ABSTRACT
Nearly all food products contain macromolecules (or polymers). The most important ones are proteins (e.g., gelatin, milk proteins, and soy proteins) and polysaccharides [e.g., starch (amylose and amylopectin), pectin, and xanthan gum]. Polysaccharides and-to a lesser extent-proteins are often used for increasing the viscosity of liquid or semiliquid food products whereby the choice depends also on factors other than their thickening efficiency, such as nutritional and price aspects. Their effect on the viscosity of a solution strongly depends on the concentration, size, and shape of the molecules. In its most simple form, a macromolecule is a linear chain of covalently bonded identical monomers (e.g., amylose). Much more frequent are chains of nonidentical monomers (e.g., proteins, alginate, and carrageenan). Others are heavily branched (e.g., xanthan and amylopectin).
