Chemical Properties and Antioxidant and Antimicrobial Activities of Slovenian Propolis

<jats:title>Abstract</jats:title><jats:p>The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts <jats:italic>PEE70</jats:italic> and <jats:italic>PEE96</jats:italic>, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the <jats:italic>PEE70</jats:italic> was richer in total phenolic compounds than the <jats:italic>PEE96.</jats:italic> The Slovenian propolis was characterized by different phenolic acids and flavonoids. The <jats:italic>PEE96</jats:italic> was slightly richer in three specific compounds, <jats:italic>i.e.</jats:italic>, caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the <jats:italic>PEE70.</jats:italic> The <jats:italic>PEE70</jats:italic> showed a stronger reducing power and ability to scavenge free radicals and metal ions than the <jats:italic>PEE96.</jats:italic> Both PEEs were in the main more effective against <jats:italic>Gram</jats:italic>‐positive bacteria than against fungi and <jats:italic>Gram</jats:italic>‐negative bacteria like <jats:italic>Salmonella</jats:italic> and <jats:italic>Escherichia coli</jats:italic>, with the exception of <jats:italic>Campylobacter.</jats:italic> The <jats:italic>PEE96</jats:italic> decreased the intracellular oxidation in <jats:italic>Saccharomyces cerevisiae</jats:italic> in a dose‐dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.</jats:p>