• 한국식품영양학회지
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• 제31권2호
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• pp.308-312
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• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• 한국안광학회지
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• 제17권1호
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• pp.99-105
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• 2012

목적: 본 연구는 UVA영역의 LED를 이용하여 안질환을 일으키는 대표적인 유발균인 녹농균과 포도상구균에 대한 살균효과를 알아보고, UVA영역의 LED를 콘택트렌즈 살균에 활용하고자 하였다. 방법: 안질환의 원인 세균인 녹농균과 포도상구균에 대한 살균효과 실험은 400 nm의 UVA-LED를 이용하여 소형 살균기기를 제작하여 녹농균은 $10^{-7}$ CFU/ml, 포도상구균은 $10^{-5}$ CFU/ml 로 각각 액체배지에 희석하여 넣은 후 시간대별로 15분, 30분, 60분, 120분, 240분, 360분, 480분 동안 각각 400 nm의 UVA를 조사하였다. 결과: 살균실험 결과를 직선회귀방정식(regresson line equation)으로 변환하여 목표 살균치(target log inactivation)를 도출한 결과 녹농균에 대한 3log inactivation의 UV조사량($mJ/cm^2$)이 54,847 UV dose($mJ/cm^2$)이었으며, 조사시간(irridiation time)은 135.42(min) 이었다. 또한 포도상구균의 3log inactivation은 39,066 UV dose($mJ/cm^2$)이었으며 조사시간은 98.72분이었다. 결론: 이러한 실험 결과 400 nm의 UVA-LED를 이용한 녹농균과 포도상구균에 대한 뛰어난 살균효과를 확인하였으며 콘택트렌즈의 살균에 유용하게 이용될 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1209-1215
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• 2017

Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, $108^{\circ}C$ of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

• 한국환경과학회지
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• 제23권3호
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• pp.369-378
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• 2014

Effect of improvement of the dielectric barrier discharge (DBD) plasma system on the inactivation performance of bacteria were investigated. The improvement of plasma reactor was performed by combination with the basic plasma reactor and UV process or combination with the basic plasma reactor and circulation system which was equipped with gas-liquid mixer. Experimental results showed that tailing effect was appeared after the exponential decrease in basic plasma reactor. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of basic plasma process and UV process. The application of gas-liquid mixing device on the basic plasma reactor reduced inactivation time and led to complete sterilization. The effect existence of gas-liquid mixing device, voltage, air flow rate (1 ~ 5 L/min), water circulation rate (2.8 ~ 9.4 L/min) in gas-liquid mixing plasma, plasma voltage and UV power of gas-liquid mixing plasma+UV process were evaluated. The optimum air flow rate, water circulation rate, voltage of gas-liquid mixing system were 3 L/min, 3.5 L/min and 60 V, respectively. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of gas-liquid mixing plasma and UV process.

• 한국식품영양학회지
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• 제25권1호
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• pp.69-76
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• 2012

Intense pulsed light(IPL) has been highlighted as an innovative nonthermal sterilization technology that can kill spoilage or pathogenic microorganisms by using short-duration pulses of intense broad-spectrum electromagnetic radiation. This paper examines the inactivation effects of IPL on Listeria monocytogenes, Escherichia coli O157:H7, and Pseudomonas aeruginosa inoculated on seafood products such as salmon, flatfish, and shrimps and evaluates the possibility of extending the shelf-life of seafood products. The results indicate that the inactivation of microorganisms increased with an increase in IPL energy density($J/cm^2$) and a decrease in the distance between the sample surface and the lamp. In addition, temperature increases on the fish fillets during the treatments were well controlled within the range of 5.7~$9.8^{\circ}C$. The IPL treatment had a significant positive effect on the storage stability of seafood products at the storage temperature of $4^{\circ}C$ for 12 days. These results suggest that the storage period for fish fillets can be extended from 4 days to 6~8 days through the IPL treatment.

• 한국식품과학회지
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• 제45권2호
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• pp.248-251
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• 2013

김에 존재하는 M. roseus는 비병원성 세균이나 사람이 면역력이 떨어지게되면 질병을 일으킬 수 있는 균주로서 열처리를 통해서도 쉽게 사멸되지 않고 특히 10 kGy의 감마선 조사에서도 1 log, 40 kGy의 조사선량에서 1 log CFU/mL 이상의 생존율을 나타내는 방사선 저항 세균이다. 이러한 방사선 저항 세균인 M. roseus를 광펄스 살균을 통해 살균 가능성을 알아보았다. M. roseus는 빛의 세기가 증가함에 따라 사멸율이 증가하는 경향을 나타냈으며, 1,000 V의 빛의 세기에서 3분 처리 후에 6.4 log의 감소효과를 보였고 tailing 현상을 보이지 않았다. 빛의 세기와 처리시간을 같이 한 조건에서는 단위 시간동안 펄스 수가 높을수록 살균율이 높아졌으며, 10 pps에서는 2분의 처리로 모든 균이 사멸하였다. 또한 광원과 시료사이의 거리는 가까울수록 사멸율이 증가하는 경향을 보였다. 이러한 연구 결과로 볼 때 광펄스 살균이 향후 김의 위생적 처리의 방법의 하나로 가능성이 있을 것으로 예측된다.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2001년도 임시총회 및 제28차 추계학술발표회
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• pp.141-141
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• 2001

• Asian-Australasian Journal of Animal Sciences
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• 제15권4호
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• pp.596-601
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• 2002

The present study was designed to examine the effect of ozone treatment in microencapsulated ${\beta}$-galactosidase on inactivation of the enzyme and sterilization of microorganism. The efficiency was the highest as 78.4% when the ratio of polyglycerol monostearate (PGMS) was 15:1. Activities of lactase remaining outside the capsule were affected by ozone treatment. With the increase of ozone concentration and duration of ozone treatment, the activity reduced significantly. In sensory aspect, with 2% microcapsule addition, no significant difference in sweetness was found compared with a market milk during 12 d storage. Above result indicated that the additional washing process of lactase was not necessary to inactivate the residual enzyme. In a subsequent study, the vegetative cells of microorganisms were completely killed with 10 ppm for 10 min treatment by ozone. The present study provides evidence that ozone treatment can be used as an inactivation and a sterilization process. In addition, these results suggest that acceptable milk products containing lactase microcapsules made by PGMS can be prepared with ozone treatment.

• 공업화학
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• 제25권4호
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• pp.386-391
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• 2014

본 연구에서는 상압 저온 코로나 방전 플라즈마를 화산암재(스코리아) 분말의 살균에 적용하였다. 스코리아 분말에 Escherichia coli (E. coli) 배양액을 살포하여 균일하게 혼합한 후, 코로나 방전 플라즈마 특성 인자인 방전전력, 방전시간, 주입기체, 전극간격 등의 조건을 변화시키며 E. coli 살균효율을 조사하였다. 실험 결과 상압 저온 코로나 방전 플라즈마는 분말상의 스코리아 살균에 아주 효과적인 것으로 나타났으며, 방전전력 15 W에서 5 min 동안 살균한 결과 E. coli가 99.9% 이상 사멸하였다. 방전전력, 방전시간, 인가전압이 증가할수록 사멸율이 향상되었다. 반응기에 주입되는 기체의 종류에 따른 살균력 실험 결과, 산소 > 모사공기(산소 20%) > 질소 순으로 나타났다. 코로나 방전 플라즈마에 의한 E. coli 살균은 자외선과 활성산화종(산소라디칼, OH라디칼, 오존 등)에 의한 세포막 침식 및 에칭, 그리고 플라즈마 방전 스트리머에 의한 대장균 세포막 파괴로 설명할 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.230.2-230.2
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• 2016

A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite ($ONOO^-$-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli and different type of cancer cell through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria and cancer cell killing.