Radiation (gamma) resistance and postirradiation growth of Listeria monocytogenes suspended in beef bologna containing sodium diacetate and potassium lactate.
Listeria monocytogenes, a psychrotrophic foodborne pathogen, is a frequent postprocessing contaminant of ready-to-eat (RTE) meat products, including frankfurters and bologna. Ionizing radiation can eliminate L. monocytogenes from RTE meats. When they are incorporated into fine-emulsion sausages, sodium diacetate (SDA) and potassium lactate (PL) mixtures inhibit the growth of L. monocytogenes. The radiation resistance of L. monocytogenes, and its ability to proliferate during long-term refrigerated storage (9 degrees C), when inoculated into beef bologna that contained 0% SDA-0% PL, 0.07% SDA-1% PL, and 0.15% SDA-2% PL, were determined. The radiation doses required to eliminate 90% of the viable L. monocytogenes cells were 0.56 kGy for bologna containing 0% SDA-0% PL, 0.53 kGy for bologna containing 0.07% SDA-1% PL, and 0.46 kGy for bologna containing 0.15% SDA-2% PL. L. monocytogenes was able to proliferate on bologna containing 0% SDA-0% PL during refrigerated storage, but the onset of proliferation was delayed by the addition of the SDA-PL mixtures. An ionizing radiation dose of 3.0 kGy prevented the proliferation of L. monocytogenes and background microflora in bologna containing 0.07% SDA-1% PL and in bologna containing 0.15% SDA-2% PL over 8 weeks of storage at 9 degrees C. Little effect on lipid oxidation and color of the control bologna, or bologna containing SDA-PL mixtures, was observed upon irradiation at either 1.5 or 3.0 kGy.
Sommers
Christopher
C
U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Food Safety Intervention Technologies Research Unit, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. csommers@arserrc.gov
Fan
Xuetong
X
Niemira
Brendan A
BA
Sokorai
Kimberly
K
D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005514:Food Irradiation; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D005720:Gamma Rays; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D008461:Meat Products / Q000382:microbiology*; D019346:Sodium Acetate / Q000494:pharmacology*; D019354:Sodium Lactate / Q000494:pharmacology*
D019346:Sodium Acetate; D019354:Sodium Lactate