Ultraviolet-C 조사에 의한 복숭아의 저장 중 품질변화

장주희(Joo-Hee Jang),박재희(Jae-Hee Park),반기은(Ki-Eun Ban),이경행(Kyung-Haeng Lee) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.12

국내산 복숭아에의 저장성 증진을 위하여 0~10.0 kJ/㎡의 선량으로 UV-C를 처리하고 저장 중 부패율, 이화학적 변화 및 기호도의 변화를 측정하였다. 대조군 및 2.5 kJ/㎡ UV-C 처리군의 경우 부패율은 저장 4일까지는 부패된 것이 하나도 없었으나 저장 6일 이후부터는 부패된 복숭아를 보이기 시작하였으며 저장 10일에는 각각 29.17% 및 25.0%의 부패율을 나타내었다. 그러나 5.0, 7.5 및 10 kJ/㎡의 UVC 처리군에서는 저장 10일에 각각 41.67, 50.00 및 58.33%로 조사선량이 높을수록 더 많은 부패율을 나타내었다. 무게 변화의 경우 대조군과 2.5 kJ/㎡ UV-C 처리군은 저장 10일 동안 변화폭이 가장 적었으나 5.0 kJ/㎡ 이상의 처리군에서는 이들보다 많은 변화를 보였다. 복숭아의 pH 변화에서는 UV-C 처리에 의한 차이를 보이지 않았으며 저장기간 중 pH가 증가하였으나 모든 실험군에서 유의적인 차이가 없는 것으로 나타났다. 경도에서는 UV-C 처리 직후에는 모든 실험군에서 차이가 없었으나 저장 6일까지는 2.5 kJ/㎡ 처리군이 대체적으로 대조군과 비슷하거나 약간 높은 경도를 보였으며 저장 8일 이후에는 대조군보다 감소하였다. 그러나 5.0 kJ/㎡ 이상의 처리군에서는 저장 4일 이후부터는 빠르게 경도가 감소하는 것으로 나타났다. 명도 변화에서는 UV-C 처리 및 저장 중 모든 실험군에서 큰 차이를 보이지는 않았으며 적색도는 처리 직후에는 차이가 없었으며 대체적으로 저장 중 대조군과 마찬가지로 증가하는 경향이었다. 황색도는 UV-C 처리에 의하여 다소 황색도가 낮아졌으며 저장 중에는 모든 실험군이 약간 증가하였으나 유의적인 차이를 보이지는 않았다. 맛, 향, 색, 조직감 및 종합적 기호도의 변화에서는 UV-C 처리에 의한 변화는 없는 것으로 나타났다. 그러나 저장 중 모든 실험군에서 2일 혹은 4일차에 가장 높은 기호도를 보였으며 그 후부터는 기호도값이 감소하였다. 전반적으로 대조군과 2.5 kJ/㎡ UV-C 처리군이 가장 기호도가 높은 것으로 나타났다. To prolong the shelf-life of domestic peaches, samples were treated with UV-C (0~10.0 kJ/㎡) and the spoiling rate and changes in physico-chemical and sensory properties were investigated. No spoiled peaches were observed within the first four days of storage in the control and 2.5 kJ/㎡ UV-C treatment groups. However, spoilage was observed in these groups on day six, and 29.17% and 25.0% of the samples showed spoilage on 10 day, respectively. Moreover, samples treated with greater than 5.0 kJ/㎡ of UV-C showed a higher percentage (41.67% or higher) of spoilage than those of the control or 2.5 kJ/㎡ UV-C treatment groups on 10 day. Additionally, weight changes in the peaches were the lower in the control group and 2.5 kJ/㎡ UV-C treatment group than in those treated with 5.0 kJ/㎡ of UV-C treatment or higher during 10 days of storage. There was no difference in pH among treatments, regardless of storage time. The hardness of the samples was not changed immediately after UV-C treatment, but that of samples treated with 5.0~10.0 kJ/㎡ of UV-C decreased rapidly after four days, when compared to the control and 2.5 kJ/㎡ UV-C treatment groups. No significant changes in the lightness and redness of the samples were observed in response to UV-C treatment, however, UV-C treatment led to a slight decrease in the yellowness of the samples. The initial taste, flavor, color, texture, and overall acceptance did not differ among control and UV-C treatments. The sensory score of the samples was the highest after 2 and 4 days of storage, while it decreased thereafter. In general, samples in the control and the 2.5 kJ/㎡ UV-C treatment groups showed higher sensory quality than those treated with UV-C at 5.0 kJ/㎡ or higher.

Degradation mechanism of anatoxin-a in UV-C/H₂O₂ reaction

Tak, So-Yeon,Kim, Moon-Kyung,Lee, Jung-Eun,Lee, Young-Min,Zoh, Kyung-Duk Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.334 No.-

<P><B>Abstract</B></P> <P>In this study, the kinetics and removal mechanism of anatoxin-a (C<SUB>10</SUB>H<SUB>15</SUB>NO) during a UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction were investigated. The removal of anatoxin-a was more effective during a UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction than with either UV photolysis or H<SUB>2</SUB>O<SUB>2</SUB> alone, due to the effective production of hydroxyl (OH) radicals. The UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction of anatoxin-a resulted in an approximately 60% decrease in total organic carbon (TOC) within 420 min, while 45% of the carbon in anatoxin-a was converted into acetate, and most of the nitrogen in anatoxin-a was converted into NH<SUB>4</SUB> <SUP>+</SUP>, NO<SUB>2</SUB> <SUP>−</SUP>, and NO<SUB>3</SUB> <SUP>−</SUP> ions. More than 50% of the nitrogen in anatoxin-a was mineralized, mainly into NO<SUB>3</SUB> <SUP>−</SUP> ions, and complete nitrogen recovery was achieved after 120 min of the UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction. Using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), we identified six degradation by-products in the UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction ([M+H]<SUP>+</SUP> = 142, 127, 113, 132, 117, and 124, respectively), which were further degraded as the reaction continued. Using these by-products, we proposed a degradation pathway for anatoxin-a during the UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction. Our results indicate that anatoxin-a can be effectively removed by a UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction during water treatment processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Removal of anatoxin-a was effective during UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction. </LI> <LI> NH<SUB>4</SUB> <SUP>+</SUP>, NO<SUB>2</SUB> <SUP>−</SUP>, and NO<SUB>3</SUB> <SUP>−</SUP> ions were produced as nitrogen byproducts in UV/H<SUB>2</SUB>O<SUB>2</SUB> reaction. </LI> <LI> Acetate was produced as a carbon short chain byproduct from anatoxin-a. </LI> <LI> Six degradation byproducts during UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction were newly identified. </LI> <LI> The degradation pathway of anatoxin-a during UV-C/H<SUB>2</SUB>O<SUB>2</SUB> reaction was proposed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

복숭아 저장성 증진을 위한 저선량의 UV-C 조사 효과

이경행 ( Kyung Haeng Lee ),박재희 ( Jae Hee Park ),이유진 ( Yu Jin Lee ),반기은 ( Ki Eun Ban ),장주희 ( Joo Hee Jang ) 한국식품영양학회 2013 韓國食品營養學會誌 Vol.26 No.1

국내산 복숭아의 저장성 증진을 위하여 저선량(0∼3.0kJ/㎡)의 UV-C를 조사하고, 저장기간 동안 부패율, 이화학적 변화 및 기호도의 변화를 측정하였다. 부패율의 경우, 대조군은 4일 이후부터는 부패된 복숭아를 보이기 시작하였으며, 저장 8일에는 50.00%의 부패율을 나타내었다. 저선량의 UV-C 처리군은 대조군보다 낮은 부패율을 보였으며, 특히 1.0 및 2.0kJ/㎡의 UV-C 처리군이 가장 낮은 부패율을 나타내었다. 무게 변화의 경우, 대체적으로 대조군 및 UV-C 처리군 모두 저장기간 동안 큰 차이를 보이지는 않았다. pH 변화에서는 UV-C 처리에 의한 차이를 보이지 않았으며, 저장기간 중 pH가 증가하였으나 모든 실험군에서 차이가 없는 것으로 나타났다. 경도의 경우, UV-C 처리 직후에는 모든 실험군에서 차이가 없었으나, 저장 중 대조군의 변화가 가장 많았으며, UV-C 처리군의 경도 변화는 적은 것으로 나타났다. 색도 변화(명도, 적색도 및 황색도)에서는 UV-C 처리 및 저장 중 모든 실험군에서 큰 차이를 보이지는 않는 것으로 나타났다. 맛, 향, 색에 대한 기호도의 변화에서는 UV-C 처리에 의한 변화를 보이지 않았으며, 저장 중 기호도는 감소하였으나 모든 실험군에서 차이가 없는 것으로 나타났다. 조직감 및 종합적 기호도에서는 UV-C 처리에 의한 변화를 보이지 않았으나 저장 중 대조군의 기호도값이 가장 많이 감소하였고, UV-C 처리군의 변화는 적은 것으로 나타났다. 전반적으로 대조군보다는 저선량의 UV-C 처리군이 기호도가 높은 것으로 나타났다. For shelf-life improvement of the domestic peach, a treatment with low dose UV-C (0∼3.0kJ/㎡) irradiation was performed and the spoilage rate and changes of physico-chemical and sensory properties of the peach were investigated. Control showed spoilage at day 4, and then 50% of control showed spoilage at day 8. However, samples treated with low dose UV-C showed lower percentage of spoilage than those of control at day 8. Weight changes of control and the samples with UV-C treatment showed no difference during the storage period. There was no difference in pH of samples among the treatments but they were increased by storage time. Hardness of samples was not different among treatments at initial stage of storage after UV-C treatment. However, the hardness of control sample was decreased faster than those of the samples with low dose UV-C treatment after 6 days of storage. No significant changes in lightness, redness and yellowness of the samples by UV-C treatment were observed. The sensory parameters including taste, flavor, and color at initial and during storage period were not different among treatments except for texture and overall acceptance. The scores for texture and overall acceptance of control were decreased faster than those of UV-C treatments during storage. In general, samples treated with low dose UV-C showed higher sensory quality than control.

UV-C 조사에 의한 음용수 살균 시스템의 미생물 저해 효과

김현중(Hyun-Joong Kim),김윤재(Yun-Jae Kim),서세영(Se-Yeong Seo),이창주(Chang Joo Lee) 한국식품과학회 2021 한국식품과학회지 Vol.53 No.2

본 연구는 그람 음성균과 양성균인 E. coli와 L. monocytogenes를 인위적으로 오염시킨 음용수를 대상으로 UV-C 정수기의 살균 가능성과 미생물의 생육 저해에 따른 형태학적 특성을 조사하였다. UV-C를 이용한 음용수 살균 능력은 그람 음성균 E. coli와 양성균 L. monocytogenes의 저농도부터 고농도(E. coli 3.2×10³-3.2×10<SUP>7</SUP> CFU/2.8 L; L. monocytogenes 8.4×10³-8.4×10<SUP>7</SUP> CFU/2.8 L) 세균 모두의 생육을 저해할 수 있는 효과가 나타났다. 따라서 UV를 이용한 음용수 살균은 유속 3.4 L/min에서 UV-C 파장 254 nm, 조사선량 40 mJ/cm²로 조사할 경우 E. coli 3.2×10<SUP>7</SUP> CFU/2.8 L와 L. monocytogenes 8.4×10<SUP>7</SUP> CFU/2.8 L 이하 농도의 오염된 음용수의 살균이 가능한 것으로 나타났다. 정수기에 UV-C 살균장치를 추가하는 것이 물의 미생물 안전성에 효율적이라고 사료되며, 이 연구결과는 UV살균 장치 활용의 기초자료로 제공되어 향후 연구 수행에 도움을 줄 수 있을 것이다. This study aimed to investigate bacterial disinfection in drinking water using a water purifier. Water artificially inoculated with Escherichia coli and Listeria monocytogenes at various concentrations was irradiated using ultraviolet (UV)-C at a rate of 3.4 L/min in a water purifier, and the disinfection effects of UV-C were evaluated. Both E. coli and L. monocytogenes were disinfected up to 10<SUP>7</SUP> colony-forming units (CFU)/2.8 L by the UV-C irradiation. Additionally, morphological study using fluorescence microscopy in conjunction with live/dead staining revealed that both the bacteria species were disinfected by the UV-C irradiation. Therefore, UV-C in water purifiers can effectively kill high concentrations of bacteria in distilled water. UV irradiation (UV-C: 254 nm wavelength, irradiation dose: 40 mJ/cm²) at a flow rate of 3.4 L/min on drinking water has the potential to sterilize bacteria-contaminated drinking water, at least for 3.2×10<SUP>7</SUP> CFU/2.8 L of E. coli and 8.4×10<SUP>7</SUP> CFU/2.8 L of L. monocytogenes.

Inactivation of Salmonella Typhimurium and Escherichia coli O157:H7 on black pepper powder using UV-C, UV-A and TiO2 coating

박미정,김진희,오세욱 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.2

This study was conducted to measure the inactivation characteristics of UVs and TiO2 against Salmonella. Typhimurium and Escherichia coli O157:H7 on black pepper powder. The sample was irradiated by UV-A and UV-C combined with TiO2 coating. After treatment, microbial and physicochemical analysis was carried out. Among various sterilization conditions, the largest number of pathogen in black pepper powder was inactivated by UV-A and UV-C combined with TiO2 coating. The microbial count of black pepper powder treated simultaneously with UV-A and UV-C was less than that of black pepper powder treated with alone. The inactivation effect of UV-A and UV-C was increased when TiO2 coating was combined. Moisture content was decreased with increasing treatment time, but color did not change. In this study, it was indicated that the combined treatment of UV-C, UV-A and TiO2 coating was effective for reducing S. Typhimurium and E. coli O157:H7 on black pepper powder.

UV-C, 에탄올 처리가 신선편이(Fresh-cut) 씨 없는 수박의 품질에 미치는 영향

한현아,조승현,이송이,김은주,송은주 한국식품영양학회 2023 韓國食品營養學會誌 Vol.36 No.1

To apply UV-C as a non-heating sterilization method to increase the microbiological safety of fresh seedless watermelon products, reductions in E. coli and quality changes by treatment dose (0, 2, 4, 8, 14, 20 kJ/m2) were investigated. The pH, sugar content, and hardness of watermelon inoculated with E. coli were not significantly different according to the UV-C treatment dose, but the polyphenol content was significantly decreased compared to the controls (425.4 GAE μg/g F.W.). When treated with 2 and 4 kJ/m2, the lycopene content was 31.6 and 30.9 μg/g F.W., respectively, which was increased compared to the controls (28.5 μg/g F.W.). The arginine and citrulline content was also significantly increased compared to the controls. The number of E. coli was significantly decreased compared to the controls following UV-C treatment. Considering the degree of E. coli reduction, lycopene content, arginine content, citrulline content, and UV-C irradiation time, subsequent experiments were conducted by selecting a UV-C treatment dose of 2 kJ/m2. The results of confirming the degree of reduction in the number of E. coli colonies by a single treatment and combined treatment with UV-C 2 kJ/m2 and 70% ethanol showed that the combined treatment was most effective as colonies were decreased by 2.3 log CFU/g compared to the controls. Therefore, it is judged that UV-C 2 kJ/m2 radiation and combined treatment with 70% ethanol could be applied as a non-heating sterilization method for fresh watermelon slices.

이산화염소수, Ultraviolet-C 또는 병합처리가 샐러리와 체리에서의 살균 및 냉장저장 중 미생물 성장에 미치는 효과

송현정(Hyeon Jeong Song),천호현(Ho Hyun Chun),조완신(Wan Sin Jo),송경빈(Kyung Bin Song) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.3

신선편이 채소류 중 샐러리와 체리의 미생물학적 안전성을 확보하기 위해 50 ppm 이산화염소수와 10 kJ/㎡ 선량의 UV-C 조사와의 병합 처리에 따른 저장 중 미생물 수의 변화를 측정하였다. E. coli O157:H7로 접종된 샐러리와 체리의 경우, 이산화염소수와 UV-C 병합 처리구의 E. coli O157:H7 수가 대조구와 비교했을 때 각각 2.8, 3.0 log CFU/g의 감소효과를 나타냈다. 또한 접종하지 않은 샐러리와 체리의 총 호기성 균은 병합 처리로 각각 2.9, 1.8 log CFU/g이 감소되었고, 효모 및 곰팡이도 1.8, 1.2 log CFU/g의 감소효과를 나타냈다. 따라서 본 연구결과, 50 ppm 이산화염소수와 10 kJ/㎡ UV-C 조사의 병합처리가 샐러리와 체리의 저장 중 오염될 수 있는 위해미생물 수 감소에 있어서 효과적인 살균처리 기술이라고 판단된다. The effects of a combined treatment of aqueous chlorine dioxide (ClO₂) and ultraviolet-C (UV-C) irradiation on microbial growth in celery and cherries were investigated. Celery and cherry samples were treated with 50 ppm ClO₂, UV-C at dose of 10 kJ/㎡, and a combination of ClO₂ and UV-C. The changes in the counts of Escherichia coli O157:H7 inoculated in the celery and cherries as well as those of total aerobic bacteria, yeast and molds in the celery and cherries were investigated after each treatment. After the combined treatment of aqueous ClO₂ and UV-C irradiation, the populations of E. coli O157:H7 in the inoculated celery and cherries were reduced by 2.8 and 3.0 log CFU/g, respectively, compared to those of the control. For the un-inoculated celery and cherries, the populations of total aerobic bacteria were reduced by 2.9 and 1.8 log CFU/g, respectively, compared to the control. In addition, the populations of yeast and molds were decreased by 1.8 and 1.2 log CFU/g, respectively. These results suggest that the combined treatment of 50 ppm ClO₂ and UV-C at a dose of 10 kJ/㎡ would be an effective technology for decontamination and improving the microbiological safety in celery and cherries during chilled storage.

Effect of UV-C irradiation on the inactivation of inoculated pathogens and quality of chicken breasts during storage

Chun, H.H.,Kim, J.Y.,Lee, B.D.,Yu, D.J.,Song, K.B. Butterworths ; Taylor Francis ; Elsevier Science 2010 FOOD CONTROL Vol.21 No.3

In this study, we evaluated the inactivation of foodborne pathogens inoculated on chicken breasts by UV-C treatment. Chicken breasts were inoculated with Campylobacter jejuni, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium at 6-7logCFU/g. The inoculated chicken breasts were then irradiated with UV-C light of dose 0, 0.5, 1, 3, and 5kJ/m<SUP>2</SUP>. Microbiological data indicated that the populations of the foodborne pathogens decreased significantly (p<0.05) with increasing UV-C irradiation. In particular, UV-C irradiation at 5kJ/m<SUP>2</SUP> reduced the initial populations of C. jejuni, L. monocytogenes, and S. typhimurium by 1.26, 1.29, and 1.19logCFU/g, respectively. After UV-C irradiation, the samples were individually packed using polyethylene terephthalate containers and stored at 4+/-1<SUP>o</SUP>C for 6 d. The pH of the control increased more than the samples irradiated at 0.5, 1, 3, and 5kJ/m<SUP>2</SUP>, while TBARS values increased during storage regardless of UV-C irradiation. UV-C irradiation caused negligible changes in Hunter L, a, and b values. These results suggest that UV-C irradiation can be useful in improving the microbial safety of chicken breasts during storage, without impairing quality.

살균조건 및 UV-C 조사가 느타리버섯 병재배 오염율 감소에 미치는 영향

백일선,지정현,정윤경,김정한,임재욱 한국버섯학회 2015 한국버섯학회지 Vol.13 No.3

This study was conducted to reduce contamination ratio of oyster mushroom bottle cultivation. The optimal conditions of substrate sterilization for reducing of contamination ratio were at 121oC for 90 min. In addition, UV-C irradiation is good for lower contamination ratio to continue over 6 hours at cooling and inoculation room after sterilization. The contamination ratio and density of microorganisms of substrate were showed 0% after sterilization at 121oC for 90 min. Trichoderma sp., main pathogen of mushrooms, was detected from substrate after sterilized during 2 or 4 hours at 101oC and 105oC, respectively. The amount of electricity used was the lowest at 121oC for 90 min than that of other sterilization conditions. The UV-C irradiation treatment was used UV-C lamp(40 watts) in the inoculation room(56 m 3 ). The density of bacteria did not detected after UVC irradiation for 6 hours. And the death ratio of bacteria and Trichoderma sp. was 99.9% after UV-C irradiation for 6 hours. However, in the same UV-C irradiation time, the death ration of Cladosporium sp. was 90.9%. Therefore, the death ratio of fungi was lower than that of bacteria at the same UV-C irradiation treatment.

살균조건 및 UV-C 조사가 느타리버섯 병재배 오염율 감소에 미치는 영향

백일선,지정현,정윤경,김정한,임재욱 한국버섯학회 2015 한국버섯학회지 Vol.13 No.3

This study was conducted to reduce contamination ratio of oyster mushroom bottle cultivation. The optimalconditions of substrate sterilization for reducing of contamination ratio were at 121oC for 90min. In addition, UV-C irradiation isgood for lower contamination ratio to continue over 6 hours at cooling and inoculation room after sterilization. Thecontamination ratio and density of microorganisms of substrate were showed 0% after sterilization at 121oC for 90min.Trichoderma sp., main pathogen of mushrooms, was detected from substrate after sterilized during 2 or 4 hours at 101oC and 105oC,respectively. The amount of electricity used was the lowest at 121oC for 90min than that of other sterilization conditions. The UV-Cirradiation treatment was used UV-C lamp(40 watts) in the inoculation room(56m3). The density of bacteria did not detected after UV-C irradiation for 6 hours. And the death ratio of bacteria and Trichoderma sp. was 99.9% after UV-C irradiation for 6 hours. However,in the same UV-C irradiation time, the death ration of Cladosporium sp. was 90.9%. Therefore, the death ratio of fungi was lower thanthat of bacteria at the same UV-C irradiation treatment.