The next time you sit down to a lobster dinner, think about how the animal's shell would look ground up and coextruded into a protective film to guard against food spoilage.
It's nearly impossible to do, because that film would be thousands of times thinner than a human hair.
The use of chitosan, an antibacterial polysaccharide derived from the shells of crustaceans, in new active nano- materials packaging is an example of the work being done in European laboratories to prolong product shelf life, said Jose María LagarÃ³n, senior research scientist at the Consejo Superior de Investigaciones Científicas-Instituto de Agroquímica y Tecnología de Alimentos (IATA) in Valencia, Spain.
Speaking at the Society of Plastics Engineers' Antec conference May 7 in Milwaukee, LagarÃ³n said his novel materials and nanotechnology group is working on several projects involving nanoclay films and nanofibers that can be combined with bioplastics to improve food safety and appearance by causing products, packaging and the environment to interact in a positive way.
``These are natural systems that are extracted from plants or even fruits, and we're trying to implement them into packaging systems. They can act as barriers to delay [bacteria] migration,'' he said.
IATA's latest project combines biodegradable polyester with a nanoclay containing thymol, a plant-based ingredient of many commercial mouthwashes.
The institute's research, LagarÃ³n said, is geared toward producing nanobiocomposites that processors can tailor to a packaging customer's specific food-storage needs. The trick is getting the nanoadditives to enhance the barrier properties of biofilms and also to control the release of germ-killing agents, LagarÃ³n said.
``If you're looking for ... packaging in a supermarket shelf, you want to have a standard [antibacterial] release; we need to have it for a long time. If you want a packaging system that is for fresh meat ... we need to have an immediate release, so the food pathogens will not grow there. It's all about controlling that,'' he said.
He said IATA's ultimate goal is to create natural solutions to food-packaging problems encountered with bioplastics, while keeping the plastics biodegradable.