Quick Dips

Waste Not,
Want Not

What do you do with the shell after you've eaten a crayfish? Throw it away of course. But now you could save it for use in a whole range of pharmaceutical and industrial applications.

The useful substance is the chitin in the shell. Industrial Research scientists are using lactic acid produced by fermenting dairy effluent to extract the chitin, in order to make chitosan, which has a range of applications in pharmaceuticals, cosmetics, biotechnology, and the clarification and purification of water and other beverages.

There is already a good market for chitin and chitosan, and other countries are also producing it from waste crustacean shells. Rod Shaw and Peter Bain of IRL Gracefield came up with an idea for a new extraction process, much gentler than the hydrochloric acid process widely used elsewhere. The product also benefits from the fact that New Zealand's very clean seawater makes for higher grade chitin in the shell.

"We think the quality of the chitin we've got is vastly superior to that which is commercially available," says Shaw.

Work on the fermentation has been done in conjunction with a biological process development team in Palmerston North. As well as producing high-quality chitin, the use of lactic acid avoids the use of more expensive and hazardous substances. Researchers are now looking for commercial developers to take the project out of the laboratory.