Water Adsorption Characteristics of Acyclic Oligosaccharides of α-Gluose Studied by Near Infrared Spectroscopy

The adsorption properties of water molecules on maltooligosaccharides are attributed to the OH groups of the glucose rings in maltooligosaccharides. The water molecules are adsorbed onto OH groups by hydrogen bond formation. Near infrared spectroscopic and gravimetric techniques were used in analysing the adsorption characteristics of maltooligosaccharides. Near infrared spectra of the dry maltooligosaccharides were acquired during the adsorption of water molecules at a relative humidity of 50%. The amounts of water adsorbed by the samples were also recorded by an analytical balance. Second derivative techniques were used in decomposing the OH combination frequency of the adsorbed water molecules in the region 5300-5000 cm -1 .