Food Science and Technology

Food Colloids and Polymers

Food colloids give many different food products structure, texture, and mouth-feel; for example, jam, ice cream, mayonnaise, etc. Food colloid contains hydrocolloid that provides food products with thickening, gelling, emulsification, and stabilizing properties. Food polymers are edible plant, animal and micro-organism polymers that can be used in food systems, including proteins, polysaccharides, etc. Oils and/or lipids from plants and animals, although their molecular weights are relatively small, could also be considered as food polymers. The stabilization of food colloids represents an important functional property of food polymers. Proteins and polysaccharides are the two main types of food polymers found in oil-in-water emulsions, and some food emulsion products contain both types of macromolecules.

Examples: 1) Food colloids are sols, gels, emulsion, and foam. For example, egg white foam is a simple colloid system. Air bubbles (disperse phase) are trapped in the egg white (continuous phase) resulting in a foam.

2) Food polymers can be classified into three groups based on their sources: (1) plant-based food polymers, such as starch, dietary fiber, and cereal protein; (2) animal-based food polymers, such as meal protein; (3) microorganism-based food polymers, such as fungus polysaccharides.