Hydrocolloids are a group of chemical compounds characterized by  a high molecular weight because they are made of groups of molecules that are repeated forming polymers. Their origin can be vegetal, animal, microbial and synthetic.

What defines hydrocolloids is that they  have an elevated number of hydroxyl groups, by means of them, they are hydrated and retain much water, forming hydrogen bridges.

This capacity of water retention gives what we know as functional properties, that are physical-chemical properties that contribute to the stability and improvement of  sensory characteristics of a product, either food, cosmetic, personal care product or a pharmaceutical application and that generally leads to the perception of a superior quality of the consumer.  Hydration, water retention, vicscosity development,  gel formation, foam and emulsion are examples of  functional properties.

Among the group of functional polysaccharides are found gums, microbial polymers and synthetic polymers.

The term gum specifically refers to those polysaccharides that are obtained as plant exuded as gum arabic.  As examples of polymers produced by microorganisms and synthetics, xanthan gum and  carboxymetyl-cellulose are found respectively.