Abstract: This study was designed to explore the inhibitory effect of polyphenols from Aronia melanocarpa berries on α-amylase activity and their antibacterial activity. The antimicrobial activity against Escherichia coli, Staphylococcus aureus, Aspergillus flavus, Aspergillus fumigatus, Rhizopus oryzae, Penicillium islandicum and Trichoderma koningii was investigated by the filter paper disc method, and the influence of temperature and pH on the inhibition of Staphylococcus aureus and Aspergillus fumigatus was examined. The inhibitory effect of Aronia melanocarpa polyphenols on α-amylase were studied by kinetic modelling. The results demonstrated that Aronia melanocarpa polyphenols inhibited all seven strains tested. Among them, the strongest inhibitory effect against Aspergillus fumigatus was observed with a minimal inhibition concentration (MIC) of 0.171 9 mg/mL. At pH 5.0, Aronia melanocarpa polyphenols had the strongest antibacterial activity against Staphylococcus aureus. But the antibacterial activity against Aspergillus fumigatus could be destroyed by changing the pH. Furthermore, Aronia melanocarpa polyphenols had an obvious inhibitory effect on α-amylase. Compared with the positive control of acarbose, Aronia melanocarpa polyphenols were more active against α-amylase within the concentration range of 0.10–0.70 mg/mL. The inhibition was non-competitive and reversible and the inhibition constant was 0.193 2 mg/mL. Aronia melanocarpa polyphenols enhanced the ultraviolet absorption intensity of α-amylase at 202 nm and led to a redshift in the absorption peak wavelength. Therefore, Aronia melanocarpa polyphenols can be used as a new α-amylase inhibitor and antimicrobial agent.

Key words: Aronia melanocarpa, polyphenol, antimicrobial activity, α-amylase inhibitor