• The Korean Journal of Mycology
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• v.39 no.2
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• pp.151-153
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• 2011

In order to optimize storage conditions of Korean traditional Makgeolli, we brewed Korean traditional Makgeolli for 1 week with two-stage fermentations and investigated changes viable cell counts of yeasts and bacteria during storage for 1 month at $4^{\circ}C$ and $20^{\circ}C$. Yeast viable cell counts were decreased to 89.0% after storage for 30 days at $20^{\circ}C$, however, those were not significantly changed at $4^{\circ}C$ storage. Bacteria cell counts were decreased to 59.0% of initial cell counts for 30 days at $4^{\circ}C$. In the storage at $20^{\circ}C$, bacteria were significantly decreased to 98.0% of initial cell counts after storage for 30 days. Lactic acid bacteria were also similar to those of total bacteria cell counts at $4^{\circ}C$ storage, however, 99% of lactic acid bacteria were decreased at $20^{\circ}C$ storage for 30 days.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.495-504
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• 1997

Three media, i. e., MOD-SD, M98-5 and M98-5 supplemented with chicken fecal extract were tested as isolation media for anaerobic bacteria present in the duodenum, jeju-ileum and cecum of chicken. The results showed that the mean colony counts of medium M98-5 were similar with those of MOD-SD medium in all intestinal samples at the incubation periods of 2, 6 and 10 days. Supplementation with chicken fecal extract of M98-5 medium significantly increased (p < 0.05) the colony counts of bacteria from the duodenum, jeju-ileum and cecum. The colony counts at 6-day incubation were similar with those at 10-day incubation, but were much higher than the counts at 2-day incubation. The major types of bacteria found in the duodenum and jeju-ileum of chicken were tentatively identified as Lactobacillus, Streptococcus and E. coli. In the cecum, ten tentatively identified groups of bacteria, namely, Streptococcus, Staphylococcus, Lactobacillus, E. coli, anaerobic coccus, Eubacterium, Propionibacterium, Clostridium, Fusobacterium and Bacteroides were isolated. Anaerobes were found to comprise nearly the entire microbial population of the cecum. Predominating in all sections of the intestine were homofermentative lactobacilli. The main Lactotacillus species in chicken intestine were L. acidophilus, L. fermentum and L. brevis.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.214-220
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• 2008

Nitrifying bacteria were detected by fluorescent in situ hybridization (FISH) method at 6 sampling sites with different eutrophication degree in the Nak-Dong River and their tributaries. And conventional physico-chemical parameters including $NH_4-N$, $NO_3-N$, and TN were determined concurrently. In rainy period (July), there was no noticeable difference between the number of ammonia/nitrite-oxidizing bacteria detected at each site except Sang-Ju and the ratio of nitrifying bacteria to total counts stained by DAPI varied in 6~33%. By contrast, in the dry period (October), both of bacterial population was increased differently and the ratio of nitrifying bacteria to total counts ranged more widely from 6% in heavily polluted water zone, Hwa-Won to 60% in upper tributary with high agricultural land use. Byung-Sung-Chun. In January, the numbers of ammonia-oxidizing bacteria was reduced up to one tenth, while those of nitrite-oxidizing bacteria was apparently increased maybe due to high DO and low DOC.

• Food Science of Animal Resources
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• v.18 no.2
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• pp.107-114
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• 1998

This study aimed for the examination of quality characteristics and safety of potassium sorbate-free meat products. Therefore, experiments were carried out on the frankfurter sausage and pressed ham, which were stored at 4 and 30$^{\circ}C$ for up to 40 days. The potassium sorbate concentrations of the frankfurter sausage and pressed ham obtained from local market ranged from 1.087 to 1.449g / kg, which were below the permitted value as prescribed in the Korean Hygienic Regulation. At the 0 day the total aerobic bacterial counts of frankfurter sausage and pressed ham were in the level of around 103.0 and 103.4 CFU / g, respectively. However, they were prominently increased after 20 days at 4$^{\circ}C$ and 10 days at 30$^{\circ}C$ to higher than 105 CFU / g. After 30 days the counts were increased to 106.5 and 107.2 CFU / g, respectively. The growth curve of lactic acid bacteria was shown to be similar with that of total bacteria. the counts of lactic acid bacteria of the products stored at 4$^{\circ}C$ were 101∼102 CFU / g lower than those stored at 30$^{\circ}C$. Coliform bacteria was not detected in both of the products stored at 4$^{\circ}C$ even after 40 days storage, but after 10 days at the 30$^{\circ}C$. No significant differences in the microbial counts examined in this study were observed between frankfurter sausage and pressed ham. The biochemical tests on the isolated colonies from Clostridein agar showed no presence of Clostridium botulinum and Clostridium perfringens in the meat products examined. The pH of frankfurter sausage and pressed ham at the beginning was about 6.6, which level was maintained relatively constant during the storage at 4$^{\circ}C$, but it was increased after decrease to about 5.5 during the storage at 30$^{\circ}C$. TBA value was increased slightly till 30 days, but after that time increased sharply. VBN value was increased slowly during the whole storage, but it was more than 30 mg% for the samples stored at 30$^{\circ}C$.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.675-680
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• 2008

The physical quality and microbial safety of Korean beef jerky was evaluated at various steps during its preparation. Microbial counts in raw beef demonstrated mesophillic bacteria at 4.20 Log CFU/g, psychrotrophic bacteria at 3.85 Log CFU/g, anaerobic bacteria at 4.90 Log CFU/g, and yeast and molds at 1.92 Log CFU/g. Spore-forming bacteria and coliforms were not detected in raw beef samples. Spices and spiced meats showed similar trends in microbial counts, demonstrating minimal microbial contamination during these stages of preparation. The final beef jerky product exhibited counts of mesophillic bacteria at 1.15-1.66 Log CFU/g, psychrotrophic bacteria at 1.15-1.66 Log CFU/g, and anaerobic bacteria at 0.81-1.72 Log CFU/g. Spore-forming bacteria, yeast and molds, and coliforms were not detected in beef jerky. Significant differences from added ingredients occurred for instron textural profile analysis traits for hardness. In general, Korean beef jerky with humectant and tenderizer had lower hardness than control (without humectant and tenderizer). Also, the sample added with 0.01% protease from Streptomyces griseus had lower hardness than all samples. All samples had 0.7l to 0.72 water activities, and the color and pH were not shown in significant changes of all samples.

• Journal of Microbiology
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• v.42 no.4
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• pp.315-318
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• 2004

This study was undertaken to determine the suitability of tomato juice as a raw material for production of probiotic juice by four lactic acid bacteria (Latobacillus acidophilus LA39, Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Tomato juice was inoculated with a 24­h-old culture and incubated at $30^{\circ}C$. Changes in pH, acidity, sugar content, and viable cell counts dur­ing fermentation under controlled conditions were measured. The lactic acid cultures reduced the pH to 4.1 or below and increased the acidity to $0.65\%$ or higher, and the viable cell counts (CFU) reached nearly 1.0 to $9.0\times10^9/ml$ after 72 h fermentation. The viable cell counts of the four lactic acid bacteria in the fermented tomato juice ranged from $10^6\;to\;10^8\;CFU/ml$ after 4 weeks of cold storage at $4^{\circ}C$. Pro­biotic tomato juice could serve as a health beverage for vegetarians or consumers who are allergic to dairy products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.73-77
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• 1994

This study was conducted to investigate and make comparison between treatment which was reduced the reducing sugar content from Chinese cabbage using salting and desalting processes prior to Kimchi fermentation , and control for the effect of reducing sugar content on Kimchi fermentation at $25^{\circ}C$. In the early stage of Kimchi fermentation , the amount of reducing sugar (5.7mg/ml) in treatment was much smaller than that (15.1mg/ml) in control. Reducing sugar content of treatment decreased drastically during the first two days and then levelled off . Whereas, that of control dropped significantly up to the first four days of fermentation. pHs of treatment and control decreased significantly during the first two days and then showed gentle slopes. Acidities of treatment and control were increased continuously during the entire range of fermentation . The acidity of control reached to 0.75% in 3 days of fermentation, while that of treatment was shown after 6 days. Hardnesses of treatment and control using a puncture test were almost constant and the hardness value of treatment was higher than that of control during whole fermentation period. The total bacteria and lactic acid bacteria counts increased drastically during the first day of fermentation and the increase of total bacteria counts was mainly caused by that of lactic acid bacteria counts.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.448-457
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• 2012

The predictive ability for off-flavor development and quality change of ground beef was evaluated using a microbial time temperature indicator (TTI). Quality indices such as off-flavor detection (OFD) time, color, pH, volatile basic nitrogen (VBN), aerobic mesophilic bacteria (AMB) counts, and lactic acid bacteria (LAB) counts were measured during storage at 5, 10, 15, and $25^{\circ}C$, respectively. Arrhenius activation energies (Ea) were estimated for temperature dependence. The Ea values for TTI response (changes in titratable acidity (TA)), VBN, AMB counts, LAB counts, and freshness, which is defined based on OFD time for quality indices of ground beef, were 106.22 kJ/mol, 58.98 kJ/mol, 110.35 kJ/mol, 116.65 kJ/mol, and 92.73 kJ/mol, respectively. The Ea of microbial TTI was found to be closer to those of the AMB counts, LAB counts, and freshness. Therefore, AMB counts, LAB counts, and freshness could be predicted accurately by the microbial TTI response due to their Ea similarity. The microbial TTI exhibited consistent relationships between its TA change and corresponding quality indices, such as AMB counts, LAB counts, and freshness, regardless of storage temperature. Conclusively, the results established that the developed microbial TTI can be used in intelligent packaging technology for representing some selected quality indices of ground beef.

• the MEAT Journal
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• s.35 winter
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• pp.46-55
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• 2008

The microbiological and physicochemical properties of irradiated (2 kGy) or non-irradiated fermented meats processed with or without a commercial starter culture were evaluated during fermentation and aging. The pH of irradiated (2 kGy) fermented meats with starter cultures dramatically decreased during fermentation and aging (p<0.05), and the final pH was 4.25. The total aerobic counts and lactic acid bacteria counts reflected the addition of the starter culture. As the fermentation progressed, the total aerobic counts closely paralleled the lactic acid bacteria counts. The TBARS values of irradiated fermented meats increased regardless of the treatment during fermentation and aging. These results show that the irradiated(electron-beam) meat/fat resulted in the reduction of the total microbes and survives lactic acid bacteria. The use of starter cultures in meat batters post-irradiation may be useful for the production of fermented meats.