This enzyme catalyzes the hydroxylation of monophenols to o-diphenols and the oxidation of o-diphenols to o- quinones. Quinones are very reactive compounds which strongly interact with other molecules, leading to a large pigment of high molecular weight with very dark or black coloring (Fig. 2) (Goulart et al., 2003; Montero et al., 2001). Melanin pigments,