Bioinspired laccase-like nanozyme with high-density histidine‑copper site for efficient juice clarification in...

Residual phenolic compounds in beverages cause turbidity and negatively affect sensory quality. Although natural laccase has been widely used for phenolic oxidation and juice clarification, its industrial application is limited by high cost and poor stability. Herein, a bioinspired nanozyme with histidine‑copper (His-Cu) catalytic centers was developed for efficient laccase-like degradation of phenolic compounds. By changing the acetic acid concentration during synthesis and introducing ligand vacancies into the metal-organic framework, a higher density of His-Cu catalytic centers can be anchored, mimicking the active sites of natural laccases. Remarkably, the catalytic performance strongly depended on the density of His-Cu sites. The optimized nanozyme achieved up to 80% phenolic removal in apple juice with a turbidity reduction of 36.33%, and exhibited broad applicability in orange and tangerine juices, consistently outperforming natural laccase. These results demonstrate that bioinspired nanozyme with a His-Cu site is a sustainable strategy for improving beverage quality and value.