ABSTRACT
Gums, hydrophilic colloids, hydrocolloids, mucilages, and water-soluble polymers are but a few designations for materials that have the ability to thicken or gel aqueous systems. A contemporary classification of edible gums or hydrocolloids based on origin and derivation is shown in a table. Gums are not true colloids, but are rather polymers of colloid size which exhibit the colloidal properties of remaining suspended under the influence of gravity, and of not being visible under microscopic examination. In fact, gums or hydrocolloids actually form molecular solutions in most instances. The utility and importance of hydrocolloids is based upon their functional properties. Hydrocolloids are long-chain polymers that dissolve or disperse in water to give a thickening or viscosity-producing effect. The useful properties of hydrocolloids are due largely to physical effects, primarily those dealing with their interaction with water. Since most hydrocolloids happen to be polysaccharides, a basic understanding of hydrocolloids requires an understanding of polysaccharide chemistry.
