable acidity and viable counts were observed. L. mesenteroides SKP 88 showed better mannitol conversion ability than L. citreum SKP 92, and shine muscat juice fermented with L. mesenteroides SKP 88 showed the mannitol production of 41.6 g/l at 48 h, and juice fermented with L. citreum SKP 92 showed 23.4 g/l at the same time. Yogurt fermentations showed similar patterns, and yogurt fermented with L. mesenteroides SKP 88 showed the mannitol production of 15.13 g/l. These results showed that both strains are useful as starters for healthy fermented foods with reduced fructose contents.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1961-1967
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• 2006

Levels of ethyl carbamate, a potential carcinogen produced naturally during fermentation, in major Korean fermented foods and alcoholic beverages were determined by GC/MS/SIM, and their average daily intake and excess cancer risk in Korean people were estimated. In GC/MS/SIM analysis n.d.-4.26, 1.40-58.90, n.d.-3.76, n.d.-1.87, and 0.40-10.07 $\mu$g/kg of ethyl carbamate were detected in kimchi, soy sauces, fermented pastes, fermented dairy products, and alcoholic beverages, respectively. The average daily intake of ethyl carbamate and excess cancer risk through major Korean fermented foods and alcoholic beverage consumption were 6.0 ng/kg bw/day and $3.0\times10^{-7}$, respectively for the average Korean person aged 3-64 years, and were mainly contributed by Chinese cabbage kimchi, soy sauces, and Soju.

• KSBB Journal
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• v.32 no.3
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• pp.199-205
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• 2017

The aim of this study was to investigate probiotic characteristics and fermentation profile of selected lactic acid bacteria (LAB) isolated from traditional fermented foods. Antibacterial activity against various pathogens, acid and bile salt tolerance, cell hydrophobicity, and antibiotic resistance were examined. 16S rRNA sequencing was carried out to identify eight presumptive LAB isolates. In general, all identified LAB (Enterococcus faecium MG89-2, Lactobacillus plantarum MG207, L. paracasei MG310, L. casei MG311, Streptococcus thermophilus MG510, L. bulgaricus MG515, L. helveticus MG585, and L. fermentum MG590) showed strong antimicrobial activity. Also, the selected strains were resistant to bile acid up to 3% and their autoaggregation rates were as high as 60%. All selected strains tested were sensitive to chloramphenicol, tetracycline, and ampicillin, whereas resistant to nalidixic acid and kanamycin.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.519-524
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• 2011

The correlation between alcoholic fermentation rate, measured as carbon dioxide ($CO_2$) evolution, and the rate of hydrogen sulfide ($H_2S$) formation during wine production was investigated. Both rates and the resulting concentration peaks in fermentor headspace $H_2S$ were directly impacted by yeast assimilable nitrogenous compounds in the grape juice. A series of model fermentations was conducted in temperature-controlled and stirred fermentors using a complex model juice with defined concentrations of ammonium ions and/or amino acids. The fermentation rate was measured indirectly by noting the weight loss of the fermentor; $H_2S$ was quantitatively trapped in realtime using a pre-calibrated $H_2S$ detection tube which was inserted into a fermentor gas relief port. Evolution rates for $CO_2$ and $H_2S$ as well as the relative ratios between them were calculated. These fermentations confirmed that total sulfide formation was strongly yeast strain-dependent, and high concentrations of yeast assimilable nitrogen did not necessarily protect against elevated $H_2S$ formation. High initial concentrations of ammonium ions via addition of diammonium phosphate (DAP) caused a higher evolution of $H_2S$ when compared with a non-supplemented but nondeficient juice. It was observed that the excess availability of a certain yeast assimilable amino acid, arginine, could result in a more sustained $CO_2$ production rate throughout the wine fermentation. The contribution of yeast assimilable amino acids from conventional commercial yeast foods to lowering of the $H_2S$ formation was marginal.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.943-946
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• 2017

Although the genus Leuconostoc, generally found in various fermented foods, has often been suggested to be a novel probiotic for food fermentation and health promotion, the strains in this genus showed low acid tolerance and low osmotic stress resistance activities, which are required for survival during food fermentation events. Recently, a novel species of Weissella, W. jogaejeotgali $FOL01^T$ (= KCCM 43128 = JCM 30580), was isolated from Korean fermented clams. To determine the genomic features of this new species, its genome was completely sequenced and analyzed. The genome consists of a circular chromosome of 2,114,163 bp of DNA with a G+C content of 38.8%, and the plasmid pFOL01 consists of 35,382 bp of DNA with a G+C content of 39.1%. The genome analysis showed its potential for use in food fermentation and osmotic stress resistance abilities for processing in food industries. In addition, this strain was predicted to have acid tolerance and adhesion to the mucosal layer for survival and colonization in the gut. Subsequent experiments substantiated these abilities, suggesting that W. jogaejeotgali may have probiotic potential and a high survival rate during food fermentation. Therefore, it may be suitable as a novel probiotic strain for various applications in food industries.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.111-111
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• 2018

Aronia (black chokeberry), a species of berries is source to a very large number of bioactive compounds like polyphenols, flavonoids, anthocyanins, and tannins in comparison to any other species. Owing to its antioxidant, anti-carcinogenic, anti-aging and anti-inflammatory properties. Fermentation- a bioconversion process exploiting the biological metabolic reaction of micro-organisms, has several benefits like improving the efficacy and safety of physiologically active substances, generation of new functional material, improving the adsorption rate and many others. Antigens like pathogens, food, pollen etc., generate a protective immune response in body tissues, and the process be referred to as inflammation. However, this when excessive results in a condition referred to as refractory inflammatory disease, whose incidence is increasing in the recent times, especially amongst children. The current study intended to assess the anti-oxidant activity, presence of polyphenols and anti-inflammatory efficacy of Aronia extract fermented by Lactic acid bacteria isolated from fermented sea foods. Aronia fruits collected from Sunchang, Chonbuk were lyophilized for fermentation. So as to maximise the efficacy of the fermented Aronia extract, the quantitative effects of lactic acid bacteria species, composition of extraction solution, influence of temperature and time on antioxidant activity and total polyphenol contents were investigated using an experimental design. Anti-inflammatory activity was evaluated on NO and cytokine ($TNF-{\alpha}$, IL-6) production in LPS activated Raw 264.7 cells. Results indicated that antioxidant effect and total polyphenol contents were best improved in extract of Aronia fermented by P. pentosaceus. In addition, NO and cytokine ($TNF-{\alpha}$, IL-6) levels were decreased significantly after fermentation. Thus, it was found that the anti-inflammatory activity of Aronia greatly increased after fermentation process using P. pentosaceus.