Introduction to food hydrocolloids

Abstract: This introductory chapter provides an overview of the source, market, functional characteristics and regulatory aspects of hydrocolloids used in foods. Examples of a number of different food products are given and the role of the hydrocolloids in controlling their texture and properties is discussed. A brief introduction to the rheological properties of the various types of hydrocolloids is provided and comparisons of the viscosity and viscoelastic behaviour are given. Many hydrocolloids are able to form gels in response to changes in temperature and/or in the presence of ions. The various mechanisms by which gelation occurs are summarised. The interactions that occur in systems containing mixtures of hydrocolloids are considered and combinations demonstrating synergistic behaviour are highlighted. The role of hydrocolloids as dietary fibre is an area of increasing importance because of the associated benefits for health and this area is briefly reviewed.