Hydration of starch refers to the process of absorbing water by starch molecules, which increases their volume and weight. This can result in changes to the physical properties of starch, such as its viscosity, gelation ability, and stability against temperature and mechanical stress.
Hydrogen bonding refers to the interaction between hydrogen atoms that are covalently bonded to an electronegative element such as oxygen, nitrogen, or fluorine. In the case of starch, hydrogen bonding occurs between the hydroxyl groups (-OH) of starch molecules, forming a network of hydrogen bonds that contributes to the mechanical and physical properties of starch. The extent of hydrogen bonding in starch affects its properties such as gelation, viscosity, and stability against temperature and mechanical stress.