Immobilization of pectinase onto chitosan magnetic nanoparticles by macromolecular cross-linker

• Published in: Carbohydrate polymers 2017-02, Vol.157, p.677-685
• Main Authors: Sojitra, Uttam V., Nadar, Shamraja S., Rathod, Virendra K.
• Format: Article
• Language: English
• Subjects: Chitosan magnetic nanoparticles; Dextran cross-linker; Immobilization; Juice clarification; Pectinase
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.10.018

•Pectinase immobilized onto chitosan MNPs by dextran polyaldehyde cross-linker.•Biocompatible, biodegradable functionalize and cross-linker used for immobilization.•Hydrolysis of pectin improve quality, stability and yield of fruit juice.•Thermal stability of immobilized pectinase was expressed as half-life.•Prepared magnetic pectinase nanobiocatalyst employed for apple juice clarification. Pectinase was immobilized onto chitosan magnetic nanoparticles (CMNPs) by dextran polyaldehyde as a macromolecular cross-linking agent. The parameters like cross-linking concentration, time and CMNPs to enzyme ratio were optimized. Further, prepared magnetic pectinase nanobiocatalyst was characterized by FT-IR and XRD. The thermal kinetic studies for immobilized pectinase showed two folds improved thermal stability in the range of 55–75°C as compared to free form. The Vmax and Km values of immobilized pectinase were found to be nearly equal to native form which indicated that conformational flexibility of pectinase was retained even after immobilization. The residual activity of immobilized pectinase was 85% after seven successive cycles of reuse, while it retained upto 89% residual activity on storage of fifteen days which exhibited excellent stability and durability. The conformational changes in pectinase after immobilization were evaluated by FT-IR spectroscopy data analysis tools. Finally, magnetic pectinase nanobiocatalyst was employed for apple juice clarification which showed turbidity reduction upto 74% after 150min treatment.