ABSTRACT
Most food systems consist of aqueous mixtures of biopolymers that interact in several ways to produce various attributes that impact on quality, texture, and stability. Polysaccharides constitute an important group of biopolymers that interact under specific conditions to form three-dimensional networks, or structures, that bind the aqueous phase. These structures play important roles in the texture, flavor release, and stability of a wide range of food products, including dressings, desserts, jellies, and soups. Polysaccharide polymers, including, starches, pectins, xanthan, alginates, carrageenan, and locust bean gum, are widely used as thickening, stabilizing, and gelling agents. They are able to accomplish this through their ability to swell and absorb water and to reorder their molecular configuration through inter-and intrapolymer interactions and entanglements. As structure inducing/altering agents, they may modify flow behavior and properties to increase viscosity and yield stress. As gelling agents, they transform the viscous behavior of food with high moisture content to solidlike elastic behavior. Thus with the use of these polysaccharides, individually or in combination with others, it
is possible to fabricate products with rheological properties ranging from viscous to elastic. Rheological properties involving the flow and deformation characteristics of materials under stress are important in understanding these structures and in the handling, processing, mastication, and utilization of foods.
