Abstract This study explored the use of polysaccharide-based aerogels as supports for pectinase immobilization and tested their performance in apple juice clarification. Chitosan, alginate, and chitosan/alginate hybrid aerogels were loaded with a commercial pectinase by adsorption. Compared with free enzyme, immobilized enzymes showed lower maximum activity (Vmax) but stronger substrate affinity (lower Km). The hybrid aerogel had the best kinetic values, with both higher activity and good affinity. The optimal pH was around 5, and the optimal temperature was 40-50 °C. Immobilization also made the enzymes more tolerant to changes in pH and temperature. Reusability tests showed that the hybrid aerogels kept 83% of its activity after the second use and 31% after the fifth, while chitosan and alginate aerogels lost activity faster. Time-domain NMR showed that the hybrid aerogel had a more balanced water environment, and FTIR confirmed successful enzyme–aerogel binding. In juice trials, chitosan aerogel gave the best turbidity reduction but caused high loss of phenolics and darker color. Alginate aerogel reduced soluble solids the most but left higher turbidity. The hybrid aerogel kept phenolics and color closer to the free enzyme while also clarifying the juice. Overall, the hybrid aerogel gave the best balance between enzyme activity, stability, reusability, and juice quality, showing good potential for use in food processing.
Namli et al. (Thu,) studied this question.