title: Radiation sensitivity and postirradiation growth of foodborne pathogens on a ready-to-eat frankfurter on a roll product in the presence of modified atmosphere and antimicrobials.
abstract: Intervention technologies including ionizing radiation, antimicrobials, and modified atmospheres (MA) can be used to inhibit the growth of or inactivate foodborne pathogens on complex ready-to-eat foods such as sandwiches. However, the effect of these technologies when used in combination (the hurdle concept) on the survival of foodborne pathogens is unknown. The ability of ionizing radiation to inactivate Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus inoculated onto a frankfurter on a roll product containing the antimicrobials sodium diacetate and potassium lactate in the presence of an MA (100% N2, 50% N2 plus 50% CO2, or 100% CO2) was investigated. The radiation resistances (D10-values) of the foodborne pathogens were 0.43 to 0.47 kGy for E. coli O157:H7, 0.61 to 0.71 kGy for Salmonella, 0.53 to 0.57 for L. monocytogenes, and 0.56 to 0.60 for S. aureus. The MA had no effect on the radiation resistance of the pathogens. During a 2-week storage period under mild temperature abuse (10 degrees C), none of the pathogens were able to proliferate on the frankfurter on a roll product, regardless of the MA used. However, application of sublethal doses of ionizing radiation resulted in increased mortality of the gram-positive pathogens L. monocytogenes and S. aureus during the storage period regardless of the MA. Although the pathogens were unable to proliferate on the frankfurter on a roll product during the storage period, application of a postpackaging intervention step was needed to actually inactivate the foodborne pathogens. Ionizing radiation used in combination with sodium diacetate and potassium lactate resulted in additional mortality of L. monocytogenes and S. aureus, independent of the MA, during the 2-week storage period.
authors.affiliation: Food Safety Intervention Technologies Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. csommers@errc.ars.usda.gov
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Sommers
authors.forename: Glenn
authors.initials: G
authors.lastname: Boyd
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004307:Dose-Response Relationship, Radiation; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D005506:Food Contamination / Q000517:prevention & control; D005514:Food Irradiation / Q000379:methods*; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology*; D005720:Gamma Rays; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D008461:Meat Products / Q000382:microbiology*; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012475:Salmonella / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D013696:Temperature; D013997:Time Factors
chemical_list: D005520:Food Preservatives; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen