Use of essential oil treatments to control the Listeria monocytogenes growth in various food commodities

Essential oil obtained from Satureja thymbra [1] was used to monitor the growth/death of Listeria monocytogenes on various food commodities of Greek market, such as minced meat, salami, bologna sausage, ham, fish (Sparus aurata), lettuce, cheese-salad, gouda-cheese and soft cheeses (metzethra and anthotyros). For this purpose, a „smart“ packaging system was developed and used. Two levels of pathogen inoculation were studied, one high (10⁵ CFU/g) and a low level (10² CFU/g), at two distinct temperatures (ambient 20°C and refrigeration, 5°C).

Best results were obtained at higher temperatures and low inoculum levels. The effects of the essential oils were connected to the pH and fat content of the samples studied, indicating that the dairy products are more susceptible to the essential oil action. Therefore, the essential oil of Satureja thymbra represents an inexpensive natural mixture that possesses potentials for practical application in food systems to prevent the L. monocytogenes growth and extend the shelf life of the processed food.

References: 1. Chorianopoulos, N. et al. (2006)J. Agr. Food Chem. 3:139–3145.