Hydrocolloids can be obtained from a wide variety of sources. The two most abundant polysaccharides are cellulose and starch. Cellulose is the key structural component of trees and is used on a huge scale globally in the pulp and paper industry. Starch in one form or another is the key carbohydrate in most peoples diet, whether it is in the form wheat or potato in Europe and the USA, Rice in Asia or Cassava in Africa.
Other hydrocolloids can be categorised depending on their original source (Table 1). The major hydrocolloids extracted from the marine environment are all derived from seaweeds. A smaller volume of Chitosan is extracted from shellfish exoskeletons but the market for this product has never really developed to a significant size.
| Raw material | Key products |
|---|---|
| Tree exudates | Gum Arabic, Tragacanth, Karaya |
| Seed flours | Guar gum, Locust bean gum, Tara, Cassia Tora |
| Plant fragments | Pectin, Cellulose |
| Fermentation | Xanthan, Curdlan, Gellan |
| Seaweed extracts | Carrageenan, Agar, Alginate |
| Animal derived | Gelatin, Chitosan, Isinglass |
| Table 1. Types and sources of hydrocolloids |