• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.74-83
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• 2016

In order to improve the sour taste and foul odor of fermented soymilk, bacteria were isolated from kimchi and identified. Of the 89 bacterial strains isolated from kimchi, 3 isolates produced fermented soymilk with a sour taste and foul odor. The selected bacterial strains R53, R83, and R84 were identified by morphological, biochemical, and 16S rRNA analyses as Weissella koreensis. The strain R83, which produced fermented soymilk having the mildest sour taste and foul odor, was selected for further investigation and named W. koreensis KO3. The optimum culture condition for the fermentation of soymilk by W. koreensis KO3 was at $30^{\circ}C$ for 12 h. When soymilk was fermented under the optimum culture conditions, the viable cell count reached up to $8.71{\times}10^8CFU/ml$ and pH and acidity reached as low as 6.02 and as high as 0.33%, respectively. Twenty-seven amino acids and their derivatives were detected in fermented soymilk. The amounts of serine, glycine, threonine, alanine, and aspartic acid, which contribute to a sweeter taste, increased during fermentation. Orinithine, which was not detected before fermentation, increased during fermentation. Sensory evaluation showed that W. koreensis KO3-fermented soymilk has improved bean, roasted nut, and sour flavors as well as an enhanced mouthfeel, appearance, preferability, and overall acceptability compared with those of standard fermented soymilk. With further study and development, soymilk fermented by W. koreensis KO3 could serve as a health-promoting food with favorable sensory qualities.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2094-2103
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• 2017

Aging is associated with distinct changes in immune cells and a decline in immune function, leading to increased susceptibility to infection and reduced responses to vaccination. Certain strains of lactic acid bacteria exert beneficial effects on the immune system. Previously, we reported that Weissella cibaria JW15 isolated from kimchi possesses immune stimulatory activity in vitro. In the present study, we further investigated whether oral administration of JW15 improves immune function in aged mice. Eighteen-month-old female mice were administered JW15 daily at low (JW15-L; $1{\times}10^8CFU/mouse$) or high dosage (JW15-H; $1{\times}10^9CFU/mouse$), or with Lactobacillus rhamnosus GG (LGG) using oral gavage. Two-month-old female mice were included as healthy young mice. After 4 weeks, the mice were euthanized and immune profiles were analyzed using whole blood and spleen. In complete blood count analysis, the numbers of white and red blood cells were significantly increased in the JW15-L group compared with those in the old mouse (OM) control group. In addition, administration of either JW15 of LGG resulted in higher numbers of splenocytes in comparison with the OM group. Furthermore, proliferative potentials were higher in all probiotic groups than OM. Cytokines such as IFN-${\gamma}$ and IL-6 were secreted at higher levels in splenocytes isolated from JW15-fed mice than in OM control mice. Similarly, mRNA expression of various cytokines was altered in the JW15 groups. Collectively, these results suggest that JW15 supplementation induces immunomodulatory effects in aged mice and indicate JW15 as a potential probiotic strain to improve immune function in aged animals.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.807-814
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• 2015

This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h. The total polyphenol and anthocyanin content of FDMJ yogurt was higher than that of control due to the presence of phytochemical contents in mulberry. Moreover, antioxidant activity such as DPPH and reducing power was highest 5% FDMJ yogurt. During cold storage, pH decreased or remained constant in all yogurts with values ranging from 4.08 to 4.78 units. In sensory evaluation, the score of 1% FDMJ yogurt was ranked higher when compared with other yogurts. It is proposed that mulberry fruit juice powder can be used to improve sensory evaluation and enhance functionality of yogurt.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.25-31
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• 2017

This study was conducted to find means to reduce the foul smell emitted from chicken manure. Rice water was inoculated with Lactobacillus sakei and then examined to determine the bacterial survival rates during storage, and whether fermentation had occurred. Rice water was an excellent medium for the growth of L sakei, given that a viable cell count was maintained for 15 days during storage at $4^{\circ}C$ and decreased slightly thereafter. Furthermore, microorganisms in chicken manure were separated and 14 species were identified. The antibacterial activity of an L. sakei supernatant against the identified microorganisms was measured using the agar diffusion method. The growth of 11 out of 14 species was inhibited, and only Corynebacterium variabile, Enterococcus faecium, and Raoultella ornithinolytica survived. Rice water was fermented by inoculation with L. sakei and mixed with chicken manure, and the quantities of ammonia, ethyl mercaptan, and hydrogen sulfide were measured after 48 hours. Emissions of ammonia and ethyl mercaptan were reduced significantly.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.1-8
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• 2018

Gul (oyster) jeotgals (GJs) were prepared using different types of salt (23%, w/v): purified salt, solar salt aged for 3 years, and bamboo salt crystalized 3 times. One set of GJs was fermented with Bacillus subtilis JS2 ($10^6CFU/g$), while the other GJ set was fermented without starter. During fermentation for 24 weeks at $15^{\circ}C$, the starter GJs showed 10-fold higher bacilli counts than the no-starter GJs, where the maximum bacilli count was $8{\times}10^3CFU/g$. All 28 bacilli strains isolated from the 6-week GJs were identified as B. subtilis by using a RAPD-PCR, indicating that some of the B. subtilis JS2 cells remained viable. Lactic acid bacteria (LAB) and yeasts were present at low levels, $10^1-10^2CFU/g$. LAB with protease activities isolated from 10-week samples were identified as Enterococcus species. The isolates obtained at 16 weeks were all Staphylococcus species. The GJs with bamboo salt showed higher pH and lower titratable acidity (TA) values than the other GJs due to the strong alkalinity of bamboo salt. The amino-type nitrogen in the GJs increased slowly during the fermentation. At 24 weeks, the GJs with purified salt showed the highest amino-type nitrogen (412-430 mg%), followed by the GJs with solar salt (397-406 mg%) and GJs with bamboo salt (264-276 mg%). Meanwhile, the GJs with bamboo salt showed the highest ammonia-type N (63.67 mg%), followed by the GJs with purified salt (49 mg%) and solar salt (48 mg%).

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.114-119
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• 2003

The fermentative conversion of food wastes into probiotic feed was investigated by seeding of mixed inoculum of Lactobacillus acidophilus and Saccharomyces cerevisiae. After grinding finely, optimal fermentation conditions for aeration was investigated at $30^{\circ}C$, The viable cell count of lactic acid bacteria and yeast during fermentation were monitored by controlling aeration rate at each different aeration degree of 0v.v.m 0rpm, 0.25v.v.m 100rpm, 0.5v.v.m 200rpm, and 1v.v.m 500rpm respectively. The most active growth of the yeast was shown at 0.5v.v.m 200rpm as $4.5{\times}10^9CFU/m{\ell}$. By controlling aeration rate, the pH of the probiotics feed could be controlled between 4-5 for the enhancement of preservation characteristics and acceptability for cattle feeding.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.746-750
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• 1999

The effects of electron-beam irradiation on the microbial and sensory qualities of pork loins were studied. The pork loins were aerobically packed in polyethylene films and exposed to absorbed doses of electron-beam at 0, 0.5, 1 and 2 kGy in ambient temperature. All samples were stored at $4{\pm}1^{\circ}C$. As an irradiation dose increased, decontaminating effects increased in terms of total microbial count, lactic acid bacteria and psychrotrophs during storage. All difference degrees in the triangle test were very low levels. In the descriptive analysis, Low dose irradiation did not affect aroma, off-flavor and acceptability in fresh and cooked meats.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.188-197
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• 2010

In this study, the quality characteristics and storage properties of gat kimchi added with oyster shell powder and Salicornia herbacea powder were investigated during a storage time of 80 days at $5^{\circ}C$. After storage for 80 days, the average calcium contents were significantly higher in the kimchi containing the oyster shell powder and Salicornia herbacea powder than the control. In addition, the average hardness value was significantly higher in the OS4 group(oyster shell powder at 4% and Salicornia herbacea powder at 2%) than the control group, as well as the OS10 group(oyster shell powder at 10% and Salicornia herbacea powder at 2%) during storage for 80 days. The hunter b value of the OS4 group was significantly lower than the control group. During fermentation, gat kimchi containing the oyster shell powder and Salicornia herbacea powder had a higher pH and a lower acidity value than the control group. In terms of sensory evaluation, there were no significant differences between the control and calcium-added kimchi during fermentation. After 40 days of storage, the OS4 group showed a lower total viable count, as well as lower lactic acid bacteria, yeast and E. coli, as compared with the control and OS10 groups. Based on the microbial load, the gat kimchi containing the oyster shell powder showed limitations in terms of shelf life.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.588-595
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• 2014

To develop a variety of salted vegetables, this study investigated the quality properties and sensory characteristics of pak-choi Baikkimchi with 0, 1, 3, 5 and 7% (w/w) red pepper seed during 50 days at $10^{\circ}C$. The pH of pak-choi Baikkimchi decreased little for the first days but decreased significantly after day 20. The larger amount of the red pepper seed kept pH the less affected. The total acidity of pak-choi Baikkimchi increased within 20 days. Lactic acid bacteria count, pak-choi Baikkimchi with 0% red pepper seed decreased after 30 days' increase, while pak-choi Baikkimchi with 3% and 5% red pepper decreased significantly after 20 days' increase. Hunter's color L value increased during storage but a and b value decreased. Pak-choi Baikkimchi with 0%, 5% and 7% red pepper seed on day 10, pak-choi Baikkimchi with 1% 3% red pepper seed on day 20. Flavor preference was higher on day 20 of storage. In taste analysis, pak-choi Baikkimchi with 3% and 7% red pepper seed higher preference on day 10 and with 5% on day 30. Appearance preference was higher for pak-choi Baikkimchi with 0% and 3% red pepper seed on day 10 and with the others on day 20. Texture preference decreased as the storage time. Overall preference of pak-choi Baikkimchi with 0%, 1% and 7% were higher on day 10, pak-choi Baikkimchi with 3% and 5% red pepper seed were higher on day 20. In conclusion, the quality properties and sensory characteristics of pak-choi Baikkimchi were optimal on day 20 of storage and 3% red pepper seed.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.470-477
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• 2001

This study was conducted to investigate the effect of garlic on the fermentation and organoleptic quality of kimchi. For this study, changes in pH, acidity, reducing sugar content and microbial count of kimchi during fermentation were tested and sensory test of fermented kimchi was also conducted. The acidity of kimchi with garlic was increased rapidly more than control kimchi at early stage of fermentation. Though the reducing sugar content was higher in kimchi with garlic than control kimchi, but that of all samples were almost same at mature stage of fermentation. Total bacteria and lactic acid bacterial counts were higher in kimchi with garlic than control kimchi at early stage of fermentation, but those were reversed at final stage of fermentation. By the result of sensory test, garlic was contributed to taste and aroma positively at level of $2{\sim}3g$ garlic to 100g of kimchi.