D-galactose is a monosaccharide and belongs to the group of hexoses with six carbon atoms. The sugar, also known as mucilage sugar, occurs naturally in most living organisms as a building block of oligo- and polycondensates of carbohydrates in mucous membranes. Compared to household sugar, D-galactose has a lower sweetening capability and a lower caloric value. The melting point of D-galactose is around 160°C, making it suitable for preparing hot meals or baking.
Some key bacterial strains can utilise D-tagatose as a food source.