Plants

[Abstract] Polyphenol oxidase (PPO) is an enzyme that catalyzes the hydroxylation of monophenols into ortho-diphenols (cresolase activity) and the oxidation of o-diphenols into quinones (catecholase activity) (Figure 1). These quinones spontaneously polymerize to form dark-colored phytomelanins, most often seen in the browning of damaged plant ...