Characterization of pectinase from Geotrichum candidum AA15 and its potential application in orange juice clarification

Purpose: Pectinase is used in fruit juice industry to increase the juice yield and to enhance clarification process by reducing turbidity and viscosity. The current study was focused on characterizing pectinase preparation from Geotrichum candidum AA15 and to evaluate its application in clarification of orange juice. Methods: The pectinase preparation from AA15 was characterized to determine optimum temperature and pH for its activity and thermal stability under acidic environment. Considering the desirable attributes exhibited by the enzyme, it was applied for orange juice clarification and factors affecting the clarification process were optimized using response surface methodology (RSM) approach. Results: This enzyme exhibited the highest activity when incubated at 35 degrees C for 25 min in a buffer of pH 5. The enzyme did not lose any activity for up to 1 h at 30 degrees C. Whereas, activity was declined to 82% and 67% when incubated for 1 h at 35 degrees C and 40 degrees C, respectively. Moreover, stability of the enzyme when placed in the buffer of pH 2-3 was remarkable. The characteristics of extracted pectinase to work at mesophilic temperature under acidic environment presented it as suitable to be applied in fruit juice processing industries. Consequently, the factors affecting orange juice clarification, including temperature, treatment duration and enzyme loadings were optimized using RSM approach and clarification yield of 61% was obtained under optimized conditions. Conclusion: The pectinase preparation was found suitable to clarify orange juice and the data depicted the possible candidature of the strain for future biotechnological applications. (C) 2019 The Authors. Production and hosting by Elsevier B.V.