Résumé
Effectiveness of combined steam (10 and 60 s, 70 °C and 98 °C) and chemical treatments, using concentrated solutions of lactic acid (1 and 30 min, 5% and 10% lactic acid), on the inactivation of Listeria innocua inoculated on the surface of chicken skins have been studied. Surviving bacteria on the skin were enumerated immediately after treatment, and after 7 days of storage at 4 °C. The most effective treatment was the combination of steam of 98 °C and 10% lactic acid with its immediate efficacy being mainly attributed to the applied heat treatment. However, after 7-day storage, the treatment's effectiveness was mainly due to the applied acid treatment, which prevented growth of the bacteria that survived the heat treatment. Milder treatments (70 °C steam, 5% lactic acid) revealed a genuine synergy between the heat and acid treatments, paving the way for an effective means of reducing bacterial load on the surface of poultry without affecting the product's raw appearance. (Résumé d'auteur)