Abstract

Enzymatic galactosylation offers a sustainable approach to modulate the physicochemical properties of phenolic compounds, yet systematic comparisons between beta-galactosidases from different glycoside hydrolase (GH) families and biocatalyst formats remain scarce. In this study, the enzymatic galactosylation of phlorizin was comparatively evaluated using permeabilised cells of Pantoea anthophila (PCPA) expressing a GH42 beta-galactosidase and a commercial GH35 beta-galactosidase from Aspergillus oryzae (F-Amano). Lactose was employed as galactosyl donor at concentrations ranging from 100 to 500 g L-1. Reaction kinetics, phlorizin conversion, and galactoside formation were monitored by HPLC-UV, while product profiles were characterised by UPLC-ESI-MS. PCPA achieved significantly higher phlorizin conversion (14.8-65.9%) than F-Amano (3.4-8.3%), both enzymes produced different monogalactoside isomers. F-Amano hydrolysed the products, including phlorizin to phloretin, while the phlorizin galactosides synthesis remain stable with PCPA.