Immobilization of pectinase on chitosan-magnetic particles: Influence of particle preparation protocol on enzyme properties for fruit juice clarification

Highlights

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  Magnetic-chitosan particles were prepared in nano, micro and macro sizes.

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  Particle size was important for biocatalyst properties.

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  Nano-CMag presented highest activity recovery for pectinase immobilization.

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  Pectinase immobilized on Macro-CMag showed highest thermal and operational stabilities.

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  Pectinase-Macro-CMag was able to clarify orange juice for at least 25 repeated batches.

Abstract

Magnetic-chitosan particles were prepared following three different protocols enabling the preparation of particles with different sizes – nano (Nano-CMag, Micro (Micro-CMag) and Macro (Macro-CMag) – and used for pectinase immobilization and clarification of grape, apple and orange juices. The particle size had a great effect in the kinetic parameters, Nano-CMag biocatalyst presented the highest V _max value (78.95 mg. min ⁻¹), followed by Micro-CMag and Macro-CMag, with V _max of 57.20 mg.min ⁻¹ and 46.03 mg.min ⁻¹, respectively. However, the highest thermal stability was achieved using Macro-CMag, that was 8 and 3-times more stable than Nano-CMag and Micro-CMag biocatalysts, respectively. Pectinase immobilized on Macro-CMag kept 85% of its initial activity after 25 batch cycles in orange juice clarification. These results suggested that the chitosan magnetic biocatalysts presented great potential application as clarifying catalysts for the fruit juice industry and the great importance of the chitosan particles preparation on the final biocatalyst properties.