Reorganizing the data to directly compare these simple amines within specific conditions highlights their distinct reactivities with catechol (Fig. ). In unbuffered assays, Pro steadily enhanced browning in a linear manner, while Gly and Tris had modest effects, and Lys emerged as the most potent enhancer (Fig. ). At pH 7.4, the enhancement hierarchy shifted to Tris < Gly < Lys < Pro (Fig. ). At pH 7.8, Gly and Pro showed markedly amplified effects, though the enhancement hierarchy remained consistent (Fig. ). These observations suggest that simple amines play complex, dual roles based on their individual physicochemical characteristics. They act as bases to deprotonate catecholic compounds and facilitate oxidation -particularly in insufficiently alkaline environments -and as nucleophiles to attack oxidized o-quinone species. Notably, differences in enhanced browning rates -and presumably, nucleophilicity -persist even under buffer-controlled conditions at pH 7.4 and 7.8, where assay pH was stabilized within 0.11 units or less across all amine concentrations (Table ), underscoring the distinct contributions of each amine to the reaction dynamics.