Polyphenol oxidase in golden chanterelle (Cantharellus cibarius) mushroom

The golden chanterelle (Cantharellus cibarius) is an edible ectomycorrhizal mushroom much appreciated for its flavor and quite beneficial for the health through its antioxidant, immunomodulatory, anti-inflammatory and antimicrobial properties. Edible mushrooms are characterized by a short shelf life due to post-harvest changes resulting from the activity of enzymes such as polyphenol oxidase (PPO), responsible for browning reactions. Although the active site of PPO is conserved, its characteristics such as substrate specificity and sensitivity to inhibitors vary considerably among species. In this research, PPO activity was investigated and characterized in C. cibarius mushroom. Data showed that at least one soluble isoenzyme (similar to 90 kD) of PPO was detectable in C. cibarius extract. The enzyme oxidized monophenols and diphenols, with a maximum limiting reaction rate when p-cresol was used as substrate, and the highest catalytic efficiency when caffeic acid was the substrate. Activation by SDS and inhibition by kojic acid were observed, although to various extents, depending on the substrate used.