Magnetic Janus SiO2 nanoparticles immobilized protease mutant T70I as a novel clarification agent for juice processing.

The juice processing industry offers several benefits, including promoting health and wellness through the delivery of beverages rich in nutrients. Nonetheless, the industry encounters significant challenges regarding new technologies for processing and preservation given that they can be costly and labor-intensive. In this study, magnetic Janus silica (SiO₂) nanoparticle which offers multifunctionality and high stability was synthesized and subsequently immobilized with a protease mutant T70I (T70I@MSNs) to serve as a clarifying agent in juice. The optimal conditions for the protease immobilized with SiO₂ nanoparticles showed superior tolerance and stability at pH 5 and 65 °C. Box-Behnken Design revealed optimizing conditions of 60 min, 50 °C and 0.2 % enzyme concentration which significantly influenced the clarification of the juice samples. Immobilized T70I@MSNs decreased >70 % of juice turbidity while maintaining about 78 % of enzyme activity after 7 consecutive cycles of reuse. Notably, T70I@MSN treatment enhanced certain volatile components by increasing alcohol and ester production, while changes in surface microstructure and functional groups were observed. This study highlights the significant improvement of magnetic Janus SiO₂ nanoparticles immobilized proteases in the clarification of juice against haze and undesirable properties, thereby offering a notable contribution to the juice processing industry.