Effect of Gamma Irradiation on the Microflora of Commercial Ready-To-Use (RTU) Salads during Cold Storage

  • Kim, Jang-Ho (Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute) ;
  • Lee, Ju-Woon (Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute) ;
  • Lee, You-Seok (Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute) ;
  • Oh, Sang-Hee (Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute) ;
  • Byun, Myung-Woo (Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute)
  • 발행 : 2004.09.01


Since ready-to-use (RTU) products are not fully cooked, the shelf-life of the product is comparably short and the products are easily spoiled when contaminated with food-borne pathogens. Low-dose gamma irradiation of 0.5, 1, or 2 kGy effectively reduced the total aerobic bacterial counts in 2 Korean manufactured RTU products by 1.63 to 2.95 log CFU/g during cold storage. Irradiation at 2 kGy reduced the psychrotrophic bacterial counts in most of the samples to below the limit of detection (< log CFU/g). Irradiation at 0.5 kGy completely eliminated Escherichia coli from the commercial RTU samples.


  1. Christophe N, Carlin F. 1994. The microbiology of minimally processed fresh fruits and vegetables. Crit Rev Food Sci Nutr 34: 371-401
  2. Odumeru JA, Mitchell SJ, Alves DM, Lynch JA, Yee AJ, Wang SL, Styliadis S, Farber JM. 1997. Assessment of the microbiological quality of ready-to-use vegetables for the healthcare food services. J Food Prot 60: 945-960
  3. Schlech SF. 1996. Overview of listeriosis. Food Control 7: 183-186
  4. Sizmur K, Walker CW. 1988. Listeria in prepackaged salad. Lancet 331: 1167
  5. Steinbruegge EG, Maxcy RB, Liewen MB. 1988. Fate of Listeria monocytogenes on ready-to-serve lettuce. J Food Prot 51: 596-599
  6. Beuchat LR. 1996. Pathogenic microorganisms associated with fresh produce. J Food Prot 59: 204-216
  7. Adrews WH, Mislivec PB, Wilson CR, Bruce VR, Poelma PL, Gibson R, Truckcess MW, Young K. 1982. Microbial hazards associated with bean sprouting. J AOAC 65: 241- 248
  8. Fain AR. 1996. A review of the microbiological safety of fresh salads. Dairy Food Environ Sanit 16: 146-149
  9. Hurst WC, Schuler GA. 1992. Fresh produce processing an industry perspective. J Food Prot 55: 824-827
  10. Madden JM. 1992. Microbial pathogens in fresh produce the regulatory perspective. J Food Prot 55: 821-823
  11. Beuchat LR. 1998. Surface decontamination of fruits and vegetables eaten raw: a review. Food Safety Unit World Health Organization WHO/FSF/98. p 2
  12. Fan X, Niemira BA, Sokorai KJB. 2003. Use of ionizing radiation to improve sensory and microbial quality of fresh-cut green onion leaves. J Food Sci 68: 1478-1483
  13. Prakash A, Inthajak P, Huibregtse H, Caporaso F, Foley D. 2000. Effects of low-dose gamma irradiation and conventional treatments on shelf life and quality characteristics of diced celery. J Food Sci 65: 1070-1075
  14. Foley DM, Dufour A, Rodriguez L, Caporaso F, Prakash A. 2002. Reduction of Escherichia coli O157:H7 in shredded iceberg lettuce by chlorination and gamma irradiation. Radiat Phys Chem 63: 391-396
  15. Prakash A, Manley J, DeCosta S, Caporaso F, Foley D. 2002. The effect of gamma irradiation on the microbiological, physical and sensory qualities of diced tomatoes. Radiat Phys Chem 63: 387-390
  16. Kamat A, Pingulkar K, Bhushan B, Gholap A, Thomas P. 2003. Potential application of low dose gamma irradiation to improve the microbiological safety of fresh coriander leaves. Food Control 14: 529-537
  17. Hagenmaier RD, Baker RA. 1997. Low-dose irradiation of cut iceberglettuce in modified atmosphere packaging. J Agric Food Chem 45: 2864-2868
  18. Hagenmaier RD, Baker RA. 1998. Microbial population of shredded carrot in modified atmosphere packaging as related to irradiation treatment. J Food Sci 63: 162-164
  19. Kader AA, Lipton WJ, Morris LL. 1973. Systems for scoring quality of harvested lettuce. HortSci 8: 408-409
  20. SAS Institute, Inc. 1990. SAS User's Guide. Statistical analysis system institute, Cary, NC, USA
  21. Marchetti R, Casadei MA, Gruerzoni ME. 1992. Microbial population dynamics in ready-to-use vegetable salads. Ital J Food Sci 2: 97-108
  22. Magnuson JA, King AD, Torok T. 1990. Microflora of partially processed lettuce. Appl Environ Microbiol 56: 3851-3560
  23. Garcia-Gimeno RM, Zurera-Cosano G. 1997. Determination of ready-to-eat vegetable salad shelf-life. Int J Food Microbiol 36: 31-38
  24. Garg N, Curely J, Splittstoesser D. 1990. Effect of processing conditions on the microflora of fresh-cut vegetables. J Food Prot 33: 701-703
  25. Abdul-Raouf U, Beuchat L, Ammar M. 1993. Survival and growth of Escherichia coli O157:H7 on salad vegetables. Appl Environ Microbiol 59: 1999-2006
  26. Manvell P, Ackland M. 1986. Rapid detection of microbial growth in vegetable salads at chill and abuse temperatures. Food Microbiol 3: 59-65
  27. Lin C, Fernando S, Wei C. 1996. Occurrence of Listeria monocytogenes, Salmonella spp., Escherichia coli and Escherichia coli O157:H7 in vegetable salads. Food Control 7: 135-140

피인용 문헌

  1. Inactivation of foodborne pathogens in ready-to-eat salad using UV-C irradiation vol.19, pp.2, 2010,