Hydration of protein

Hydration of protein
Proteins can form hydrates with water. This reaction is very important in food science.

The protein molecule contains a number of groups, which contain a pair of unshared electrons and are therefore capable of attracting and binding the hydrogen of a molecule of water.

The water molecule which has been bound, attracts another molecule of water, and thus aggregates of water can build up around each polar group on the protein molecule.

The extend of hydration of a protein dispersion depends on concentration of protein, the pH, the temperature and the presence of other substance which combine with water.

Gelatin when placed in cold water swells, due to hydration. If it is heated, it dissolves. When cooled it solidifies again.

Thus the water is held in the network of swollen gelatin particles. Gelatin is useful as a gelling agent, a whipping agent in foam and as clearing agent in fruit juices, due to this property.
Hydration of protein