The objective of this study was to here evaluate the efficacy of an ethanolic extract of propolis (EEP) in the control of Listeria innocua PHLS 2030c (as a surrogate for Listeria monocytogenes) during storage of Alheira at 4°C.Total phenolic content was evaluated to determine the minimal inhibitory concentration of EEP against the growth of L.innocua by the agar dilution method.Alheiras were manufactured by incorporating EEP (0.28 mg/mL) and pathogenic bacteria and storage during 62 days at 4°C.
Growth of L.innocua was determined during storage.The behaviour of L.innocua in the food matrix was swisse high strength magnesium powder berry significantly affected (p < 0.01) by the addition of EEP.
The ethanolic extract of propolis reduced the Listeria population to below the detection limit of the technique after 8 days of storage.These results suggest that incorporation of EEP in a food susceptible to Listeria contamination may be an interesting alternative to existing chemical preservatives and can extend the shelf life of these products.