Application of predictive models to assess the influence of thyme essential oil on Salmonella Enteritidis behaviour during shelf life of ready-to-eat turkey products

Abstract

Consumers' demand for ready-to-eat (RTE) turkey meat is attributed to its convenience and healthy properties. However, as cooked meat product it is subjected to post-process contamination, thus allowing presence and growth of microbial pathogens, such as Salmonella spp.. The aim of this study was to include a natural antimicrobial, thyme essential oil (TEO), on RTE turkey products in order to evaluate its effectiveness throughout the shelf life. To do so, the effect of four different formulations of cooked RTE turkey products on Salmonella Enteritidis behaviour was investigated. Products' slices were surface inoculated with S. Enteritidis (ca. 4 to 5logcfu/g), subsequently stored at 10 and 25°C and microbiologically analysed during 18 and 12days, respectively. Predictive microbiology models fitted to count data were used to evaluate microbial behaviour. Results showed that S. Enteritidis behaviour on RTE turkey products slices during storage was strongly dependent on temperature. The pathogen was able to grow on slices at all tested conditions during storage at 25°C and no statistical differences were detected (p>0.05) between growth parameters. At 10°C, different behaviour patterns were observed. The application of TEO led to higher Salmonella inactivation rates on a product exempt of chemical preservatives. The addition of this novel antimicrobial on meat products or its incorporation on meat active packaging systems as a part of hurdle technology could increase RTE turkey products safety while satisfying the demand of more natural foods.