Inhibition of Listeria monocytogenes on frankfurters by modified atmosphere packaging and antimicrobials

The objective of this study was to determine the effect of vacuum packaging and 100% CO₂ with and without sodium lactate (0%, 2.4%, 4.8%), sodium acetate (0%, 0.25%, 0.50%), and sodium diacetate (0%, 0.25%, 0.50%) on the inhibition of L. monocytogenes on turkey frankfurters. After 4 weeks at 4°C, the counts of L. monocytogenes did not increase in any treatment, including the control. The use of sodium lactate (4.8%), sodium acetate (0.5%), and sodium diacetate (0.5%) provided approximately a 0.5 log10 CFU/g decrease when compared to the control; however, there was not a significant (P > 0.05) difference between the control and the samples using sodium acetate (0.25%), sodium diacetate (0.25%), or sodium lactate (2.4%). There was also no significant difference between the samples packaged in 100% CO₂ or under vacuum (P > 0.05). After 4 weeks at 10°C, growth of L. monocytogenes was approximately 1-1.5 log lower on the frankfurters packaged in 100% CO₂ than those packaged in a vacuum atmosphere (P £ 0.001). Sodium acetate (0.5%) and sodium lactate (2.4%) in combination with a high CO₂ atmosphere prevented any increase in L. monocytogenes numbers for up to 4 weeks at 10°C. The use of sodium lactate (4.8%) and sodium diacetate (0.5%) in combination with a high CO₂ atmosphere resulted in a decrease in numbers of L. monocytogenes on the frankfurters by ~0.5 log (P £ 0.001). Strict temperature control is needed to prevent the growth of L. monocytogenes. A high CO₂ atmosphere in combination with antimicrobials may assist in keeping the numbers of the organism in the food low in the case of product contamination and temperature abuse.