Laccase-Mediated Degradation of Food Toxic Substances: Mechanisms, Applications, and Regulation Strategies

As a copper-containing polyphenol oxidase, laccase (EC 1.10.3.2), first isolated from the Japanese lacquer tree (Rhus vernicifera), is widely present in fungi, plants, and bacteria. It has shown considerable potential in food detoxification owing to its mild reaction conditions, broad substrate range, and environmental compatibility. This allows laccase to oxidize structurally diverse substrates, although catalytic efficiency varies with substrate structure, redox potential, and accessibility to the active site. Laccase can promote the degradation, transformation, removal, or detoxification of food toxic substances, including biogenic amines, polycyclic aromatic hydrocarbons, phenolic compounds, mycotoxins, and pesticide residues, through substrate oxidation initiated by electron transfer at copper-containing active sites. This review summarizes the mechanisms underlying laccase-mediated degradation, transformation, removal, and detoxification of food toxicants, together with optimization strategies including protein engineering, mediator regulation, and immobilization, supporting its development as a versatile biocatalyst for food safety control.