Optimization\nof Biocatalytic Rhododendrol Production\nfrom Biogenic Rhododendrol Glycosides

An enzyme-catalyzed synthesis of rhododendrol, an intermediate\nin the production of raspberry ketone, was investigated. The approach\ninvolves the enzymatic hydrolysis of rhododendrol glycosides into\nrhododendrol and a glycosidic residue. Rhododendrol glycosides, which\nare naturally derived from the inner bark of birch treesa\nrenewable resourcevary considerably in composition depending\non the origin of the plants. In this study, mixtures of betuloside\nand apiosylrhododendrin from natural resources were used in different\nproportions. An in-depth study was conducted to assess the feasibility\nof the process. A mathematical model was developed based on studies\nof the kinetics and operational stability of the enzyme. The model\nfor betuloside hydrolysis catalyzed by β-glucosidase was validated\nin batch, repetitive batch, and ultrafiltration membrane reactors.\nThe highest productivity, ranging from 83.9 to 94.5 g L<sup>–1</sup> day<sup>–1</sup>, was achieved in the latter. After screening\nnearly 50 enzymes, RAPIDASE emerged as a solution for the hydrolysis\nof apiosylrhododendrin, and the model was validated in a batch reactor.\nModel-based optimization enabled the prediction of input parameters\nfor different compositions of biogenic rhododendrol glycosides to\nobtain consistent process output metrics.