Immobilization on biomimetic silica nanoparticles as a highly effective strategy for the stabilization of Issatchenkia orientalis β-glucosidase in wine conditions

Abstract

β-Glucosidases (BGLs) are key enzymes for the hydrolysis of glycosidic aroma precursors of wines. However, BGLs produced by oenological yeasts are often inactive or unstable at typical wine pH values. In this work, different immobilization strategies on biomimetic NPs were tested to enhance the stability of Issatchenkia orientalis BGL and compared with traditional methods on agarose and Eupergit. Immobilization to biomimetic silica NPs by ionic interactions proved to be the most efficient method to achieve enzyme stabilization in model wine at pH 4.0. In particular, the subsequent glutaraldehyde crosslinking, achieved a high immobilization efficiency (71%) with an outstanding stabilization factor of 240-fold with respect to the soluble enzyme. This enzyme derivative preserved practically all the activity (98%) after15 days in model wine supplemented with Muscat glycosides, making possible its application for the release of aroma compounds relevant to the typicity of wine.