Oxidase that performs selective oxidation of the terminal primary hydroxyl group of several alditols, with a reduction of O2 to H2O2. Shows highest activity on xylitol and D-sorbitol, and to a lesser extent, can also use galactitol, D-mannitol, and D-arabitol as substrates in vitro. Is not active on D-glucose, D-xylose, D-galactose, D-mannose, D-fructose, L-sorbose, L-fucose, myoinositol, glycerol, ethyl alcohol, and meso-erythritol. an alditol + O2 = an aldose + H2O2 O2 + xylitol = D-xylose + H2O2 D-sorbitol + O2 = D-glucose + H2O2 Binds 1 FAD covalently per subunit. Optimum pH is 7.5. Is stable in the pH range from 5.5 to 10.5. Optimum temperature is 55 degrees Celsius. Is stable at temperatures up to 65 degrees Celsius. Monomer. Belongs to the oxygen-dependent FAD-linked oxidoreductase family.