A variety of hydrophilic substances act as thickening agents
to increase the viscosity of liquid mixtures and solutions,
and their emulsifying properties. Thus, these agents aid
in maintaining the stability of the mixtures or solutions.
Four types of thickening agents are known: (a)
starches, gums, casein, gelatin and phytocolloids, (b)
semi-synthetic cellulose derivatives like carbon methyl
cellulose, (c) polyvinyl alcohol and carboxy vinylates,
and (d) bentonite, silicates and colloidal silica. The first
group is widely used in the food industry especially in ice
creams, confectionaries, gravies, etc. The other major
consumers, are in the paper, adhesive, textile and
detergent industries.
