Emulsões de óleos essenciais no controle de Listeria monocytogenes em embutido cozido e curado de peixe ; Essential oil emulsions for the control of Listeria monocytogenes in cooked and cured fish sausage

Listeria monocytogenes is a bacterium that causes food poisoning that multiplies in different types of foods, especially animal products such as meat, poultry and fish. To ensure consumer safety, meat sausages areadded with nitrate/nitrite salts. However, these preservatives do not have a very effective action against L. monocytogenes. Thus, alternative preservatives that can be used synergistically with nitrate/nitrite salts are of interest. Essential oils are promising for applications in food, especially in meat products, including those made with fish meat. Given the above, this work aimed to evaluate the inhibitory action of essential oil emulsions on L. monocytogenes inoculated in cooked and cured fish sausages, on contaminating lactic acid bacteria, as well as on the physicochemical characteristics of the product. The cooked sausage was made with fillet and mechanically separated meat (CMS) of tilapia and added with curing salts. Minimum bactericidal concentrations (MBC) of essential oils of garlic, oregano, coriander and clove on L. monocytogenes ATCC 19177 were determined in vitro, being respectively: 2%; 1%; 1% and 0.5% (v/v). Based on the CMB obtained, 27 trials containing different mixtures of essential oils were generated using the Central Rotational Composite Design (DCCR). All mixtures showed bactericidal action on L. monocytogenes in vitro. Evaluating the possible sensorial impact of each test on the product, test 10 was chosen, containing the oils of oregano, coriander, garlic and cloves in the respective concentrations of: 0.16; 0.05; 0.14 and 0.03% (v/v). The cooked and cured fish sausages were prepared containing the emulsion of essential oils and 75 ppm of sodium nitrite. A control was developed without the addition of essential oils. After cooking, 25 g samples were inoculated with 10 6 CFU/g of L. monocytogenes, vacuum-packed and stored at 10°C for 12 days. Samples separated for physicochemical analysis were not inoculated. L. monocytogenes and total lactic acid bacteria were quantified ...