Combined Effect of Organic Acids and Modified Atmosphere Packaging on Listeria monocytogenes in Chicken Legs

SIMPLE SUMMARY: Chicken can be contaminated with pathogens such as Listeria monocytogenes and cause illness in consumers. The illness caused is called listeriosis, and it is a severe illness with high levels of mortality, particularly in susceptible individuals (pregnant women, neonates, the elderly and immunocompromised individuals). Consequently, it is important to control this pathogen in chicken meat. We evaluated the effect of packaging and natural compounds (citric, propionic and acetic acids) on this pathogen. We found that treatment of chicken with 2% propionic acid or 2% acetic acid can decrease L. monocytogenes counts in packaged chicken. ABSTRACT: The combined effect of organic acid (citric, propionic or acetic acid) treatment and modified atmosphere packaging (MAP) on the growth of L. monocytogenes in chicken legs kept at 4 °C for 10 days was evaluated. Chicken legs were inoculated with L. monocytogenes and washed with either 2% citric, 2% propionic or 2% acetic acid solution or distilled water (control). Legs were packaged under the following conditions: air, vacuum, 80% N(2)/20% CO(2), 60% N(2)/40% CO(2) or 40% N(2)/60% CO(2). The greatest L. monocytogenes growth reductions after treatment were observed in chicken legs washed with propionic acid (2.14 log units lower compared to control legs). The lowest growth rates of L. monocytogenes were found in samples washed with acetic acid and packaged in atmospheres containing CO(2). An extended shelf life was observed in legs packaged in 40% N(2)/60% CO(2), but these packaging conditions did not reduce L. monocytogenes growth. Consequently, it is necessary to design measures in order to control this bacterial pathogen. Washing of chicken with 2% propionic acid or 2% acetic acid can decrease L. monocytogenes counts in chicken packaged in MAP.