ABSTRACT

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Most food polysaccharides are classified as water soluble polysaccharides as they readily dissolve or disperse in hot or cold aqueous solutions. Water soluble polysaccharides are either naturally present or purposely added to food systems to control functional properties and provide desired textures of food products. The most important functional properties of food polysaccharides are water binding capacity and enhancing viscosity. As polysaccharides can dramatically increase the solution viscosity at a relatively low concentration, they are often used as a viscofier in liquid and semi-solid foods. They are also used to stabilize food products such as emulsion, foam, and frozen dairy products. Some water soluble polysaccharides may form gels that have been used for controlling many textural properties of semisolid foods. Polysaccharide gels are three dimensional, liquid water containing networks showing solid-like behavior with characteristic properties such as strength, hardness, and brittleness. All these functional properties exhibited by food polysaccharides are dependent on the structure, molecular weight, and concentration of the polysaccharides present. This chapter will focus on the physical properties of food polysaccharides and associated characterization methods.