Genipin-activated chitosan particles as support of pectinase immobilization and their application as stable biocatalyst for fruit juice clarification

In this work, we assessed genipin activation of chitosan particles and pectinase immobilization parameters, and after applying these biocatalysts for fruit juice clarification. Support activation pH and enzyme load, along with immobilization pH, were evaluated. Pectinex Ultrapulp was used for enzyme immobilization. The immobilized enzyme maintained around 60% initial activity after 5 h at 60ºC, compared to free enzyme's rapid decline in <1 h. Orange juice clarification showed no statistical difference between free and immobilized enzyme, while grape juice clarification exhibited a significant increase with immobilized enzyme compared to free enzyme. In pectin (0.1%) hydrolysis batch test, the immobilized preparation retained 40% relative initial activity over 20 batches. For fruit juice clarification stability, an improved washing approach, to remove adsorbed juice particles in the biocatalysts, helped maintain 40% initial capabilities after 10 cycles. This study demonstrates the potential of genipin-activated chitosan particles for immobilizing pectinase and enhancing fruit juice clarification.