4 kinds of thickeners

Agar agar is the "vegetarian gelatine". It is sometimes also referred to as "kanten" (the Japanese term). It is derived from a South East Asian seaweed. This article sets out how to use agar agar.Agar agar is used throughout the world to provide a solid surface containing medium for the growth of bacteria and fungi. Microbial growth does not destroy the gel structure because most microorganisms are unable to digest agar. Agar is typically sold commercially as a powder that can be mixed with water and prepared similarly to gelatin before use as a growth medium.
Guar gum is a polysaccharide, a long chain made of sugars galactose and mannose. Some other familiar polysacharides are starch and cellulose, which are made of long chains of the sugar glucose. Guar Gum is normally undertaken by using process of roasting, differential attrition, sieving & polishing in the commercial production. The main properties of Guar Gum are as follows. Due to its various properties day by day new industrial application of Guar gum increases for commercial uses.
Pectin is a natural part of human diet, but does not contribute significantly to nutrition. The daily intake of pectin from fruits and vegetables can be estimated to be around 5 g. Amidated pectin is a modified form of pectin. Here, some of the galacturonic acid is converted with ammonia to carboxylic acid amide. These pectins are more tolerant of varying calcium concentrations that occur in use.Pectin is a complex carbohydrate, which is found both in the cell walls of plants, and between the cell walls, helping to regulate the flow of water in between cells and keeping them rigid. You’ll note some plants begin to lose part of this complex carbohydrate as they age.
Alginates are extracted from brown seaweed and are available in sodium, ammonium and potassium derivatives. They are soluble in both hot and cold water, and can thicken and bind. Sodium Alginate works as a cold gelling agent that needs no heat to gel. It gels in the presence of calcium compounds. Most commonly used with calcium chloride to make caviar and spheres. It is also used in indigestion tablets. Sodium alginate has no discernable flavor.