ABSTRACT
Hydrocolloids are commonly used by the food industry and are a widely encountered structural component present in many different food systems. They include a range of polysaccharides and proteins that are now also parts of the culinary cupboard. This chapter focuses on polysaccharides. The role of hydrocolloids as gelling agents and also as emulsifiers is detailed. The exact hydration and gelation temperatures are strongly dependent on the salts associated with the carrageenans. The chapter deals with the main polysaccharides that act as gelling agents, and focuses on their emulsifying usages as surface-active agents. Whether in industrial applications or for culinary purposes, the texture of an emulsion depends on the type of emulsifier used and depends even more on the concentration used. Hydrocolloids can act as emulsifiers due to their roles as viscosity modifiers, but some hydrocolloids in addition contain a surface-active component in their structure. These include exudate gums, starch, cellulose, pectin and proteins and are discussed in this chapter.
