title: Fate of Listeria monocytogenes in ready-to-eat turkey breast rolls formulated with antimicrobials following electron-beam irradiation.
abstract: The objective of this study was to determine the effect of antimicrobials on the survival and proliferation of Listeria monocytogenes in turkey breast rolls following electron-beam irradiation. Six antimicrobial additive treatments that include no preservatives (control), 0.1% potassium benzoate (PB), 2% sodium lactate (SL), 0.1% potassium benzoate plus 2% sodium lactate (PB + SL), 2% sodium lactate plus 0.1% sodium diacetate (SL + SDA), and 0.1% potassium benzoate, 2% sodium lactate, and 0.1% sodium diacetate (PB + SL + SDA) were used. Sliced turkey breast rolls were artificially inoculated with approximately 10(6) cfu/cm(2) of 5-strain L. monocytogenes cocktails, then vacuum-packaged and irradiated at 0, 1.0, 1.5, 2.0, or 2.5 kGy. The radiation dose (kGy) that results in 90% reduction of viable cells for breast rolls, D(10) value, with various additive treatments ranged from 0.56 to 0.58 kGy. Adding PB (0.1%) or SL (2%) in turkey rolls failed to prevent L. monocytogenes from growing during refrigerated storage. In turkey rolls added with 2 (PB + SL or SL + SDA) or 3 (PB + SL + SDA) antimicrobial combinations had 2 or 3 wk of lag phases before L. monocytogenes growth, respectively. Irradiating turkey rolls, which were added with PB + SL or SL + SDA, at 1.0 kGy was effective in suppressing the growth of L. monocytogenes for about 6 wk when stored at 4 degrees C. No growth of L. monocytogenes after irradiation occurred during 42 d of storage for 2.0 kGy irradiated breast rolls formulated with 0.1% PB + 2% SL, 2% SL + 0.1% SDA or 0.1% PB + 2% SL + 0.1% SDA, and 1.0 kGy irradiated turkey breast with 0.1% PB + 2% SL + 0.1% SDA. Sensory panelists found that low-dose irradiation (1.0 kGy) had no effect on the sensory characteristics of ready-to-eat turkey breast rolls. Including SL + SDA had slightly negative effect for nonirradiated turkey breast rolls, but the sensory characteristics of 1.0 kGy irradiated turkey roll containing SL + SDA was not significantly different from the others receiving 1.0 kGy irradiation. For microbial safety, PB + SL and SL + SDA antimicrobial treatments combined with 1.0 kGy or 2.0 kGy irradiation are a promising technology.
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50011-3150, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Zhu
authors.forename: A
authors.initials: A
authors.lastname: Mendonca
authors.forename: H A
authors.initials: HA
authors.lastname: Ismail
authors.forename: D U
authors.initials: DU
authors.lastname: Ahn
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005514:Food Irradiation / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D005520:Food Preservatives / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000528:radiation effects*; D008460:Meat / Q000382:microbiology*; D013997:Time Factors; D014422:Turkeys
chemical_list: D005520:Food Preservatives