Abstract: | The purpose of this paper was to study the immobilization of two glycosidases, α-
-arabinofuranosidase (EC 3.2.1.55) and β-
-glucopyranosidase (EC 3.2.1.21), contained in a commercial preparation and purified as reported in Part I. The procedure which proved to be the best is simple and inexpensive to perform, employing the chitosan derivative, glyceryl-chitosan, especially synthesized and characterized, as a support. The glycosidases were adsorbed on this support and cross-linked with glutaraldehyde to prevent them from being released into the wine. Subsequent reduction of the biocatalyst with sodium borohydride allowed for improved stability. Finally, the immobilized glycosidases were compared with free ones in terms of optimum pH and temperature, stability over time, and kinetics parameters (Km and Vmax) after which they were employed for aromatizing a model wine solution containing aromatic precursors. |