Effects of thyme and rosemary essential oils on the microbiology and shelf life of Italian Mortadella

Essential oils and different types of dietary fibres, are commonly used during food manufacturing for their nutritional and functional properties. The aim of the present study was to evaluate the effect of the combined addition of high concentrations of rosemary and thyme essential oils (0.025% and 0.05%) on microbiological properties of Italian Mortadella stored with different type of packaging conditions (air, vacuum and modified atmosphere packaged). Aerobic mesophlic bacteria (AMB), Enterobacteriaceae, lactic acid bacteria and Pseudomonas spp. were determined. The use of thyme and rosemary essential oil seems not to influence AMB, Enterobacteriaceae, Pseudomonas spp. and lactic acid bacteria growth. The addition of thyme and rosemary essential oils in Italian mortadella could not be considered as a technological alternative to reduce microbial growth and a good method to improve shelf-life of mortadellas.