1. Introduction 2. Structural aspects and physicochemical properties of PPO and laccase Section A: Polyphenol oxidases 3. Substrate specificity and reaction mechanism of PPO 4. Functional roles of PPO 5. Recombinant PPO: production, purification, and activity assays 6. Application of PPO in the food industry 7. Emerging industrial applications of PPO 8. Recent advances in the design of PPO inhibitors Section B: Laccases 9. Reaction mechanism and redox potential of laccase 10. Biological functions of laccases 11. Challenges in the production of laccases 12. Challenges and applications of laccase in bioremediation 13. Redox mediators of laccase 14. Application of laccase in green chemistry 15. Immobilisation of laccase 16. Engineering of laccase through directed evolution and computational chemistry