Screening of bioactive components in grape and apple vinegars: Antioxidant and antimicrobial potential

Abstract

Vinegars contain several bioactive compounds that are characterized according to the type of the raw material, such as grape vinegars and apple vinegars. Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry was used for identification and quantification of phenolic compounds. Antioxidant properties of vinegars were determined by 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid assays. Antimicrobial activities of vinegarswere examined with an agar disc diffusion method with Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Gallic acid and chlorogenic acid were found to be the major phenolic acids accounting for the largest proportion of the total phenolic acid contents in grape vinegars and apple vinegars. Within the flavonols, quercetin-3-O-galactoside and quercetin were detected as the major compounds in grape vinegars. Apple vinegars were characterized by phloridzin, phloretin and high chlorogenic acid content. Antimicrobial activity results indicated that grape vinegars exhibited higher antimicrobial activity against tested bacterial strains correlated with their higher antioxidant capacity.