Degrees of substitution (DS) is a term used in the field of chemistry, specifically in the area of polymer chemistry. It refers to the average number of reactive sites per monomer unit that have reacted with another species. In the context of modified starches, DS refers to the average number of substitution groups attached to the starch molecule per anhydroglucose unit, as a result of chemical modification. The DS of a modified starch determines its properties and functionalities.
The degree of substitution (DS) of a modified starch refers to the number of chemical groups that have been added to or replaced on the original starch molecule. It is expressed as the number of substituent groups per anhydroglucose unit. The DS affects the properties and functionalities of modified starches, such as solubility, viscosity, gelling and swelling power, stability to acid, heat and shear, as well as compatibility with other ingredients. For example, a high DS may result in increased solubility, while a low DS may result in improved gel stability. The properties of a modified starch can be tailored by adjusting its DS to match the requirements of a specific application.