Emerging Natural Hydrocolloids

1 Introduction to Emerging Natural Hydrocolloids

Seyed M.A. Razavi

Food Hydrocolloids Research Center, Department of Food Science and Technology, Ferdowsi University of Mashhad, PO Box: 91775‐1163, Mashhad, Iran

1.1 Introduction

Hydrocolloids, also known as gums, are a diverse group of long‐chain and hydrophilic polymers with high molecular weight which are readily dispersive, fully or partially soluble, and prone to swell in water, thus producing colloidal systems of different structures. Therefore, a hydrocolloid is a highly water‐soluble (or water‐dispersible) material that readily dissolves (or disperses) to form highly hydrated entities of colloidal dimensions (1–1000 nm) [1,2]. Hydrocolloids generally produce a dispersion, which is intermediate between a true solution and a suspension, and exhibit the properties of a colloid [3]. Each dissolved polymer molecule of a hydrocolloid ingredient is deemed to interact strongly via hydrogen bonding with its surrounding water molecules as well as with any neighboring hydrocolloid molecules. Due to the tendency of these large hydrophilic macromolecules to overlap and join together into entangled networks and macroscopic gels, most hydrocolloids have the capability to function as viscosity modifiers and thickeners in aqueous media at relatively low concentrations [4]. The presence of many hydroxyl groups in their structures conspicuously increases the affinity for binding water, rendering them hydrophilic. At sufficiently ...