Sorbitol, xylitol, erythritol and lactitol were used as the acceptors of galactosyl radicals, in the process of transgalactosylation accompanying the hydrolysis of lactose, conducted with beta-galactosidase (4.0 ml Lactozym 3000 was added to 430 ml 1.45 M lactose with 0.95 M polyhydroxyalcohols). The following concentrations of galactosyl derivatives of polyols were obtained after hydrolysis for 4 h at 40 degrees C: 0.31 M Gal-erythritol, 0.22 M Gal-xylitol, 0.18 M Gal-sorbitol and 0.14 M Gal-lactitol. A quadruple increase of xylitol content in dry matter of a solution (from 11.5% (w/w) to 44.5% (w/w) brought about a 2.3-fold increase of the product content in the solution (15.2% (w/w) of dry matter).