The effect of immobilization within alginate beads on the performance of araujiain in aqueous and nonaqueous media was studied. Optimum pH and temperature, thermal and pH-stability, kinetic parameters and operational stability were determined. Entrapped enzyme snowed an increase in thermal and pH-stability, a high activity over the studied pH range (5.0-9.5), ant a shift in optimum temperature from 37 degrees C to 70 degrees C. Immobilized araujiain retained 95% of their initial activity after 45 days of storage at 4 degrees 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. (C) 2011 Elsevier Ltd. All rights reserved.