• 한국식품조리과학회지
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• 제20권6호
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• pp.589-597
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• 2004

This study was conducted to investigate the effects of various kinds of electrolyzed and chlorinated waters on the sensory and microbiological qualities of fresh-cut lettuce and to determine the most suitable electrolyzed water for the vegetable dishes, without heat treatment, at institutional foodservices. The sensory evaluation resulted in higher scores on the 1st-day of storage for the EW-1 (diaphragm type 1) and EW-3 (non-diaphragm type) compared to that for EW-2 (diaphragm type 2), with regard to their appearance, discoloration, texture, taste and overall acceptability characteristics. However, over time, EW-3 ranked highest, with a score of 8.00 (very like), on the 4th-day of storage, which maintained the highest level up to the 7th-day of storage, at which time the score was 7.00 (fairly like). The CW (chlorinated Water) had a significantly lower score, due to the smell of chlorine, although there was no concern with relation to chlorine residue from the electrolyzed waters. Microbial examinations of the total plate count revealed that immersing lettuce into EW-3 brought about l/3,000 to 1/30,000 reductions in the microbial counts of the TW treatment or untreated samples for up to seven days of storage. The CW treatment gave a 1/10 reduction in the microbial counts compared with the TW (tap water) treatment. The coliform bacterial counts also showed similar trends to those of the total plate count values. With regards to the psychotropic bacterial count, EW-3 was able to result in as much as a 1/30,000 reduction in the initial counts. As vegetable dishes, such as salad, can not be heat-sterilized, the utilization of EW-3 for the preparation of vegetable dishes without heat treatment will be an excellent choice to improve the critical control point in production state as a new effective means for sanitizing management.

• 한국수자원학회논문집
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• 제57권4호
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• pp.277-287
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• 2024

상수도 관망은 운영 중 다양한 수질 사고 발생 위험요소에 노출되어 있다. 본 연구는 다양한 수질 사고 위험요소 중 상수도 관망 내로의 바이러스 유입에 따른 위험도 평가 방법론을 제시하고, 이를 활용하여 위험도를 최소화할 수 있는 재염소 시설의 위치와 운영에 대한 검토를 수행하였다. 위험도 평가를 위해 QMRA (Quantitative Microbial Risk assessment)를 적용하였으며, 염소 농도에 따른 Water Quality Resilience를 정의하여 바이러스가 유입되지 않은 정상 운영 상황과 바이러스가 유입된 비정상 상황에서 염소 농도가 목표 범위(0.1-1.0 mg/L)내 운영되는지 여부를 정량적으로 확인하였다. 본 연구에서는 바이러스와 염소간의 반응을 고려해야 하기에, 다양한 수질인자를 고려할 수 있는 EPANET-MSX를 활용하여 수리 및 수질 분석을 수행하였다. 제안한 방법론은 미국의 Bellingham의 관망에 적용하였으며, 재염소 시설의 경우 0.5 mg/L부터 1.0 mg/L까지 주입 가능한 것으로 하였다. 적용 결과 재염소 시설이 없는 경우 Average risk가 0.0154이었으며, 재염소 시설 설치 후 1.0 mg/L의 농도로 주입 시 39.1%의 Average risk를 저감할 수 있었다. 다만, 재염소 시설을 통한 과도한 염소 주입은 Water Quality Resilience를 저감하여, 최종적으로 0.5 mg/L의 재염소 시설을 선정하였으며, 이를 활용하여 20% 가량의 Average risk 저감이 가능함을 확인하였다. 본 연구는 향후 잠재적 바이러스 유입에 대비한 재염소 시설의 설계에 활용할 수 있을 것이다.

• 한국식품위생안전성학회지
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• 제27권4호
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• pp.442-448
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• 2012

고춧가루의 LED(적색, 황색, 청색, 녹색광) 처리시 저장기간 중 미생물 저감화, 수용성 색소, capsanthin 함량, 표면 색도(Hunter L, a, b, ${\Delta}E$) 및 관능평가를 실시하였다. 저장기간 중 총 호기성 세균은 유의적인 차이를 나타내지 않았으며, 효모 및 곰팡이의 경우 황색 LED 처리군에서 1.76 log 감소되었다. 표면 색도는 저장기간이 경과함에 따라 모든 시료군에서 명도(L), 적색도(a) 및 황색도(b)가 유의적으로 감소하는 경향을 나타내었다. 전반적인 색차는 황색 LED 시료에서 ${\Delta}E$ 값이 3.0 이하로 나타나 다른 시료군에 비해 색도의 변화가 적은 것으로 나타났다. 수용성 색소는 저장기간 중 유의적인 차이는 나타나지 않았으며, capsanthin 함량은 저장기간이 경과함에 따라 감소하였으나 적색 LED 시료와 황색 LED 시료는 저장 10일 후 초기와 유의적인 capsanthin 함량 차이를 나타내지 않았다. 관능적 품질은 대조군의 경우 외관, 색 및 상품성이 저장기간 중 유의적으로 감소하는 경향을 나타내었으나 황색 LED 시료와 녹색 LED 시료는 유의적인 차이가 나타나지 않았다.

• 환경영향평가
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• 제19권6호
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• pp.617-623
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• 2010

It is the most important subject to figure out characteristics of the wastewater inflows of sewerage treatment plant(STP) when situation models are applied to operation of the biological processes and in the automatic control based on ICA(Instrument, Control and Automation). For the purposes, real-time influent monitoring method has been applied by using on-line monitoring equipments for the process optimization in conventional STP. Since, the influent of STP is consist of complex components such as, COD, BOD, TN, $NH_4$-N, $NO_3$-N, TP and $PO_4$-P. MRA2(Microbial Respiration Analyzer 2), which is capable of real-time analyzing of wastewater characteristics is used to overcome the limitations and defects of conventional online monitoring equipments in this study. Rapidity, accuracy and stability of developed MRA2 are evaluated and compared with the results from on-line monitoring equipments for seven months after installation in Full-scale STP.

• 상하수도학회지
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• 제20권4호
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• pp.627-635
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• 2006

Combined sewer overflow (CSOs) is a primary diffuse source degrading water quality of urban streams. In this study, CSOs caused by 5 different rainfall events at an urban watershed located in Daejeon city were monitored for the indicator microorganism concentrations. Event mean concentration (EMC) of the indicator microorganisms were: total coliform = $2.46{\times}10^6CFU/100mL$; fecal coliform = $1.01{\times}10^6CFU/100mL$; E.coli = $5.20{\times}10^5CFU/100mL$; and Fecal Streptococci = $6.08{\times}10^5CFU/100mL$. In addition, coliform concentrations were well correlated with suspended solid concentrations and the first flush effects were identified. Settling tests were carried out to estimate removal rate of indicator organisms by sedimentation from CSOs. As microorganisms are discharged in association with suspended solid, ten minutes of settlement can lower 44% of indicator microorganism leading.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1301-1313
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• 2021

This study investigated the effects of applying cellulase and starch on the fermentation characteristics and microbial communities of Napier grass silage after ensiling for 30 d. Three groups were studied: No additives (control); added cellulase (Group 1); and added cellulase and starch (Group 2). The results showed that the addition of cellulase and starch decreased the crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and pH significantly (p < 0.05) and increased water-soluble carbohydrate (WSC) content (p < 0.05). The addition of additives in two treated groups exerted a positive effect on the lactic acid (LA) content, lactic acid bacteria (LAB) population, and lactic acid / acetic acid (LA/AA) ratio, even the changes were not significant (p > 0.05). Calculation of Flieg's scores indicated that cellulase application increased silage quality to some extent, while the application of cellulase and starch together significantly improved fermentation (p < 0.05). Compared with the control, both additive groups showed increased microbial diversity after ensiling with an abundance of favorable bacteria including Firmicutes and Weissella, and the bacteria including Proteobacteria, Bacteroidetes, Acinetobacter increased as well. For alpha diversity analysis, the combined application of cellulase and starch in Group 2 gave significant increases in all indices (p < 0.05). The study demonstrated that the application of cellulase and starch can increase the quality of Napier grass preserved as silage.

• Animal Bioscience
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• 제35권8호
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• pp.1279-1288
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• 2022

Objective: The aim of this study was to investigate antioxidant activities of cinnamon (Cinnamomum cassia) extracts (extracted with different solvents) at various concentrations and to determine product quality of raw chicken patties added with different levels of cinnamon powder (CP) and oyster mushroon powder (OMP) during storage. Methods: After cinnamon was made into oven dried CP and extracted with water and different levels (50%, 80%, and 100%) of ethanol, antioxidant activities of these extracts were determined. CP and OMP were combined at different levels and added to raw chicken patties. Physicochemical properties and microbial counts were measured during refrigerated storage. Results: Cinnamon ethanol (80%) extract showed the highest (p<0.05) by 2,2-diphenyl-1picrylhydrazyl-radical scavenging activity and reducing power. Cinnamon water extract (CWE) had the highest iron chelating ability (p<0.05), while CP 100% ethanol extract had the highest content of total phenolic compound. Then, CP and OMP were applied to chicken patties at different levels (0.1% to 0.2%). After the addition of CPs, pH, L* (lightness), 2-thiobarbituric acid reactive substance, and volatile basic nitrogen values were decreased, whereas a* (redness) and b* (yellowness) values were increased. Microbial counts of total bacteria and Enterobacteriaceace were decreased with the addition of CP 0.2% regardless of the OMP level. Conclusion: The addition of CP in combination with OMP can increase the shelf-life of chicken patties during storage.

• 한국식품저장유통학회지
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• 제15권5호
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• pp.622-629
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• 2008

수도수(TW)와 0.5% sodium metabisulfite(0.5% SMS)를 대조구로 하고 강산성 전기분해수(SAEW: strong acidic electrolyzed water, pH 2.58, ORP 1,128 mV, HClO 105.0 ppm)와 약알칼리 전기분해수(LAEW: law alkaline electrolyzed water, pH 8.56, ORP 660 mV, HClO 73.8 mV)를 연근의 박피 후 침지액으로 하여 랩포장과 진공포장하여 $5^{\circ}C$ 저장 중 품질 변화를 비교.검토하였다. 0.5% SMS와 전기분해수 침지로 TW 침지 박피 연근에 비해 1 log cyle의 초기 균수 감소 효과와 저장중 상대적으로 낮은 균수를 나타내었다. 침지 처리에 의한 초기 및 저장중 경도의 차이를 나타내었으며 뚜렷한 PPO 활성을 저해하는 효과는 확인할 수 없었다. 전기분해수 침지로 표면색도와 색차는 0.5% SMS 침지와 유사한 억제 효과를 나타내었고 관능적 특성의 변화에서도 TW 침지 박피 연근에 비해 0.5% SMS 침지 박피 연근과 전기분해수 박피 연근이 다소 높게 평가되었다. 포장 방식에 있어서는 랩포장에 비해 진공포장이 품질 유지에보다 효과적이었다.

• 상하수도학회지
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• 제24권3호
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• pp.267-276
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• 2010

Many plants have been improved to adapt the target of the biological treatment processes changed from organics to nutrients since the water quality criteria of effluent was reinforced and included T-N and T-P for the municipal wastewater treatment plant. To meet the criteria of T-N and T-P, the conventional biological reactor such as aeration tank in activated sludge system is changed to the BNR (biological nutrient removal) processes, which are typically divided into three units as anaerobic, anoxic and oxic tank. Therefore, the solid separation process should be redesigned to fit the BNR processes in case of the application of the DAF (dissolved air flotation) process as an alternatives because the solid-liquid separation characteristics of microbial flocs produced in the BNR processes are also different from that of activated sludge system as well. The results of this study revealed that the microbial floc of the anaerobic tank was the hardest to be separated among the three steps of the unit tanks for the BNR processes. On the contrary, the oxic tank was best for the removal efficiency of nutrients as well as suspended solid. In addition, the removal efficiency of nutrients was much improved under the chemical coagulation treatment though coagulation was not indispensable with a respect to the solid separation. On the other hand, in spited that the separation time for the microbial floc from the BNR processes were similar to the typical particles like clay flocs, over $2.32{\times}10^3$ ppm of air volume concentration was required to keep back the break-up of the bubble-floc agglomerates.

• Food Science and Biotechnology
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• 제16권4호
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• pp.659-662
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• 2007

In order to determine the optimal storage conditions of Capsosiphon fulvescens (maesaengi), 2 types of wash solutions (distilled water and seawater) and storage temperatures (-20 and $-80^{\circ}C$) were evaluated for the effectiveness of microbial growth inhibition and the changes of texture, color, and proximate composition. Thawed samples that had been washed with seawater and stored at $-20^{\circ}C$ for 50 days showed a 1.1-fold increase in hardness compared to the initial hardness of the sample ($1.9{\times}10^5\;dyne/cm^2$). There was no change in moisture, ash, or crude lipid during storage at -20 and $-80^{\circ}C$ for 60 days, while there was a $1{\pm}0.2%$ decrease in crude protein content for the control during storage at both -20 and $-80^{\circ}C$ for 60 days. In conclusion, the recommended optimal storage conditions for retaining the quality of C. fulvescens are: temperatures at or below $-20^{\circ}C$ and washings with either distilled water or seawater for inhibiting microbial growth, temperatures at or below $-20^{\circ}C$ and a washing with seawater to prevent reductions in hardness, and a temperature of $-80^{\circ}C$ and washings with either distilled water or seawater to protect against color changes.