Purpose: The objectives of this study were to validate the inhibition of Listeria monocytogenes (Lm) on RTE, low sodium (1.4% sodium chloride), uncured turkey manufactured with different antimicrobial treatments and stored at 4°C for 12 weeks; and to determine the effect on sensory, color and cook loss.
Methods: Treatments tested were – an untreated control; 0.4%, 0.6% and 0.8% dry buffered vinegar; and 0.5%, 0.7% and 0.9% dry buffered vinegar-low sodium. The treatments were surface inoculated with a five strain mixture of Lm to provide approximately 5 log CFU per 100g package (equivalent to 3 log CFU per ml of rinse material when using 100 ml rinse for testing). Inoculated products were vacuum packaged and stored at 4°C for 12 weeks. Triplicate inoculated samples were tested for Lm growth by plating on modified Oxford agar and incubated at 37°C for 48 h. The study was conducted in three replications.
Results: Results showed that, dry vinegar at 0.6% and 0.8%, and dry vinegar-low sodium at 0.7% and 0.9%, significantly (P < 0.05) inhibited the growth of Lm compared with the untreated control by showing <1 log increase for 12 weeks. Untreated control showed >1 log and >3 log CFU/ml rinse by the end of 2 and 4 weeks, respectively. The 0.4% dry vinegar and 0.5% dry vinegar-low sodium showed >1 log increase at the end of 8 and 11 weeks, respectively. Cook loss, color and informal sensory results showed no significant differences between the antimicrobial treatments.
Significance: These results demonstrated that buffered dry vinegar ingredients were effective in inhibiting the growth of Lm; thus offering a promising solution for Listeria control in RTE meats.