Performance improvement of araujiain, a cystein phytoprotease, by immobilization within calcium alginate beads

The effect of immobilization within alginate beads on the performance of araujiain in aqueous and non-aqueous media was studied. Optimum pH and temperature, thermal and pH-stability, kinetic parameters and operational stability were determined. Entrapped enzyme showed an increase in thermal and pH-stability, a high activity over the studied pH range (5.0–9.5), and a shift in optimum temperature from 37 °C to 70 °C. Immobilized araujiain retained 95% of their initial activity after 45 days of storage at 4 °C, and it maintained 78% of activity after 20 hydrolytic reaction cycles. Furthermore, it showed a good performance in non-aqueous medium, used for the peptide synthesis of interest for the food industry, with a yield 2.6-fold greater than using free enzyme. The entrapped enzyme was more stable over a wide range of temperatures, pH, and storage time as compared to free enzyme.