Abstract

• The extraction of pectinase enzyme from red dragon fruit peels was done by using ammonium sulphate precipitation (20 ̵ 80 %) method, and then the purification of the enzyme was done by using the gel filtration chromatographic method on Sephadex G-100. The enzyme activity was measured by utilizing DNS method to detect the release of the reducing sugar group. Specific activity, protein recovery, and degree of purification were measured in each purification step. The pectinase enzyme was purified 6.49-fold over crude extract, and protein recovery was found to be 8.43 %. The Km values of the crude and partially purified pectinase enzymes were found to be 0.1992 × 10-2 g mL-1 and 0.358 × 10-2 g mL-1, respectively. The reaction order (n) of the pectinase-catalyzed reactions was found to be first order. The activation energy (Ea) of the partially purified pectinase-catalyzed reaction was lower than that of the crude pectinase-catalyzed reaction. Both crude and partially purified pectinase enzymes were used in the clarification of apple juice, and good results were observed.