A hydrocolloid is defined as a colloid system wherein the colloid particles are dispersed in water. A hydrocolloid has colloid particles spread throughout water and depending on the quantity of water available that can take place in different states, e.g., gel or sol (liquid). Hydrocolloids can be either irreversible (single-state) or reversible. For example, agar, a reversible hydrocolloid of seaweed extract, can exist in a gel and sol state, and alternate between states with the addition or elimination of heat. Many hydrocolloids are derived from natural sources. Agar-agar and carrageenan are extracted from seaweed; gelatine is produced by hydrolysis of proteins of bovine and fish origins, and pectin is extracted from citrus peel and apple pomace. Gelatine desserts like jelly or Jell-O are made from gelatine powder, another effective hydrocolloid. Hydrocolloids are employed in food mainly to influence texture or viscosity. This book gathers the latest research from around the globe in the study of food hydrocolloids and highlights such topics as: collagen and gelatine extracted from skate skin, sucrose pectin interaction, utilisation of glucomannans for health and others.