Water in Food: Composition and Functions

A solution is a mixture of a solvent and a solute where the solute particles are too large to dissolve completely.

A suspension is a type of colloidal dispersion where the solute particles are completely dissolved.

Water activity is a measure of the total amount of water present in foods.

Bacteria can survive in foods with a water activity of 0.85 and below.

Freezing is a method to increase the water activity of foods.

Drying is a method to reduce the water activity of foods by removing solutes.

The freezing point of water is the temperature at which a solid changes to a liquid state.

Water is a universal solvent in foods.

Bound water is easily separated from foods and functions as a solvent.

Moist heat transfer involves the use of air in the form of radiation.

Microwave cooking involves only radiation, without the use of water.

Water is present in most foods at a percentage of around 20-30%.