Antimicrobial activity of American cranberry extract in the antimicrobial protection of minced pork meat

Abstract

The aim of the study was to determine the content of bioactive ingredients in the American cranberry extracts (Vaccinium macrocarpon), the antimicrobial activity of these extracts and the efficiency of the selected extract in minced pork meat together with its sensory evaluation. Three extracts were made: aqueous (w-FACE), ethanol (e-FACE) and aqueous-ethanol (we-FACE). The content of bioactive components was tested by HPLC. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined against ten Gram-negative bacteria strains and six Gram-positive bacterial strains by serial macrodilution method. Minced pork meat with or without addition of 2.5% w-FACE was inoculated with four pathogenic strains (Escherichia coli, Salmonella Enteritidis, Listeria monocytogenes and Staphylococcus aureus) and stored at 4°C for 6 days. In 0, 2, 4 and 6 day, the number of bacteria was determined by plate method. Sensory evaluation of meat samples with and without in-FACE included general appearance and smell. All extracts contained organic acids (p-coumarin, benzoic, chlorogenic and coffee) and flavone (quercetin, miristin, epicatechin and isorhamnetin). E-FACE also contains ursolic acid. The MIC/MBC values of the extracts were in the range of 1.56-6.25 (3.13-25.0) mg/ml against Gram-positive bacteria and 6.25-12.5 (6.25-25.0) mg/ml against Gram-negative bacteria. Statistically significant (p ≤ 0.05) inhibition of growth of all pathogens in minced pork meat containing in-FACE was found. The 2.5% w-FACE had no significant effect (p ≤ 0.05) on the initial sensory characteristics of minced pork meat and after 4 and 6 days of storage was significantly higher than that of FACE-free meat. The results of the study suggest the possibility of using an aqueous extract of cranberry fruit as a natural preservative of minced pork meat..