A Very Efficient β-Glucosidase Catalyst for the Hydrolysis of Flavor Precursors of Wines and Fruit Juices

Abstract

Candida molischiana 35M5N β-glucosidase was immobilized to Duolite A-568 resin. Higher immobilization efficiency (86%) was achieved with citrate−phosphate buffer (0.1 M) at pH 4. The study of the immobilized β-glucosidase demonstrated that the physicochemical properties were similar to those of the free enzyme. Free and immobilized β-glucosidase were used to treat muscat wine and apricot fruit juice. GC−MS analysis indicated a significant increase in the flavor compounds nerol, geraniol, linalool, 2-phenylethanol, and benzyl alcohol in the muscat wine and linalool, α- and γ-terpinene, α-terpineol, 2-phenylethanol, and α-pinene in the apricot fruit juice. The immobilized β-glucosidase was found to be very stable under fruit juice or wine conditions and could be used repeatedly for several hydrolyses of bound aroma. The efficiency of this experimental catalyst was successfully tested with several fruit juices and wines containing various amounts of precursors. Keywords: Wines; fruit juices; aroma precursors; β-glucosidase; immobilization