Chitosan

What Is It?

Chitin (kai-tin), one of the three must abundant organic compounds in nature (along with cellulose and starch), is the structural material found in the shells of crustaceans such as shrimp and crabs, and also in insect shells and fungi cell walls. From chitin we derive chitosan (kai-toe-zan). Chitosan is a natural wonder. Non-toxic, non-allergenic, anti-microbial, and biodegradable, it has a vast potential across industrial, nutritional, medical, and environmental fields. To top it off, it is a renewable resource obtained from commercial supplies of shrimp and crab shells. To turn the chitin into chitosan, the shells are taken through a simple process that is both environmentally friendly and cost effective.

Environmental and Development applications

In my field of environment conservation and community development, chitosan has incredible potential for water treatment. Chitosan is a polysaccharide molecule with a strong positive electrostatic charge that will attract suspended sediment particles, heavy metals, bacteria and even viruses, causing them to clump together and settle to the bottom. 1 part per million, or 1 teaspoon in 1300 gallons of water will turn a muddy industrial treatment pond into the Caribbean or treat hazardous waste water removing harmful heavy metals and organic compounds such as PCB’s. Similarly, a little chitosan in parasite infested water which is then filtered using a simple 55 gallon drum sand filter, will purify water to 5 time the US drinking water standards.

The applications are obvious. In the third world, chitosan would easily replace chlorine or boiling water as methods of purification. Chlorine has negative long-term effects on both the environment and health and does not remove all pathogens, particularly in water with large percentages of sediments and organics. As the world’s forests rapidly disappear, fuel to boil water is exceeding scarce in many regions of the world. In addition, the logistics of boiling several gallons of water in the family’s one and only cooking pot deters most third world communities from dealing with the incovenience. As chitosan becomes more available in third world countries, it will provide a superior alternative in water purification. Coastal communities will even be able to create micro enterprise production of chitosan from local shrimp and crabbing industries (very applicable to Southeast Asia).

The difficult part is making humanitarian and development agencies aware of the technology as well as third world businesses that could take advantage of it’s industrial applications, thus bringing it to their country where it can become accessible to the local people.

Other Applications

Medical Application: Chitin had wound-healing properties. Spun chitin filaments were developed in the 1970’s for sutures. These sutures enhance healing time by 35% to 50% and are absorbed by the body, eliminating the need for surgical removal. Chitin is also used to make dressings for burns, surface wounds, and skin-graft donor sites, which dramatically accelerate healing and reduce pain compared to standard treatments where the dressings must be removed. Other medical uses for chitin include anti-bacterial sponges and hospital dressings, artificial blood vessels, contact lenses, tumor inhibitors, dental plaque inhibitors, and blood cholesterol control.

Household products: These include sponges, diapers, feminine napkins, and tampons.

Dietary Supplements: Chitosan has been a fad fat blocker for many years in the United States. It has properties similar to plant fiber and can significantly bind fat, acting like a sponge in the digestive tract. It is not digestible itself and the bound fat leaves via the body without ever entering the bloodstream.

Cosmetics: Make-up powder; nail polish; moisturizers; face, hand, and body creams; and toothpaste are just a few consumer products that often contain chitin.

Agriculture: Seeds treated with chitosan are larger and stronger and more resistant to fungal diseases. Treating seeds with chitin can increase crop yields by up to 50%. Chitin is also added to commercial feed mixtures containing whey, a by-product of the cheese industry. Many animals find it hard to digest the high-lactose whey. Chitin supports the growth of beneficial microorganisms in the animals’ digestive tract that produce enzymes that help the animals digest the whey.

All this from shrimp shells.