• 한국물환경학회지
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• 제29권6호
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• pp.808-812
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• 2013

A new type of microbial fuel cell (MFC) with anaerobic membrane filter was designed to produce bioelectricity and to treat domestic sewage at relatively high organic loading rate (OLR) of $6.25kgCOD/m^3/day$ and short hydraulic retention time (HRT) of 1.9 h. A following aeration system was applied to ensure effluent water quality in continuous operation. Glucose was supplemented to increase the influent concentration of domestic sewage. Influent substrate of 95% was removed via the MFC and following aeration system and the corresponding maximum power density was $25.6mW/m^3$. External resistor of $200{\Omega}$ and air-cathode system contributed better MFC performance comparing to $2000{\Omega}$ and dissolved oxygen as a catholyte.

• 한국식품조리과학회지
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• 제22권4호통권94호
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• pp.504-513
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• 2006

This study was performed to provide basic data for the operation of a safer cook-chill system by comparing and evaluating the quality of food prepared using the sous vide cook-chill(SVCC) and cook-chill(CC) systems, according to the preparation methods and storage temperature. When the effects of preparation methods and storage temperatures on the physicochemical and microbial qualities were analyzed, the following results were obtained. Firstly, the microbial risk was reduced and the food was raised when danhopark tzeam were prepared with SVCC compared with CC in which changes in pH and Aw and moisture content loss were less than with SVCC. Secondly, the storage period tested in this study was limited to only 10 days, which prevented any significant difference from being seen at 3$^{\circ}$C and 10$^{\circ}$C in the degradation of food quality when SVCC and CC were compared. However, the overall quality and safety as indicated by the physicochemical and microbial qualities at 10$^{\circ}$C were relatively low for and with CC, suggesting that SVCC is a more effective method, probably because vacuum packing eliminates oxygen in the food, thereby inhibiting bacterial growth.

• 한국식품저장유통학회지
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• 제11권1호
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• pp.7-11
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• 2004

저장조건이 딸기 “미녀봉”의 저장 중 품질 및 미생물학적 변화에 미치는 영향을 연구하기 위하여 저장 중 중량감소율, 부패율, pH 및 적정산도, 총균수 및 곰팡이와 효모 수의 변화가 측정되었다. 딸기 시료는 LDPE로 포장하여 4$^{\circ}C$와 2$0^{\circ}C$에서 각각 저장하였다. LDPE포장은 대조구에 비해 중량감소율 및 부패율을 감소시켰다. 또한 포장방법은 저장중 미생물학적 변화에 영향을 끼쳤는데 저장온도와 상관없이 대조구와 비교해서 효모와 곰팡이뿐만 아니라 총균수의 감소를 야기시켰다. 본 연구결과는 딸기 “미녀봉”의 유통기한을 고려할 때 4$^{\circ}C$에서 LDPE 포장으로 저장하는 것이 바람직하다는 것을 나타냈다.

• 한국축산식품학회지
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• 제44권2호
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.

• BMB Reports
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• 제45권7호
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• pp.377-389
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• 2012

Food fermentations have enhanced human health since the dawn of time and remain a prevalent means of food processing and preservation. Due to their cultural and nutritional importance, many of these foods have been studied in detail using molecular tools, leading to enhancements in quality and safety. Furthermore, recent advances in high-throughput sequencing technology are revolutionizing the study of food microbial ecology, deepening insight into complex fermentation systems. This review provides insight into novel applications of select molecular techniques, particularly next-generation sequencing technology, for analysis of microbial communities in fermented foods. We present a guideline for integrated molecular analysis of food microbial ecology and a starting point for implementing next-generation analysis of food systems.

• 한국가금학회지
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• 제27권1호
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• pp.25-30
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• 2000

Present study was conducted to investigate effects of microbial phytase in laying hen diets on utilization of non-phytate phosphorus(NPP) whose levels were adjusted to be adequate or lower than that of NRC requirements. Birds of control roup were fed a diet containing 0.275% NPP and 3.4% Ca, satisfying the NRC(1994) feeding standard. bird on T1, T2 and T3 were allowed to eat diets containing NPP at 100, 80 and 60%, respectively, of Control group, and 4.0% Ca level along with a microbial phytase added at a level of 300 DPU. Three hundred and sixty, ISA Brown layers, 23-week-old, divided into four treatment groups with three replications per treatment and 30 layers per replication were fed the diets for 12 weeks. Levels of feed intake were not different among the groups, The egg mass/feed intake ratio appeared better in T2 group by about 8%, though without a statistical significance, compared to that of control. Egg production fate tended to be improved over the control group by feeding the 100%(T1) and 80%(T2) NPP diets added with phytase, with a significant difference for T2(p<0.05). Mean egg weight and egg shell quality, measured by breaking strength and thickness of the egg shell, of the T2 group tended to show numerically better, without a significance than those of control. Furthermore, birds of the T2 group showed higher calcium and phosphorus contents in tibia by about 9%(p<0.05) than the control. Overall performances of birds in T1 appeared better than those of control, but tended to be lower than those of the T2. The birds in T3 performed similar to the those of the other dietary groups except the relatively low tibia calcium level. In conclusion, the results of this study suggest that supplementation of microbial phytase at a level of 300 DPU was effective to spare about 20% of NPP in laying hen diets without any adverse effects on production performances and bone quality.

• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.348-353
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• 2008

Aerobic bacterial growth on Korean pan.fried meat patties as a primary quality deterioration factor was modeled as a function of temperature to estimate microbial spoilage on a real.time basis under dynamic storage conditions. Bacteria counts in the stretch.wrapped foods held at constant temperatures of 0, 5, 10 and $15^{\circ}C$ were measured throughout storage. The bootstrapping method was applied to generate many resampled data sets of mean microbial counts, which were then used to estimate the parameters of the microbial growth model of Baranyi & Roberts in the form of differential equations. The temperature functions of the primary model parameters were set up with confidence limits. Incorporating the temperature dependent parameters into the differential equations of bacterial growth could produce predictions closely representing the experimental data under constant and fluctuating temperature conditions.

• 한국환경보건학회지
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• 제27권2호
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• pp.1-9
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• 2001

This study was carried out to investigate the microbial characteristics of the urban air pollution in the subway stations, streets, department stores, wholesale markets, underground shopping centers, buildings, parks, houses and apartments in the Seoul and the suburbs area. Total cell count, total mold count and the presence of opportunistic pathogens(Streptococcus pneumoniae, Klebsiella pneumoniae, Aspergillus spp., Penicillium spp.) were evaluated determine the microbial air quality. Total cell count and mold count of indoor air in the houses and apartments were 2.9$\times$10$^2$-6.3$\times$10$^2$cfu/㎥ and 60-1.8$\times$10$^2$cfu/㎥, respectively, and the department stores and wholesale markets had much lower cell count than the houses and apartments. Ground level of commercial stations were 2.6 fold higher than the general subway stations, and Apergillus spp. and Penicillium spp. which could cause the bronchus and lung diseases were detected 17 sampling site out of 45. Dust were collected from the commercial facilities and houses, and total cell and mold count of the dust were 4.3$\times$10$^3$-1.7$\times$10$^{6}$ cfu/g and 2.3$\times$10$^3$-6.5 $\times$10$^4$cfu/g, respectively. Therefore the dust might be one of the main reservoir of microorganims.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.172-176
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• 2012

Doenjang is a traditional Korean fermented soybean product that provides a major source of protein. In this study, a total of 18 different home-made doenjang samples were examined for the presence of foodborne pathogens and the total aflatoxin levels. Using an enzyme-linked immunosorbent assay to assess microbial quality and potential public health risk, we showed that total coliform levels in the doenjang samples ranged from 0 to $4.43{\pm}2.32{\times}10^6\;CFU/g$, and the maximum limit of Bacillus cereus was $4.67{\pm}2.0{\times}10^5\;CFU/g$. However, other foodborne pathogens, such as Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella spp., were not detected among the tested samples. One of the samples (S3) showed a maximum limit of $42.2{\pm}9.1\;{\mu}g/kg$ for aflatoxin levels, which was above the safety limit allowed by the Codex Alimentarius Commission (CAC) regulatory agency. Further research is necessary to determine whether and how doenjang safety can be improved via elimination/reduction of microbial contamination during fermentation and storage or using microbial starter cultures for its fermentation.

• 한국환경과학회지
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• 제20권5호
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• pp.575-580
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• 2011

This study characterized water quality of groundwater and purified water used for drinking water in 30 schools in Gyeongsangbukdo Province. The results of the study showed that 43% of groundwater and 45% of purified water were not suitable for drinking. Among them, microbial contaminations were the most serious problem. In raw groundwater, the exceeding rates of total colony counts was the highest in August (53.6%). Purified water samples showed higher rate of exceeding drinking water standard for total colony counts while showing lower rate of exceeding drinking water standard for total coliforms and fecal coliforms in March and August. Overall, proper managements for microbial contaminations are required for both groundwater and purified water. Furthermore, special attention should toward students not to drink water when groundwater or purified water exceeds the drinking water quality standard.