The effect of thermal treatment by cooking and storage on viability of Listeria monocytogenes in frankfurters

Listeria monocytogenes differs in several aspects from other pathogens transmissible through food. Considering the fact that it is widespread and significantly resistant to different unfavorable conditions of growth and development, such as low pH values and high NaCl concentrations, its microaerophilic and psychrotrophic traits, contamination of food with this pathogen has become one of the leading problems of public health and food industry. Except for that, the danger of contamination of food production plants is also based on its ability to survive for a long period in an external environment, as at very low temperatures (from 0°C to 7°C), even at temperatures of deepfreezing (>-20°C), so at high temperatures (from 60°C to 90°C). Knowing the basic characteristics of L. monocytogenes and with the intent of contributing to the improvement of health safety of foodstuffs and protection of consumer health, the goals of research were testing the effect of different temperature regimes of thermal treatment of frankfurters on the viability of experimentally inoculated L. monocytogenes. There were also tested the effect of different initial number of experimentally inoculated L. monocytogenes and technological process of production and storage on dynamics of its viability and growth in the researched meat products. The obtained results of our research pointed to the possibility of viability of L. monocytogenes in frankfurters with the effect of different temperature regimes of thermal treatment and storage. Considering our results, we recommend an obligatory control of foodstuffs to the presence of L. monocytogenes, together with the necessary education of food producers, farmers and general public on basic measures of protection against the contamination of food by a pathogen, as well as measures of prevention of alimentary listeriosis.