The Star, January 19, 2015
BY CHRIS ARSENAULT
Packaging made from recycled crustacean shells could reduce the need for plastic wrappings to preserve fresh vegetables, reduce oil consumption and give food a longer shelf-life.
Chitosan, a bio-plastic made by isolating organic matter from shrimp shells, was shown to help preserve the shelf-life of baby carrots, in a new study published in the journal Postharvest Biology and Technology. “You can almost double the shelf-life of carrots with chitosan,” says Koro de la Caba, a professor of Chemical Engineering at the University of the Basque Country, who wrote the study.
“It is edible and better for the environment than plastics,” and the coating can’t be tasted, she says. In the study, chitosan was applied to the baby carrots as a spray, forming a thin packaging that kept it fresh for longer.
The researchers say that consumers could buy vegetables from a farmers’ market and spray them with chitosan to make them last longer in the fridge. The study shows that food waste, as in the case of discarded shrimp shells, can be a value-added product.
At present, however, chitosan, remains more expensive than plastic wrappings. More research is needed to improve the refining process and reduce the amount of electricity used in manufacturing chitosan, says Caba, following a meeting with Spanish companies on Jan 13.
“The sustainability aspect is attracting interest from consumers and thus manufacturers,” adds Caba. “But the economic aspect is still considered most relevant by companies.”
The low cost of oil – the key ingredient of plastic – could slow development of chitosan products, as companies have less incentive to change their approach to packaging and preserving food. So far, there has not yet been large-scale investment in improving manufacturing of the crustacean-based product, she says.
Humans produce 300 million tonnes of plastic per year and recycle only about 3%, according to Harvard University’s Wyss Institute. The remaining 97% is dumped in landfills and left to rot in oceans, harming the food chain and the environment.
In 2012, the Americas alone generated almost 14 million tonnes of plastics as containers and packaging, according to the US government’s Environmental Protection Agency. Only 9% of the total plastic waste generated in 2012 was recovered for recycling. – Reuters