Fate of Listeria monocytogenes in Ready-to-Eat Turkey Breast Rolls Formulated with Antimicrobials Following E-Beam Irradiation

Abstract

The objective of this study was to determine the effect of antimicrobials on the survival and proliferation of L. monocytogenes in turkey breast rolls following electronbeam 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% potassum benzoate, 2% sodium lactate and 0.1% sodium diacetate (PB+SL+SDA) were used. Sliced turkey breast rolls were artificially inoculated with ~10 ⁶ CFU/cm ² five-strain- L. monocytogenes cocktails, then vacuum-packaged and irradiated at 0, 1.0, 1.5, 2.0 or 2.5 kGy. D10 values for breast rolls 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 two (PB+SL or SL+SDA) or three (PB+SL+SDA) antimicrobial combinations had 2 or 3 weeks 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 six weeks when stored at 4 °C. No growth of L. monocytogenes after irradiation occurred during 42 d 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 RTE 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 1.0kGy 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.