Guar is a natural water soluble polymer principally grown in the Asian subcontinent, specifically India and Pakistan. Also, guar gum is a crop studied in agronomy programs in the United States and many other parts of the world.
The guar plant is a pod bearing and nitrogen-fixing legume. The seeds of the plant are composed of a hull, germ, and endosperm (gum containing portion) must be separated as cleanly as possible from the hull and germ. After the endosperm is separate from the hull and germ, it is ground into guar gum powder.
The guar gum is a galactomannan with a structure composed of a straight backbone chain of D Mannopyranose units with a side branching unit of D Galactopyranose on every other unit (see Figure 1). The average molecular weight is in the range of 200,000-300,000.