Purification and characterisation of polyphenol oxidase (PPO) from eggplant (Solanum melongena)

► Eggplant was found to be a very rich source of polyphenol oxidase (PPO). ► Native PPO was 259-fold purified using standard chromatographic procedures. ► The PPO was found to be a 112 kDa homodimer. ► The enzyme showed very low Km and high catalytic efficiency with 4-methyl catechol. ► GRAS compound cysteine hydrochloride was found to be an excellent PPO inhibitor.