Isolation and characterization of naringinase enzyme and its application in debittering of Pomelo juice ( Citrus grandis ): A comparative study with macroporous resin

Abstract

The naringinase enzyme was isolated from Citrus macroptera peel and pomace using Aspergillus niger for immobilization and debittering of juice. A comparative study of the effect of debittering using immobilized enzyme and resin on the physicochemical and phytochemical properties of the juice were carried out. The optimum hydrolytic conditions and Michaelis constant for an immobilized enzyme were observed at pH 4, 70℃, and 16.75 μg/ml, respectively. Adsorption of naringin onto resin followed pseudo‐first‐order with a regression coefficient of 0.92. Naringin content was reduced up to 73.28% in 4 min by resin and 79.76% in 120 min by the enzyme. We reutilized resin and immobilized enzyme effectively to debitter the juice upto 7 cycles. Treatment for less than 2 min and 90‐120 min using resin and enzyme respectively could retain the sizable amount of bioactive components in juice and immobilization retained 62% enzymatic activity during two months of storage at 4°C.