Microbiological Characterization and Chlorine Treatment of Buckwheat Sprouts

메밀 새싹채소의 주요 내재미생물 분석 및 염소처리에 따른 품질변화

  • Published : 2009.08.31

Abstract

In order to secure microbiological safety and quality of commercial vegetable sprouts, buckwheat seeds and sprouts were investigated for their microbiological flora and for the effect of chlorine treatment on quality. Microbiological analyses showed that major inherent bacteria including Enterobacter, Sphingomonas, and Klebsiella were found in commercial buckwheat sprouts with a population size ranging from $10^5$ to $10^7$ CFU/g. In addition, buckwheat seeds had a similar microbial flora to sprouts. Foodborne pathogenic bacteria such as Escherichia coli O157:H7, Staphylococcus aureus, Salmonella Typhimurium, and Listeria monocytogenes were not detected in the sprout or in the seed samples. Chlorine treatment with 50-150 ppm sodium hypochlorite noticeably reduced viable bacteria cell counts of the sprouts by about 1 log. However, no significant difference was observed among the different chlorine concentrations. After storage for 7 days at $5^{\circ}C$, the sprouts treated with 100-150 ppm chlorine showed higher sensory scores in visual quality than the others (p<0.05). The results indicated that proper pretreatment, such as dipping in chlorinated water, could confer a beneficial effect on the microbiological safety and visual quality of buckwheat sprouts.

친환경 기능성 채소로서 시장수요가 증가하고 있는 고품질 새싹채소의 수확 후 미생물 안전관리와 품질유지 유통기술을 개발하고자 메밀 새싹의 내재미생물을 검지하고 살균소독제로서 차아염소산나트륨의 적용 농도별 미생물 억제효과를 살펴보았다. 그 결과, 메밀 새싹의 주요 내재미생물 균총은 Enterobacter, Sphingomonas, Klebsiella 등이 대부분으로 $10^5-10^7$ CFU/g 수준이었으며, 그 종류는 종자 자체의 내재미생물과 유사하였고, E. coli O157:H7, Sal. Typhimurium, L. monocytogenes 등의 병원균은 검출되지 않았다. 50-150 ppm의 차아염소산염 용액으로 처리한 메밀 새싹의 생균수는 무처리구에 비해 약 1 log cycle 이상 감소하였으나 적용농도에 따른 차이는 유의적이지 않았다. 저온저장 7일 후 관능평가에서 100 ppm 이상의 염소수처리 새싹이 상대적으로 우수하게 평가되어 적정 농도의 염소수처리가 메밀 새싹채소의 미생물 억제 및 외관품질 유지에 긍정적인 효과를 나타내는 것으로 확인되었다.

Keywords

References

  1. Robertson LJ, Johannessen GS, Gjerde BK, Loncarevic SL. Microbiological analysis of seed sprouts in Norway. Int. J. Food Microbiol. 75: 119-126 (2002) https://doi.org/10.1016/S0168-1605(01)00738-3
  2. Kim YJ, Park HT, Han HS. A study on the production and marketing of sprouts and leaf vegetables. Research Report of Korea Rural Economic Institute (C2006-26), Suwon, Korea. pp. 84-87 (2006)
  3. Mead PS, Slutsker L, Dietz V. Food related illness and death in the United States. Emerg. Infect. Dis. 5: 607-625 (1999) https://doi.org/10.3201/eid0505.990502
  4. Taormina PJ, Beuchat LR, Slutsker L. Infections associated with eating seed sprouts: and international concern. Emerg. Infect. Dis. 5: 626-634 (1999) https://doi.org/10.3201/eid0505.990503
  5. NACMCF (National Advisory Committee on Microbiological Criteria for Foods). Microbiological safety evaluations and recommendations on sprouted seeds. Int. J. Food Microbiol. 52: 123-153 (1999) https://doi.org/10.1016/S0168-1605(99)00135-X
  6. Andrew WH, Mislivec PB, Wilson CR, Bruce VR, Poelma PL, Gibson R, Trucksess MW, Young K. Microbial hazards associated with bean sprouting. J. Assoc. Off. Anal. Chem. 65: 241-248 (1982)
  7. Jaquette CB, Beuchat LR, Mahon BE. Efficacy of chlorine and heat treatment in killing Salmonella stanley inoculated onto alfalfa seeds and storage. Appl. Environ. Microbiol. 62: 2212-2215 (1996)
  8. Stewart D, Reineke K, Ulaszek J, Fu T, Tortorello M. Growth of Escherichia coli O157:H7 during sprouting of alfalfa seeds. Lett. Appl. Microbiol. 33: 95-99 (2001) https://doi.org/10.1046/j.1472-765x.2001.00957.x
  9. FDA. Reducing microbial food safety hazards for sprouted seeds. Available from: http://vm.cfsan.fda.gov/~dms/sprougd1.html. Accessed on Feb. 8, 2009.
  10. Taormina PJ, Beuchat LR. Behavior of enterohemorrhagic Escherichia coli O157:H7 on alfalfa sprouts during the sprouting process as influenced by treatments with various chemicals. J. Food Prot. 62: 850-856 (1999)
  11. Fett WF. Reduction of the native microflora on alfalfa sprouts during propagation by addition of antimicrobial compounds to the irrigation water. Int. J. Food Microbiol. 72: 13-18 (2002) https://doi.org/10.1016/S0168-1605(01)00730-9
  12. Kim SL, Kim SK, Park CH. Introduction and nutritional evaluation of buckwheat sprouts as a new vegetable. Food Res. Int. 37: 319-327 (2004) https://doi.org/10.1016/j.foodres.2003.12.008
  13. Lee EY. Studies on biological activities of buckwheat sprout. MS thesis, Gangwon National University, Chuncheon, Korea (2003)
  14. Lin LY, Peng CC, Yang YL, Peng RY. Optimization of bioactive compounds in buckwheat sprouts and their effect on blood cholesterol in hamsters. J. Agr. Food Chem. 56: 1216-1223 (2008) https://doi.org/10.1021/jf072886x
  15. Kim YS, Kim JG, Lee YS, Kang IJ. Comparison of the chemical components of buckwheat seed and sprout. J Korean Soc. Food Sci. Nutr. 34: 81-86 (2005) https://doi.org/10.3746/jkfn.2005.34.1.081
  16. APHA. Standard methods for the examination of water and wastewater. 19th ed. 28. Iodometric Method I. American Public Health Association, Washington, DC, USA (1995)
  17. Spittstoesser DF, Queale DT, Andaloro BW. The microbiology of vegetable sprouts during commercial production. J. Food Saf. 5: 79-86 (1983) https://doi.org/10.1111/j.1745-4565.1983.tb00458.x
  18. Soylemez G, Brashears MM, Smith DA, Cuppett SL. Microbial quality of alfalfa seeds and sprouts after chlorine treatment and packaging modifications. J. Food Sci. 66: 153-357 (2001) https://doi.org/10.1111/j.1365-2621.2001.tb15598.x
  19. Patterson JE, Woodburn MJ. Klebsiella and other bacteria on alfalfa and bean sprouts at the retail level. J. Food Sci. 45: 492-495 (1980) https://doi.org/10.1111/j.1365-2621.1980.tb04083.x
  20. Brown C, Seidler RJ. Potential pathogens in the environment: Klebsiella pneumoniae, a taxonomic and ecological enigma. Appl. Microbiol. 25: 900-904 (1973)
  21. Bagley ST, Seidler RJ. Significance of fecal coliform-positive Klebsiella. Appl. Environ. Microbiol. 33: 1141-1148 (1977)
  22. Buedette JH, Santos C. Enterobacter sakazakii brain abscess in the neonate: The important of neuroradiologic imaging. Pediatr. Radiol. 30: 33-34 (2000) https://doi.org/10.1007/s002470050009
  23. Taormina PJ, Beuchat LR. Comparison of chemical treatment to eliminate enterohemorrhagic Escherichia coli O157:H7 on alfalfa seeds. J. Food Prot. 62: 318-324 (1999)
  24. Costerton JW, Lewandowski Z, Caldwell DE, Korber DR, Lappin-Scott HM. Microbial biofilms. Annu. Rev. Microbiol. 49: 711-745 (1995) https://doi.org/10.1146/annurev.mi.49.100195.003431
  25. Kylen AM, McCready RM. Nutrients in seeds, and sprouts of alfalfa, lentils, mung beans and soybeans. J. Food Sci. 40: 1008-1009 (1975) https://doi.org/10.1111/j.1365-2621.1975.tb02254.x
  26. Kang KJ. Korean disinfectants/sanitizers for food safety. Food Sci. Indus. 38: 99-106 (2005)
  27. Suslow T. Postharvest chlorination: Basic properties and key points for effective disinfection. Available from: http://danrcs. ucdavis.edu. Accessed on Feb. 2, 2009.
  28. Kim JK. Safety technology for fresh-cut fruits and vegetables. Food Preserv. Proc. Ind. 4: 18-25 (2005)