CHAPTER 8 – Classifications

This chapter focuses on the classifications of polysaccharides that are broadly divided into two main groups: ionic and nonionic. Polysaccharides are systematically classified according to origin, isolation method, function, texture, thermoreversibility, and gelling time. The chemical classification of polysaccharides is the least ambiguous system of grouping these macromolecules. Polysaccharides of different origins can have similar structures as discovered in lemon and apple pectin or polysaccharides of the same origin can have different structures, for example, the concentration of pyruvate and acetyl substituents in xanthan, depending on incubation conditions. A table is presented that illustrates the properties and uses of polysaccharides in food. Starch belongs to a group of nonreducing glucose polysaccharides. and native starch is deposited in granules in plant tissues and is constructed of amylase and amylopectin bonding in the primary structure. Starch is considered to be a neutral molecule, but potato starch has a low degree of phosphation and is thereby endowed with weak polyelectrolytic character.