• Korean Journal of Microbiology
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• v.53 no.1
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• pp.1-8
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• 2017

Measles virus is a highly contagious, exanthematic virus, preventable by the use of an effective live-attenuated vaccine. However, measles virus remains endemic in many area of the world causing nearly 200,000 deaths per year and still a major cause of child mortality, mostly in developing countries. In March 2014, Republic of Korea was certified as a 'national measles elimination' by the WHO as a result of a high-quality case-based surveillance system and population immunity, which was achieved by a high vaccination rate (>95.0% since 1996). But, since the beginning of 2014, the Gyeonggi province has experienced a resurgence of measles cases. In this study, we investigated the characteristics of measles viruses isolated from confirmed measles in Gyeonggi province during January 1, 2014 ~ July 31, 2014, 60 isolates were obtained from 72 confirmed measles specimens. Genotypic distributions and genetic diversities of isolated measles virus were analyzed by sequencing of nucleoprotein (N) gene. 58 (96.7%) imported cases were identified. The predominant genotype was B3, which reflects the circulating measles virus in adjacent countries. The sequences of nucleoprotein (N) gene of isolated MeV were showed that the strains characterized showed the highest degree of identity (99%) with the Philippine related strains in 2013-2014. Therefore, infected traveler returning from the Philippines transmitted secondary infection in Korea.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.589-595
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• 2001

Effect of anti-microbial agents, such as alcohol, garlic, chitosan, K-sorbate, or mustard, or pasteurization on the quality of traditional kochujang was investigated during storage at $30^{\circ}C$ for 24 weeks. Water activities of kochujang decreased after 12 weeks of storage. Consistency increased during storage and highest consistency of kochujang was obtained by the addition of mustard or garlic. Hunter a- and b-values decreased linearly as storage time passed. The degree of increase in total color difference$({\Delta}E)$ of alcohol added group was the highest among the tested anti-microbial agents. Gas was rapidly produced in the control and chitosan added group of kochujang. Capsanthin content decreased more rapidly in the group of alcohol, garlic or mustard added kochujang than the other group. Viable cell counts of yeast and aerobic bacteria in kochujang increased up to 12 weeks of storage, and then decreased slowly. The number of yeast was low in K-sorbate or alcohol added group. Activity of ${\alpha}-amylase$ decreased during storage, but that of ${\beta}-amylase$ increased in alcohol, garlic, K-sorbate added or pasteurized kochujang. Protease activities did not show any remarkable differences in the groups of tested during storage.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.254-259
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• 2003

Effects of freeze-drying on microbiological and sensory characteristics of yulmoo-kimchi (leaf radish kimchi) were investigated. Freeze-dried yulmoo-kimchi was stored at 0, 10 or $25^{\circ}C$ for 60 days and rehydrated with water. Optimum rehydration time of freeze-dried yulmoo-kimchi was 2 hr. Number of lactic acid bacteria of freeze-dried, 10 days-stored, rehydrated yulmoo-kimchi decreased significantly (p<0.05) in comparison with that of reference sample (non-freeze-dried yulmoo-kimchi), while no significant changes were observed after 10 days. As storage temperature increased, number of lactic acid bacteria of 10 days-stored samples decreased. pH value slightly increased by freeze-drying, while it decreased gradually during 60 days of storage. Sensory properties of freeze-dried/rehydrated sample were slightly inferior to those of reference sample, but those were relatively good when the sample was evaluated solely. Overall acceptability of freeze-dried, $0^{\circ}C$-stored, rehydrated sample was significantly inferior to reference sample (p<0.05) and it gradually decreased as storage temperature increased. Between storage periods of 10 through 60 days, sensory properties of 0 and $10^{\circ}C$-stored sample slightly decreased, while those of $25^{\circ}C$-stored sample decreased markedly.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.962-968
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• 2002

Effects of gamma-irradiation of 1 to 10 kGy on the microbial growth, contents of amino acids, fatty acids, and free sugars, and changes in acid values in soybean powder were studied. Irradiation doses at $3{\sim}5\;kGy$ inhibited the mold growth completely in two kinds of imported soybean powders. Contents of sulfur-containing amino acids, such as cysteine, in both soybean powders decreased with irradiation, whereas no significant changes in free amino acid and fatty acid contents of both soybean powders were observed. Free sugar contents of stachyose and sucrose in Chinese soybean powder decreased with increasing irradiation dose level, whereas, those of other sugars remained unchanged. Results of this study confirm that $3{\sim}5\;kGy$ irradiation can be safely applied to apply to soybean powder without causing significant quality deteriorations microbiologically and chemically.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.197-203
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• 2021

In this study, to develop a higher value-added makgeolli, the Korean traditional rice wine were made of four kinds of raw material cereals (wheat flour, puffed rice, non-glutinous rice, and glutinous rice). To investigate the development potential of makgeolli as functional materials, their physicochemical characteristics, phenol, flavonoid, and vitamin contents, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical scavenging activity were evaluated. Puffed rice makgeolli and non-glutinous rice makgeolli among four types of makgeolli were higher contents of alcohol (16-16.5%). Of four types of makgeolli, puffed rice makgeolli showed 5.2±0.06 mg GAE/mL, the highest level content of total phenol, and flavonoid contents of them were similarly high, with a level of 470-490 ㎍ QE/mL. Puffed rice makgeolli containing the highest level content of total phenol resulted in 81.5%, the highest activity of ABTS radical scavenging. These results suggest that puffed rice may be an effective raw material for makgeolli to be developed the antioxidant functional materials.

• Food Science and Preservation
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• v.13 no.3
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• pp.292-298
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• 2006

Effect of gamma irradiation on the microbiological and physicochemical characteristics of steamed waxy corns was determined in order to develop preservation techniques to enhance shelf-life during storage at room or low temperature. The initial total microbial count, and yeast & molds steamed waxy corns before irradiation were $2.1{\times}10^3CFU/g,\;1.9{\times}10^3CFU/g$, respectively. However, the total microbial count were completely inactivated and the count of yeast and molds were only 34 CFU/g at 3 kGy treatment When non-irradiated steamed waxy corns were stored at $25^{\circ}C$ for 7 months, the growth of total microbial counts and yeasts & molds were rapidly increased up to $7.1{\times}10^6CFU/g\;and\;1.9{\times}10^7CFU/g$, respectively. However, the total microbial counts at 3 kGy treatment and yeast & molds at 5 kGy treatment for 7 month storage were completely inactivated Similar result was observed at $15^{\circ}C$ and $4^{\circ}C$ storage. The Hardness of the irradiated steamed waxy corns and irradiation dose were not significantly different from those of the non-irradiated steamed waxy corns before storage, but the hardness of non-irradiated steamed waxy corns was significantly increased during the storage, compared to those of irradiated corns. The water content of both irradiated and non-irradiated steamed waxy corns after 7 month storage were significantly decreased from $65{\sim}60%$ to 30% but the changes of water content among treatments or irradiation doses were not significantly different during storage. Sugar contents in the irradiated steamed waxy corns were less free than those of non-irradiated samples and the amount of free sugar slowly increased as storage temperature increased. Sensory evaluation result showed that total sensory scores in irradiated steamed waxy corns were better than those of non-irradiated samples and total sensory scores were increased as irradiation doses increased.

• Korean Journal of Oriental Medicine
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• v.12 no.1
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• pp.49-57
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• 2006

Objectives : This study has attempted to establish an organized system for the microbiological quality of raw materials which are important factors in preparing the standard for microbial limits. Methods : This study has first set up microbial contamination limit test. total aerobic microbial count and total fungi count, int accordance with testing method of the Korea Pharmacopeia 8th edition in order to establish an inspection standard for microbial contamination. Results : The microbial contamination of 18 items that are highly prone to contamination by three regions(Seoul, Daejeon, Gyeongsangbuk-do), As a result, Morus alba Linne and Rehmannia glutimosa Liboschitz var. purpurea Makino showed as high contaminated by WHO's Microbial Contamination Limit standard. In case of Yukjin medicine in the Theory of Herb Medicinal Properties, total bacterial contamination rate showed as 17.7%, total fungal contamination rate showed as 41.2% and total aerobic mircobial count and total fungi count on Ephedra sinica Stapf. Pinellia ternate Breitenbach, Evodia officinalis Dode showed as high measured. The microbial conatmination rate materials which make up Yukmijihwanghwan were mostly high therefore the total aerobic microbial count was measured as high in case of Yukmijihwanghwan, the characteristics about microbial contamination strain is to be researched. Conclusions : By combining the basic data and experimental results related to microbial contamination of herb medicine, the most ideal storage standards for herb medicine has been attempted to be presented.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.97-107
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• 2015

Wetlands constitute a transitional zone between terrestrial and aquatic ecosystems and have unique characteristics such as frequent inundation, inflow of nutrients from terrestrial ecosystems, presence of plants adapted to grow in water, and soil that is occasionally oxygen deficient due to saturation. These characteristics and the presence of vegetation determine physical and chemical properties that affect decomposition rates of organic matter (OM). Decomposition of OM is associated with activities of various extracellular enzymes (EE) produced by bacteria and fungi. Extracellular enzymes convert macromolecules to simple compounds such as labile organic carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) that can be easily taken up by microbes and plants. Therefore, the enzymatic approach is helpful to understand the decomposition rates of OM and nutrient cycling in wetland soils. This paper reviews the physical and biogeochemical factors that regulate extracellular enzyme activities (EEa) in wetland soils, including those of ${\beta}$-glucosidase, ${\beta}$-N-acetylglucosaminidase, phosphatase, arylsulfatase, and phenol oxidase that decompose organic matter and release C, N, P, and S nutrients for microbial and plant growths. Effects of pH, water table, and particle size of OM on EEa were not significantly different among sites, whereas the influence of temperature on EEa varied depending on microbial acclimation to extreme temperatures. Addition of C, N, or P affected EEa differently depending on the nutrient state, C:N ratio, limiting factors, and types of enzymes of wetland soils. Substrate quality influenced EEa more significantly than did other factors. Also, drainage of wetland and increased temperature due to global climate change can stimulate phenol oxidase activity, and anthropogenic N deposition can enhance the hydrolytic EEa; these effects increase OM decomposition rates and emissions of $CO_2$ and $CH_4$ from wetland systems. The researches on the relationship between microbial structures and EE functions, and environmental factors controlling EEa can be helpful to manipulate wetland ecosystems for treating pollutants and to monitor wetland ecosystem services.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.477-484
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• 2017

This study was conducted to investigate the content of sulfur dioxide, carotenoids and the degree of contamination of Bacillus cereus in 33 kinds of dried sweet potato from domestic mainly dried agricultural products in Korea. According to the characteristics of dried sweet potato samples, it was classified into four clusters and as a result of analyzing the contents of sulfur dioxide, carotenoids and the degree of contamination B. cereus was no significant difference among the clusters. The detection ranges of residual sulfur dioxide from 33 dried sweet potatoes ranged from 0.38 to 28.16 mg/kg, three cases (9.09%) were detected at the reference level of 10 mg/kg or more. But no samples exceeding 30 mg/kg, the tolerance level of sulfur dioxide in dried sweet potatoes were detected. Since dried sweet potato does not have a standard for carotenoids, when comparing the national and international standards of carotenoids, the range of detection of carotenoids in dried sweet potato was $46{\sim}2,663{\mu}g$/100 g, which was within the reference range of $0{\sim}9,826{\mu}g$/100 g. In principle colonies suspected to be B. cereus in dried sweet potato were not detected. In 7 cases (21.21%), there were detected in the range of 0.05~1.59 log CFU/g but not more than 3 log CFU/g as the reference value. The results of this study are expected to be used as basic data to establish quality standard for dried sweet potatoes. In order to control the quality of dried sweet potatoes in domestic market, raw materials, drying method and packaging after distribution, it is necessary to maintain and maintain the process steadily.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.457-465
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• 2009

The characteristics of Holstein colostrum according to the methods that were employed in processing it were analyzed in this study to improve its industrial utilization. Colostrum samples were collected from the dairy farm of the National Institute of Animal Science (NIAS). The milk fat, protein, lactose, and SNF contents of colostrum were 4.34, 6.99, 3.37, and 11.10%, respectively. The effects of spray drying, freeze drying, freezing, acidification, and inoculation of lactic-acid bacteria on the characteristics of colostrum were then compared. The freezing of colostrum was found to be proper for long-term storage in a farm. Freeze-dried colostrum powder could not meet the processing requirements and the component standards for animal products in terms of the total bacterial and coliform bacteria counts, but spray-dried colostrum powder could meet the microbiological requirements because of its bactericidal effect during the spray-dry treatment. The inoculation of lactic-acid bacteria showed a better inhibitory effect on coliform than the acidification treatment, but protein precipitation appeared because of the low pH and the high acidity. To estimate the effects of the processing methods employed on the IgG of colostrum, the IgG contents of the milk treated by long temperature long time (LTLT) ($65^{\circ}C$, 30 min), by inoculating the lactic acid bacteria starter, by spray drying, and by freeze drying were measured. The IgG contents of the colostrum were changed significantly by the processing treatment employed, from 53.98 mg/mLto 33.28, 34.82, 21.98, and 36.89 mg/mL, respectively.