Journal of Food Hygiene and Safety (한국식품위생안전성학회지)

The Korean Society of Food Hygiene and Safety (한국식품위생안전성학회)
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Efficacy of Sodium Hypochlorite against E. coli on Various Leafy Green and Stem Vegetables

차아염소산나트륨이 비가열 엽경채류 중 병원성 대장균 사멸에 미치는 영향

  • Su-jin Kim (Department of Food and Nutrition, Yeungnam University) ;
  • Woo-Suk Bang (Department of Food and Nutrition, Yeungnam University)
  • Received : 2022.11.05
  • Accepted : 2023.01.02
  • Published : 2023.02.28
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Abstract

This study was conducted to evaluate the efficacy of sodium hypochlorite in eliminating Escherichia coli strains from leafy green and stem vegetables, which are frequently sold at community service centers. A cocktail of non-pathogenic E. coli and enterohaemorrhagic E. coli (E. coli O157:H7) was used to artificially contaminate the vegetables (initial numbers of bacteria 7-8 log CFU/g). The contaminated vegetables were soaked in sodium hypochlorite for 5 min and then washed three times with running water. After the treatment, number of viable bacterial cells on the vegetables was estimated. Sodium hypochlorite treatment reduced the E. coli population by 1-2 log CFU/g on leafy green and stem vegetables, a significant reduction from the initial number. Further, sodium hypochlorite showed better antimicrobial efficacy for leaves with a larger surface area, less roughness, and softness. There was no significant difference in the antimicrobial effect between 100 and 200 mg/kg of sodium hypochlorite. Therefore, it is not necessary to increase sodium hypochlorite concentration than the level suggested in the school meal hygiene management guidelines. However, sodium hypochlorite treatment is not sufficient to achieve a safe level of microorganisms on leafy green and stem vegetables since they generally have a high abundance of microorganisms on their surface. Thus, an alternative cooking method for fresh leafy green and stem vegetables in summer should be developed to ensure they are safe for consumption.

본 연구는 집단급식소에서 제공되는 빈도수가 높은 비가열 및 가열조리 엽경채류에 사용되는 차아염소산나트륨 수에 대하여 미생물적 안전성을 평가하고자 수행되었다. 비병원성 대장균과 장출혈성 대장균의 칵테일(E. coli O157:H7)을 엽경채류(초기 균수 7-8 log CFU/g)에 인위적으로 오염시킨 후 차아염소산나트륨을 5분간 침지 후 흐르는 물에 3번 씻어서 생균수를 측정하였다. 실험 결과 초기 오염물질에 비해 살균효과가 1-2 log CFU/g 저감화하여 대조군에 대해 유의적인 차이가 있었다(P<0.05). 잎채소의 특성에 따라 약간의 차이가 있었는데 표면적이 클수록, 덜 거칠고 잎이 부드러울수록 살균효과가 높았다. 200 mg/kg으로 처리하였을 때 100 mg/kg에 비해 0.1-0.3 log CFU/g만큼 효과가 더 감소하였으나 농도 증가에 따른 유의적 차이는 없었다(P>0.05). 그러므로 학교급식위생관리지침에서 제시한 기준 이상으로 차아염소산나트륨 농도를 높이는 것은 불필요하다고 판단된다. 그러나 잎채소는 일반적으로 미생물의 초기 오염도가 높기 때문에 차아염소산나트륨 처리만으로는 안전한 수준의 저감을 달성하기 어려워 생물학적 위험이 잔존한다. 따라서 여름철에 가열하지 않은 잎채소의 대체 조리방법을 개발하는 것이 안전성에 보다 효과적인 것으로 판단된다.

Keywords

References

  1. Kim, Y.H., Jun, S.Y., Ryu, K., Lee, Y.K., Microbiological quality and safety during delivery of food ingredients supplied to elementary schools: vegetables and processed food. Korean J. Food Preserv., 17, 586-594 (2010). 
  2. Teixeira, P., Fernandes, B., Silva, A.M., Dias, N., Azeredo, J., Evaluation by flow cytometry of Escherichia coli viability in lettuce after disinfection. Antibiotics, 9, 14 (2020). 
  3. Hong, C.K., Seo, Y.H., Choi, C.M., Hwang, I.S., Kim, M.S., Microbial quality of fresh vegetables and fruits in Seoul, Korea. J. Food Hyg. Saf., 27, 24-29 (2012).  https://doi.org/10.13103/JFHS.2012.27.1.024
  4. Pezzuto, A., Belluco, S., Losasso, C., Patuzzi, I., Bordin, P., Piovesana, A., Comin, D., Mioni, R., Ricci, A., Effectiveness of washing procedures in reducing Salmonella enterica and Listeria monocytogenes on a raw leafy green vegetable (Eruca vesicaria). Front. Microbiol., 7, 1663 (2016). 
  5. Choi, S.Y., Chu, H.J., Rajalingam, N., Chae, H.B., Yoon, J.H., Hwang, I., Kim, S.R., Growth of Escherichia coli and Listeria monocytogenes on radish microgreens washed with sodium hypochlorite during storage. Korean J. Food Preserv., 27, 850-858 (2020).  https://doi.org/10.11002/kjfp.2020.27.7.850
  6. Carstens, C.K., Salazar, J.K., Darkoh, C., Multistate outbreaks of foodborne illness in the United States associated with fresh produce from 2010 to 2017. Front. Microbiol., 10, 2667 (2019). 
  7. Kim, S.R., Ryu, K.Y., Lee, M.H., Jung, C.S., Yoon, Y., Shim, W.B., Kim, J.H., Kim, B.S., Yoo, S.Y., Kim, D.H., Yun, J.C., Chung, D.H., Evaluation of the bactericidal activity of electrolyzed water against Salmonella Typhimurium and Staphylococcus aureus on perilla leaves. Korean J. Food Sci. Technol., 44, 467-471 (2012).  https://doi.org/10.9721/KJFST.2012.44.4.467
  8. Yun, B., Lee, H.S., An, H.M., Kim, W.I., Kim, H.Y., Han, S., Kim, H.J., Ryu, J.G., Kim, S.R., Effect of chlorine dioxide and sodium hypochlorite treatment on the reduction of food-borne pathogen in Korean chive. J. Food Hyg. Saf., 32, 154-162 (2017).  https://doi.org/10.13103/JFHS.2017.32.2.154
  9. Min, J.H., Nam, G.W., Yoon, K.S., Effect of sanitization on risk reduction of Staphylococcus aureus and pathogenic Escherichia coli on leaf and stem vegetables. Korean J. Food Cook. Sci., 33, 708-712 (2017).  https://doi.org/10.9724/kfcs.2017.33.6.708
  10. Bae, Y.M., Hong, Y.J., Kang, D.H., Heu, S., Lee, S.Y., Microbial and pathogenic contamination of ready-to-eat fresh vegetables in Korea. Korean J. Food Sci. Technol., 43, 161-168 (2011).  https://doi.org/10.9721/KJFST.2011.43.2.161
  11. Park, S.G., Choi, Y.D., Lee, C.W., Jeong, M.J., Kim, J.S., Chung, D.H., Shim, W.B., Investigation of microbiological hazard from Korean leeks and cultivation area to establish the GAP model. J. Food Hyg. Saf., 30, 28-34 (2015).  https://doi.org/10.13103/JFHS.2015.30.1.28
  12. Prado-Silva, L., Cadavez, V., Gonzales-Barron, U., Rezende, A.C., Sant'Ana, A.S., Meta-analysis of the effects of sanitizing treatments on Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes inactivation in fresh produce. Appl. Environ. Microbiol., 81, 8008-8021 (2015).  https://doi.org/10.1128/AEM.02216-15
  13. MFDA, 2020. Additives Code. Ministry of Food and Drug Safety, Cheongju, Korea. 
  14. U.S. Food Drug Administration, FDA News, FDA finalizes report on 2006 spinach outbreak. Retrieved from http://www.fda.gov/bbs/topics/NEWS/2007/NEW01593.html 
  15. Ministry of Education., School food service hygienic management guideline. (5th). Retrieved from https://www.gne.go.kr/upload_data/board_data/BBS_0000053/161637419893082.pdf 
  16. Fransisca, L., Feng, H., Effect of surface roughness on inactivation of Escherichia coli O157:H7 87-23 by new organic acid-surfactant combinations on alfalfa, broccoli, and radish seeds. J. Food Prot., 75, 261-269 (2012).  https://doi.org/10.4315/0362-028X.JFP-11-279
  17. Lee, H.H., Hong, S.I., Kim, D., Microbial reduction efficacy of various disinfection treatments on fresh-cut cabbage. Food Sci. Nutr., 2, 585-590 (2014).  https://doi.org/10.1002/fsn3.138
  18. Wang, H., Feng, H., Liang, W., Luo, Y., Malyarchuk, V., Effect of surface roughness on retention and removal of Escherichia coli O157:H7 on surfaces of selected fruits. J. Food Sci., 74, E8-E15 (2009).  https://doi.org/10.1111/j.1750-3841.2008.00998.x
  19. Abadias, M., Usall, J., Oliveira, M., Alegre, I., Vinas, I., Efficacy of neutral electrolyzed water (NEW) for reducing microbial contamination on minimally-processed vegetables. Int. J. Food Microbiol., 123, 151-158 (2008).  https://doi.org/10.1016/j.ijfoodmicro.2007.12.008
  20. Norwood, D.E., Gilmour, A., The growth and resistance to sodium hypochlorite of Listeria monocytogenes in a steady-state multispecies biofilm. J. Appl. Microbiol., 88, 512-520 (2000).  https://doi.org/10.1046/j.1365-2672.2000.00990.x
  21. Cha, H.S., Kim, S., Kim, B.S., Kim, S.H., Park, S.J., Cho, H.S., Choi, H.Y., Effect of inhibition on browning and microbial growth of minimally processed lettuce. Korean J. Food Preser., 11, 331-335 (2004). 
  22. Jin, Y., Kim, T.W., Ding, T., Oh, D.H., Effect of electrolyzed water and citric acid on quality enhancement and microbial inhibition in head lettuce. Korean J. Food Sci. Technol., 41, 578-586 (2009). 
  23. Park, S.S., Sung, J.M., Jeong, J.W., Park, K.J., Lim, J.H., Efficacy of electrolyzed water and aqueous chlorine dioxide for reducing pathogenic microorganism on Chinese cabbage, Korean J. Food Sci. Technol., 44, 240-246 (2012).  https://doi.org/10.9721/KJFST.2012.44.2.240
  24. Lee, H.H., Hong, S.I., Kim, D., Microbial reduction efficacy of various disinfection treatments on fresh-cut cabbage. Food Sci. Nutr., 2, 585-590 (2014).  https://doi.org/10.1002/fsn3.138
  25. Choi, J.W., Park, S.Y., Yeon, J.H., Lee, M.J., Chung, D.H., Lee, K.H., Kim, M.G., Lee, D.H., Kim, K.S., Ha, S.D., Microbial contamination levels of fresh vegetables distributed in markets. J. Food Hyg. Saf., 20, 43-47 (2005). 
  26. Lee, W.J., Lee, C.H., Yoo, J.Y., Kim, K.Y., Jan, K.I., Sterilization efficacy of washing method using based on microbubbles and electrolyzed water on various vegetable. J. Korean Soc. Food Sci. Nutr., 40, 912-917 (2011).  https://doi.org/10.3746/jkfn.2011.40.6.912
  27. Mahmoud, B.S., The effects of X-ray radiation on Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri inoculated on whole roma tomatoes. Food Microbiol., 27, 1057-1063 (2010).  https://doi.org/10.1016/j.fm.2010.07.009
  28. Kocharunchitt, C., Ross, T., McNeil, D.L., Use of bacteriophages as biocontrol agents to control Salmonella associated with seed sprouts. Int. J. Food Microbiol., 128, 453-459 (2009).  https://doi.org/10.1016/j.ijfoodmicro.2008.10.014
  29. Alvaro, J.E., Moreno, S., Dianez, F., Santos, M., Carrasco, G., Urrestarazu, M., Effects of peracetic acid disinfectant on the postharvest of some fresh vegetables. J. Food Eng., 95, 11-15 (2009). https://doi.org/10.1016/j.jfoodeng.2009.05.003