Improving the Food Safety of Seed Sprouts Through Irradiation Treatment

  • Waje, Catherine (Department of Food Science and Technology, Kyungpook National University) ;
  • Kwon, Joong-Ho (Department of Food Science and Technology, Kyungpook National University)
  • Published : 2007.04.30


Fresh sprouts such as alfalfa, mung bean, radish, broccoli, and soybean sprouts have become very popular due do their high nutritional value. However, there have been several outbreaks of illness in the last few years that have been attributed to sprout consumption. A number of methods have been used to improve the safety of seed sprouts. One promising technology is the use of ionizing radiation treatment. Irradiation with doses up to 8 kGy has been approved in the USA to control microbial pathogens in seeds intended for sprout production. This review focuses on the potential use of ionizing radiation in reducing the pathogen levels in seed sprouts. The effects of irradiation on seed germination and the nutritional quality of the sprouts are discussed.


  1. Kurtzweil P. Questions keep sprouting about sprouts. FDA Consum. 33: 18-22 (1999)
  2. Montville R, Schaffner D. Monte Carlo simulation of pathogen behavior during the sprout production process. Appl. Environ. Microb. 71: 746-753 (2005)
  3. National Advisory Committee on Microbiological Criteria for Foods. Microbiological safety evaluations and recommendations on sprouted seeds. Int. J. Food Microbiol. 52: 123-153 (1999)
  4. Schoeller NP, Ingham SC, Ingham BH. Assessment of the potential for Listeria monocytogenes survival and growth during alfalfa sprout production and use of ionizing radiation as a potential intervention treatment. J. Food Protect. 65: 1259-1266 (2002)
  5. Stewart DS, Reineke KF, Ulaszek JM, Tortorello ML. Growth of Salmonella during sprouting of alfalfa seeds associated with Salmonellosis outbreaks. J. Food Protect. 64: 618-622 (2001)
  6. Taormina PJ, Beuchat LR, Slutsker L. Infections associated with eating seed sprouts: an international concern. Emerg. Infect. Dis. 5: 626-634 (1999)
  7. Toumas VH. Moulds and yeasts in fresh and minimally processed vegetables, and sprouts. Int. J. Food Microbiol. 99: 71-77 (2005)
  8. Weagant SD, Bound AJ. Evaluation techniques for enrichment and isolation of Escherichia coli O157:H7 from artificially contaminated sprouts. Int. J. Food Microbiol. 71: 87-92 (2001)
  9. Jacquette CB, Beuchat LR, Mahon BE. Efficacy of chlorine and heat treatment in killing Salmonella stanley inoculated on alfalfa seeds and growth and survival of the pathogen during sprouting and storage. Appl. Environ. Microb. 62: 2212-2215 (1996)
  10. Beuchat LR. Comparison of chemical treatments to kill Salmonella on alfalfa seeds destined for sprout production. Int. J. Food Microbiol. 34: 329-333 (1997)
  11. Pierre PM, Ryser ET. Inactivation of Esherichia coli O157:H7, Salmonella typhimurium, Listeria monocytogenes on inoculated alfalfa seeds with fatty acid-based sanitizer. J. Food Protect. 69: 582-590 (2006)
  12. Bari ML, AI-Haq MI, Kwasaki T, Nakauma M, Todoriki S, Kwamoto S, Isshiki K. Irradiation to kill Escherichia coli O157:H7 and Salmonella on ready-to-eat radish and mungbean sprouts. J. Food Protect. 67: 2263-2268 (2004)
  13. Rajkowski KT, Thayer DW. Alfalfa seed germination and yield ratio and alfalfa sprout microbial keeping quality following irradiation of seeds and sprouts. J. Food Protect. 64: 1988-1995 (2001)
  14. Thompson S, Powell DA. Risks associated with the consumption of fresh sprouts. Available from: Accessed Mar. 23, 2006
  15. Rajkowski KT, Thayer DW. Reduction of Salmonella spp. and strains of Escherichia coli O157:H7 by gamma irradiation of inoculated sprouts. J. Food Protect. 63: 871-875 (2000)
  16. Fan X, Sokorai K, Sommers C, Niemira B, Mattheis, J. Effects of calcium carbonate, an antioxidant and anti browning agent, on radiation resistance of Listeria monocytogenes and the quality of Gala apple slices. p. 36E-31. In: IFT Annual Meeting. July 15-20, New Orleans, LA. Institute of Food Technologists, Chicago, IL, USA (2005)
  17. Hu H, Churey JJ, Worobo Rw. Heat treatments to enhance the safety of mung bean seeds. J. Food Protect. 67: 1257-1260 (2004)
  18. Thayer DW, Rajkowski KT. Developments in irradiation of fresh fruits and vegetables. Food Technol.-Chicago 53: 62-65 (1999)
  19. Thayer DW, Rajkowski KT, Boyd G, Cooke PH, Soroka DS. Inactivation of Escherichia coli O157:H7 and Salmonella by gamma irradiation of alfalfa seed intended for production of food sprouts. J. Food Protect. 66: 175-181 (2003)
  20. Sommers C, Handel A, Niemira B. Radiation resistance of Listeria monocytogenes in the presence and absence of sodium erythorbate. J. Food Sci. 62: 2266-2270 (2002)
  21. Hayashi T, Takahashi Y, Todoriki S. Sterilization of foods with low-energy electrons ('soft electrons'). Radiat. Phys. Chem. 52: 73-76 (1998)
  22. Lang MM, Ingham BH, Ingham SC. Efficacy of novel organic acid and hypochlorite treatments for eliminating . Escherichia coli O157:H7 from alfalfa seeds prior to sprouting. Int. J. Food Microbiol. 58: 73-82 (2000)
  23. Weissinger WR, Beuchat LR. Comparison of aqueous chemical treatments to eliminate Salmonella on alfalfa seeds. J. Food Protect. 63: 1475-1482 (2000)
  24. Robertson LJ, Johannessen GS, Gjerde BK, Loncarevic S. Microbiological analysis of seed sprouts in Norway. Int. J. Food Microbiol. 75: 119-126 (2002)
  25. Rajkowski KT, Fan X. Ionizing radiation of seeds and sprouts: a review: irradiated seeds and sprouts. pp. 107-116. In: Irradiation of Food and Packaging: Recent Developments. Komolprasert V, Morehouse KM (eds). Oxford University Press, New York, NY, USA (2004)
  26. Australian Food Safety Centre. Sprouted seeds and salmonellosis. Available from: Accessed Dec. 6, 2006
  27. Sharma RR, Demirci A. Treatment of Escherichia coli O157:H7 inoculated alfalfa seeds and sprouts with electrolyzed oxidizing water. lnt. J. Food Microbiol. 86: 231-237 (2003)
  28. Gandhi M, Matthews KR. Efficacy of chlorine and calcinated calcium treatment of alfalfa seeds and sprouts to eliminate Salmonella. lnt. J. Food Microbiol. 87: 301-306 (2003)
  29. Fan X, Thayer DW. Quality of irradiated alfalfa sprouts. J. Food Protect. 64: 1574-578 (2001)
  30. Thayer DW, Boyd G, Fett WF. Gamma irradiation decontamination of alfalfa seeds naturally contaminated with Salmonella mbandaka. J. Food Sci. 68: 1777-1781 (2003)
  31. Michino H, Araki K, Minami S, Takaya S, Sakai N, Miyazaki M, Ono A, Yanagawa H. Massive outbreak of Escherichia coli O157:H7 infection in schoolchildren in Sakai City, Japan, associated with consumption of white radish sprouts. Am. J. Epidemiol. 150: 787-796 (1999)
  32. Fan X, Rajkowski KT, Thayer DW. Quality of alfalfa sprouts grown from irradiated seeds. J. Food Quality 26: 165-176 (2003)
  33. Kwon H, Lee J, Kwon JH. Effects of electron-beam irradiation on microbiological and physicochemical qualities of powdered meju and soybean paste. Food Sci. Biotechnol. 10: 95-100 (2001)
  34. Himathongkham S, Nuanualsuwan S, Riemann H, Cliver DO. Reduction of Escherichia coli O157:H7 and Salmonella typhimurium in artificially contaminated alfalfa seeds and mung beans by fumigation of ammonia. J. Food Protect. 64: 1817-1819 (2001)
  35. Delaquis PJ, Sholberg PL, Stanich K. Disinfection of mungbean seed with gaseous acetic acid. J. Food Protect. 62: 953-957 (1999)
  36. International Consultative Group on Food Irradiation. Facts about food irradiation. Available from: foodirradiation.pdf. Accessed Nov. 6, 2006
  37. US Federal Register. 21 CFR 179. 65: 64605-64607 (2000)
  38. Wood M. Safer sprouts. Available from: Accessed Apr. 11, 2006
  39. Buck JW, Walcott RR, Beuchat LR. Recent trends in microbiological safety of fruits and vegetables. Plant Health Progress. Available from: Accessed Apr. 11, 2006
  40. Fett WF. Reduction of Escherichia coli O157:H7 and Salmonella spp. on laboratory-inoculated mungbean seed by chlorine treatment. J. Food. Protect. 65: 848-852 (2002)
  41. Suslow TV, Wu J, Fett WF, Harris LJ. Detection and elimination of Salmonella Mbandaka from naturally contaminated alfalfa seed by treatment with heat or calcium hypochlorite. J. Food Protect. 65: 452-458 (2002)
  42. Kausar T, K won JH, Kim HK. Comparative effect of gamma irradiation and fumigation on total phenol content and biological activities of different teas (Camellia sinensis). Food Sci. Biotechnol. 13: 671-675 (2004)
  43. National Advisory Committee on Microbiological Criteria for Foods. Microbiological safety evaluations and recommendations on fresh produce. Food Control 10: 117-143 (1999)
  44. Todoriki S, Kikuchi O, Nakaoka M, Miike M, Hayashi T. Soft electron (low energy electron) processing of foods for microbial control. Radiat. Phys. Chem. 63: 349-351 (2002)
  45. Harris LJ, Farber, JN, Beuchat LR, Parish ME, Suslow TV, Garret EH, Busta FF. Outbreaks associated with fresh produce: incidence, growth, and survival of pathogens in fresh and fresh-cut produce. Compr. Rev. Food Sci. F. 2: 78-141 (2003)
  46. Fan X, Thayer D, Sokorai KB. Changes in growth and antioxidant status of alfalfa sprouts during sprouting as affected by gamma irradiation of seeds. J. Food Protect. 67: 561-566 (2004)
  47. Rajkowski KT, Boyd G, Thayer DW. Irradiation D-values for Escherichia coli O157:H7 and Salmonella sp. on inoculated broccoli seeds and effects of irradiation on broccoli sprout keeping quality and seed viability. J. Food Protect. 66: 760-766 (2003)
  48. Food Safety Network. Sprout associated outbreaks in North America. Available from: Accessed Dec. 6, 2006
  49. Bari ML, Nazuka E, Sabina Y, Todoriki S, Isshiki K. Chemical and irradiation treatments for killing Escherichia coli O157:H7 on alfalfa, radish, and mungbean seeds. J. Food Protect. 66: 767-774 (2003)
  50. Brooks JT, Rowe SY, Shillam P, Heltzel DM, Hunter SB, Slutsker L, Hoekstra RM, Luby SP. Salmonella typhimurium infections transmitted by chlorine-pretreated clover sprout seeds. Am. J. Epidemiol. 154: 1020-1028 (2001)
  51. Lowe DS. Minimizing microbes on fresh-cut foods. Available from: Accessed Apr. 20, 2006