Other exudates: Tragancanth, karaya, mesquite gum and larchwood arabinogalactans

The collection, processing and trading of plant exudate gums, other than gum arabic, and the production of arabinogalactan from the heartwood of Western larch tree represent an important economic activity in many regions of the world. What this family of materials shares in common is that they are comprised of highly branched heteropolysaccharide structures. This chapter addresses the manufacture, chemical structure, functional properties, main applications and regulatory issues for three well- established hydrocolloids, namely gum tragacanth, gum karaya and larchwood arabinogalactan along with those of mesquite gum, whose full potential utilization is still to be exploited in several fields of application.