Thermal inactivation of Salmonella Typhimurium in chicken shawirma (gyro)

This study explored the thermal characteristics (D- and z-values) of Salmonella Typhimurium in raw chicken shawirma. Marinated and non-marinated chicken breasts with skin were inoculated with S. Typhimurium 112 or S. Typhimurium 144. Inoculated samples were ground, packed in sterile bags and submerged in a water bath at 54, 56, 58 and 60°C for 2.5 to 72min. The mean D-values of S. Typhimurium strains in inoculated, non-marinated, ground raw chicken breast, as well as those of S. Typhimurium 15h after exposure to the marinade (inoculated before marinating, IBM) or after brief exposure (30min) to the marinade (inoculated after marinating, IAM) ranged from 9.15 to 12.44, 2.89 to 3.92, 1.06 to 1.30 and 0.32 to 0.52min at 54, 56, 58 and 60°C, respectively. Generally, no significant differences (P>0.05) were found among the D-values of S. Typhimurium in all chicken samples. However, the D-values of S. Typhimurium in raw ground chicken shawirma IBM were the lowest. The z-values of S. Typhimurium in all products ranged from 3.78 to 4.58°C. It was concluded that thorough cooking of the outside of the shawirma meat cylinder or cone before removal of slices at foodservice counters can enhance the safety of the product.