Disaccharide Formation in Thermal Degradation of Lactose

Formation of oligosaccharides, especially disaccharides, from heating lactose in solid state and in molten state was examined.In heated lactose in solid state, lactulose, 3-013-D-galactopyranosyl-Dglucose, and 6-0-/3-D-galactopyranosyl-D-glucose were detected.In the molten state, 6-0-fl-D-galactopyranosyl-D-galactose was detected in addition to the former three disaccharides.The identity of these compounds produced from lactose was established by methylation analysis and hydrolysis.Analyses of the relative amounts of these disaccharides during the pyrolytic process showed that pyrolysis of lactose proceeded simultaneously through aldoseketose isomerization, hydrolysis of lactose, and condensation of the resulting monosaccharides in the primary stage without cleavage of the carbohydrate carbon skeleton.