Effect of wine-based marinades on the behavior of Salmonella Typhimurium and background flora in beef fillets

• Wine-based marinades exhibited significant antibacterial activity against S. Typhimurium.
• The addition of thyme essential oil remarkably increased the antimicrobial effect of marinades.
• Previous acid adaptation of S. Typhimurium did not enhance its survival in marinated fillets.
• All different strains of S. Typhimurium used to inoculate beef survived marination treatment.

The aim of this study was to evaluate the wine-based marinades to control the survival of acid-adapted and non-adapted Salmonella Typhimurium and background flora of fresh beef stored aerobically or under modified atmosphere. Beef slices were inoculated with a 3-strain cocktail of acid-adapted or non-adapted Salmonella Typhimurium strains DT 193, 4/74 and DSM 554 and marinated by immersion in wine (W) or wine supplemented with 0.3% thyme essential oil (WEO), for 12 h at 4 °C. Marinated slices were then stored under air or modified atmosphere conditions at 5 °C. S. Typhimurium and background flora were followed for a 19-day period of storage. S. Typhimurium individual strains were monitored by pulsed field gel electrophoresis. Marination with wine significantly (P < 0.05) reduced the background flora compared to the control (non-marinated). Furthermore, immersion of fillets in W or WEO marinades for 12 h significantly (P < 0.05) reduced the levels of S. Typhimurium compared to the non-marinated (control) samples by 1.1 and 1.4 log CFU/g or 2.0 and 1.9 log CFU/g for acid-adapted and non-adapted cells, respectively. Acid-adapted cells were more susceptible (P < 0.05) to the addition of thyme essential oil in the wine marinade. The epidemic multi-drug resistant DT 193, the 4/74 and DSM 554 strains survived marination (for both W and WEO) and were detected at about similar proportions as revealed by PFGE results. Present results indicate that wine-based marinades are efficient, from a safety and shelf life stand point, in reducing pathogen's levels as well as the background beef flora.