Immobilization and stabilization of pectinase on an activated montmorillonite support and its application in pineapple juice clarification

Abstract

One of the important commercial usages of pectinase is the depectinization and clarification of fruit juices. The application of native enzymes for industrial utilization has limitations such as high production cost, instability with operational conditions, difficulty in separation of products from reaction media, and lack of reusability. In this study, pectinase from Aspergillus aculeatus was immobilized on silylated-montmorillonite clay as available and an inexpensive carrier using glutaraldehyde as a cross-linker agent. The pectinase-loaded carriers were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The immobilization method did not affect the optimum temperature and the thermal stability of pectinase for achieving the maximum activity, but the immobilized enzyme was more active in acidic pH. Km and Vmax value after immobilization process was decreased. The immobilized pectinase was reused for up to 6 repetitive cycles, retaining 60% of its initial activity. The immobilized pectinase was used for pineapple juice clarification and the clarification rate of the immobilized pectinase was higher than that of the free pectinase throughout the experimental period. The proposed methodology may be a convenient alternative to obtain new biocatalysts the fruit juice industry.