The main function of hydrocolloids in food systems is to control and modify texture via changes in physical and geometrical properties. Texture is important in terms of both food palatability and eating safety, and hydrocolloids play a dominant role in controlling food texture. Hydrocolloids are thus the base ingredients for the development of food products. Research activities on food hydrocolloids have increased recently in terms of texture modifiers for nursing-care foods and also dietary fiber with physiological effects for an aged society, where the number of people with mastication and swallowing difficulties as well as patients with lifestyle-related disease are increasing. The author has aimed to analyze the fundamental properties of various food polysaccharides in terms of colloidal science and to obtain practical knowledge regarding food applications. Target materials for studies on gelling polysaccharides include gellan gum, carrageenan, curdlan, and methylcellulose, while pectin from sugar beet, gum arabic, and soybean soluble polysaccharide are targeted for those on emulsifying polysaccharides. Polysaccharides that control the gelatinization and retrogradation behaviors of starch have also been investigated, including galactomannan, soybean soluble polysaccharide, and gum arabic. This article reviews a part of these studies.
