• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.273-279
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• 2013

The microorganisms producing high protease activity and acid producing ability were isolated from Chunggukjang and kimchi, which were identified as Bacillus subtilis and Lactobacillus planetarum by morphological, biochemical and nutrient requirement. The attempt was made to produce soybean milk yoghurt by using the isolated microorganisms. The mixed culture of Bacillus subtilis and Lactobacillus plantarum exhibited the lowest pH value of 4.23 and highest titratable acidity of 0.88% compared to those of single cultures at $37^{\circ}C$ for 32 hrs, and their total viable count was $4.09{\times}10^8$ $cfu/m{\ell}$. The ${\alpha}$-amylase activity was the highest in culture of Bacillus subtilis after incubation for 24 hrs, while protease activity was most produced in mixed culture of Bacillus subtilis and Lactobacillus plantarum. The amounts of reducing sugars were steadily decreased as soy milk fermentation progressed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.313-318
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• 2010

This study was carried out to evaluate the antioxidant activity of stevia extracts from Stevia rebaudiana Bertoni leaves. Stevia extracts were prepared by three different methods including hot water extraction (HWE) at $120^{\circ}C$ for 4 hr, vacuum extraction (VE) at $65^{\circ}C$ for 4 hr under 0.08 MPa, and fermentation of hot water extract (FHWE) using Lactobacillus buchneri. The antioxidant activities measured by radical scavenging activity, ferric-reducing antioxidant potential ability, and thiobarbituric acid reactive substance showed the highest values in vacuum extract. Also, the antioxidant activities of all extracts were higher than those of stevioside and rebaudioside at the same concentrations, known as the major active components in stevia. To define the antioxidative compound in stevia extracts, the total phenol content was measured, and it was shown that the highest contents of total phenolic compounds were in vacuum extract. These results suggest that the antioxidant activity of stevia extract was due to the phenolic compound components. In addition, vacuum extraction was the proper method to prepare stevia extract with higher antioxidant activity.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.84-97
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• 2016

Isolates from Korean fermented soybean paste were identified as Enterococcus faecium SBP12, Pediococcus halophilus SBP20, Lactobacillus fermentum SBP33, Leuconostoc mesenteroides SBP37, Pediococcus pentosaceus SBP41, Lactobacillus brevis SBP49, Lactobacillus acidophilus SBP55, and Enterococcus faecalis SBP58 according to conventional morphological and biochemical characteristics, carbohydrate fermentation profiling, and 16S rRNA sequence comparison. Strain SBP20, SBP33, SBP49, and SBP55 showed very resistance to simulated gastric and intestinal juices with final populations exceeding 6 log CFU/ml, whereas cells of SBP12 and SBP58 after exposure to low pH were dramatically decreased within 2 h. Among 4 strains having good tolerance to gastrointestinal conditions, the high adhesive ability to HT-29 cells, antibiotic resistance, and antimicrobial activity against food-borne pathogens Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 were observed with SBP49 and SBP55, therefore, these two strains were confirmed as putative probiotic candidates. There was no significant difference between the sourdoughs fermented with SBP49 and SBP55 with respect to the values of pH, total titratable acidity, and viable cell count. During sourdough fermentation, SBP49 strain produced significantly greater amounts of lactic acid than SBP55 strain, which secreted large quantities of hydrogen peroxide. SBP49 and SBP55 strains producing the antimicrobial substances such as lactic acid, hydrogen peroxide, and bacteriocin effectively inhibited B. cereus and S. aureus inoculated in the sourdough.

• KSBB Journal
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• v.27 no.1
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• pp.67-74
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• 2012

In this study, the optimum conditions of fermentation were determined by isolating the microorganisms with the ability to bioconvert the Citrus peel flavonoid, and the effect of the fermented Citrus peel extract which was bioconverted on the oxidative damage of HIT-T15 cell was investigated. The Aureobasidium pullulans Y-12 was isolated and identified with the strains having bioconversion activity. The fermentation conditions for bioconversion activity were confirmed to be optimal when culturing for three days at $25^{\circ}C$, 150 rpm in a culture medium containing 5% Citrus peel power and 0.8% casitone. As a result of bioconversion, 32.8 mg/g and 21.5 mg/g of naringenin and hesperetin, which were aglycone flavones, were produced respectively. Also in the flavonoid content, it was confirmed that FCP produced 154.8 mg/g while CP produced 33.7 mg/g, thus producing more by approximately 4.6 times. As a result of treating FCP and CP after inducing the oxidative damage for HIT-T15 cell by treating the deoxy-D-ribose with $IC_{50}$ (38 mM) concentration, the surviving rate was recovered to 90% for FCP treatments in the 0.01 mg/mL concentration and for CP treatments in the 0.025 mg/mL concentration. Also in the insulin secretion rate, FCP treatments increased by 206% and CP treatments by 132% when treated in the 0.1 mg/mL concentration. As the bioconverted FCP can inhibit the oxidative damage of HIT-T15 cell in the low concentration, it was considered its usability as the functional material for prevention of the type 2 diabetes.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.160-163
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• 2006

Brown rice contains rice bran and germ with higher nutritional value and dietary fiber content compared with the polished rice. However, brown rice has a limitation of poor digestion. fermented brown rice could be better nutritional source and improve digestibility. Therefore, we tried to select good fermentative microorganisms which have nutritional values with high amylase and protease activities, and probiotic effects. Nineteen micro-organisms, including eight Bacillus strains isolated from Chongkukjang and 11 lactic acid bacteria, were screened for the fermentation ability and enzyme production. The liquid broths containing 2.5%(w/v) of raw brown rice powder as a sole nutritional source were used for culture media. Among the strains tested, all of the Bacillus strains and two lactic acid bacteria (Leuconostoc gelidum and Pediococcus pentosaceus) showed increase in cell population and enzyme activities. The viable cell counts of all the Bacillus strains and two lactic acid bacteria exceeded $10^7 CFU/mL$. The maximal enzyme activities produced by Bacillus sp. Bl, Bacillus sp. B2, Bacillus sp. B11, L. gelidum and P. pentosaceus were 17.85, 17.50, 17.10, 17.10 and 3.24 U/mL for amylase and 22.48, 22.04, 23.76, 12.13, and 3.4 U/mL for pretense, respectively. Therefore, the results of this study demonstrated that the above strains could be potential starters for the fermentation of raw brown rice.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.142-146
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• 2010

Relatively large amounts of GABA can be produced by the fermentation of rice bran. Therefore, this study was conducted to investigate the effects of GABA on the secretion of melatonin and serotonin for the development of a sleep inductive compound. The secretion levels of melatonin and serotonin from mice were found to be $3.425{\pm}0.182\;pg/mL$ and $5.37{\pm}0.963\;ng/mL$, respectively, in response to feeding 120 mg/mL of GABA while they were $2.607{\pm}0.41\;pg/mL$ in the control. The secretion of both melatonin and serotonin was increased up to the 13.51% and 34.99%, respectively, when compared to the negative control. However, the feeding of milk alone did not have a great effect on the melatonin and serotonin secretions. Conversely, feeding of milk with GABA enhanced the secretion of serotonin. The amounts of both melatonin and serotonin secreted increased with respect to the increase in GABA concentrations during feeding. Interestingly, the induction level of melatonin was relatively higher than that of serotonin in response to feeding 120 mg/mL of GABA. This is the first study to report that GABA has an ability to induce sleep related hormones in mice; therefore, it has the potential for use as a natural sleep aid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.847-853
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• 2015

The purpose of this study was to compare color, protease, and antioxidant activities of Korean traditional soy sauce fermented for 120 days in Onggis obtained from five regions-Gangjin, Jeju, Ulsan, Yeoju, and Yesan in Korea. The brown color of soy sauce was increased during the fermentation period and was the highest in soy sauce fermented in Yesan. The values of total phenol contents, protease activity, and ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity activities were also increased during the fermentation period of soy sauce. Soy sauce fermented in Gangjin Onggi showed the highest protease activity, total phenol contents, DPPH radical scavenging activity, and FRAP ability. The partial least squares regression analysis indicated that the regional Onggis affect the quality of soy sauce with in terms of color, protease activity, and antioxidant activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.326-335
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• 2021

This study was undertaken to determine the effect of fermented soybean extract and its fractions on skin cell proliferation and growth. The extract was procured by the pepsin and Lactobacillus rhamnosus fermentation of soybean. LC-MS analysis was performed subsequent to soybean fermentation, and cell viability was measured by the WST-1 assay. Cell proliferation was observed to increase after exposing cells to the fermented soybean extract and its fractions at all concentrations tested (0~2,000 ㎍/mL). In particular, compared to the normal control group and 120 % proliferation of the EGF (epidermal growth factor) positive control group, 160~180 % cell proliferation was achieved at 800 ㎍/ml, indicating the excellent potential as an application material for skin aging inhibition and skin cell regeneration. In addition, we also examined the effects of fermented soybean extract and its fractions on wound healing ability, in HaCaT cells and fibroblasts. Our results indicate excellent cell migration abilities after treatment with fermented soybean extract and its fractions, as compared to the control treatment. Similar cell migration abilities were observed in the positive control group (EGF). Taken together, our results indicate that fermented soybean extract and its fractions (F4 and F5) exert amelioratory effects as a natural material for skin.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.735-742
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• 2017

This study was conducted to isolate and characterize Paenibacillus sp. MBT213 possessing ${\beta}$-glucosidase activity from raw milk, and examine the enzymatic capacity on the hydrolysis of a major ginsenoside ($Rb_1$). Strain MBT213 was found to have a high hydrolytic ability on ginsenoside $Rb_1$ by Esculin Iron Agar test. 16S rDNA analysis revealed that MBT213 was Paenibacillu sp. Crude enzyme of MBT213 strain exhibited high conversion capacity on ginsenoside $Rb_1$ into ginsenoside Rd proven by TLC and HPLC analyses. The API ZYM kit confirmed that Paenibacillu sp. MBT213 exerted higher ${\beta}$-glucosidase and ${\beta}$-galactosidase activity than other strains. Optimum pH and temperature for crude enzyme were found at 7.0 and $35^{\circ}C$ in hydrolysis of ginsenoside $Rb_1$. After 10 d of optimal reaction conditions for the crude enzyme, ginsenoside $Rb_1$ fully converted to ginsenoside Rd. Ginseng roots (20%) were fermented for 14 d, and analyzed by HPLC showed that amount of ginsenoside $Rb_1$ significantly decreased, while that of ginsenoside Rd was significantly increased. The study confirmed that the ${\beta}$-glucosidase produced by Paenibacillus sp. MBT213 can hydrolyze the major ginsenoside $Rb_1$ and convert to Rd during fermentation of the ginseng. The ${\beta}$-glucosidase activity of this novel Paenibacillus sp. MBT213 strain may be utilized in development of variety of health foods, dairy foods and pharmaceutical products.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.3
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• pp.235-244
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• 2009

This experiment was conducted to develop a new silage inoculant for barley at forage analysis laboratory, Grassland and Forages Division, National Institute of Animal Science, RDA from 2000 to 2002. Barley is very important crop in Korea. The great part of them is utilized as forage. Generally, it contains a lot of grains that are feed of animal, especially whole crop silage in ruminant. Efficient lactic acid bacteria were isolated from good barley silage by plating MRS agar containing 0.02% sodium azide, and assessed by growing and acid producing ability in MRS broth. Four lactic acid bacteria were selected, and were found to be Gram positive, rods and catalase negative and were identified to be Lactobacillus plantarum on the basis of the biochemical characteristics and utilization of substrates. Barley was ensiled at dough stage following treatment with four lactic acid bacteria, commercial inoculant, and no additive (control). After 2 months, B2-2 bacteria inoculated silage was lower pH and higher lactic acid content than others treatments. The Flieg's score and grade of B2-2 bacteria treated silage were higher than commercial inoculant. According to this experiment, Lactobacillus plantarum B2-2 (NLRI 201) was recommendable for good silage inoculant of whole crop barley silage.