Phenolics and anthocyanins in berries of European cranberry and their antimicrobial activity

European cranberry is a berry plant rich in biologically active substances, making it valued by both the phyto-pharmaceutical and food industries. The aim of this study was to examine the accumulation of phenolic compounds and anthocyanins in berries of European cranberry and to assess their antibacterial activity.

Different wild clones of European cranberry were investigated according to berry weight and the amounts of total phenolics and anthocyanins. Anthocyanin profiles of extracts were evaluated by HPLC, whereas the antimicrobial properties were determined by the agar well diffusion method. A strong negative correlation between berry weight and the amount of anthocyanins was found. The amount of total phenolics among different cranberry clones in the field collection ranged from 224.0 mg/100 g to 498.0 mg/100 g, and the amount of total anthocyanins ranged from 40.7 mg/100 g to 207.3 mg/100 g. Quantitative HPLC-UV analysis revealed six anthocyanins in the berries of European cranberry, among which the anthocyanin peonidin-3-galactoside was most prevalent.

Investigation of the antimicrobial properties showed that European cranberry extracts inhibited the growth of wide range of human pathogenic bacteria, both gram-negative (Escherichia coli and Salmonella typhimurium) and gram-positive (Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, and Bacillus subtilis).