Herbal and plant extracts are being applied for a wide range of foods against different types of food-borne pathogens. In the present study, ethanolic and aqueous extracts (2% w/v) from cranberry (Vaccinium macrocarpon) and pomegranate (Punica granatum L.) plants were applied alone or in combination with two essential oils (thyme and oregano in a concentration of 0.150 μg/g) in pork meatballs and their antimicrobial activity was estimated. The extracts exhibited promising results (aqueous and ethanolic extracts of pomegranate and cranberry in a food-compatible concentration of 2% w/v) were applied to raw pork meatball production and their antimicrobial activity was recorded versus Enterobacteriaceae, total mesophilic bacteria, yeasts/molds, Staphylococcus spp., Pseudomonas spp. and lactic acid bacteria (LAB). The outcome demonstrated that meatballs containing aqueous extracts of pomegranate were more resistant to spoilage compared to all the other samples since they were preserved for more days. The chemical profiles of plant extracts were determined through LC-QTOF/MS and the chemical composition of the essential oils applied was determined with the use of GC/MS in order to identify the substances involved in the observed antimicrobial activity. Phenolic acids (quinic acid, chlorogenic acid), monoterpenes (p-cymene, carvacrol, thymol, limonene), organic acids (citric acid) and phenols were the main constituents found in the plant extracts and essential oils applied. These extracts of plant origin could be used as natural preservatives in meat products, even in low concentrations.
Keywords: antimicrobial activity; antioxidant activity; essential oils; food-borne pathogens; plant extracts; pork meat.