By Chris Arsenault
ROME (Thomson Reuters Foundation) - 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, a Spanish study said.
Chitosan, a bioplastic made by isolating organic matter from shrimp shells, helped preserve the shelf-life of baby carrots, said the study, published in the journal Postharvest Biology and Technology.
"You can almost double the shelf-life of carrots with chitosan," said 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 said. Consumers could buy vegetables from a farmers' market and spray them with chitosan to make them last longer in the fridge - if the product could be mass produced effectively.
The study "Quality attributes of map packaged ready-to-eat baby carrots by using chitosan-based coatings" showed that food waste can be a value-added product, once technologies for processing and refining it become economically viable on a large scale.
Chitosan, which can be applied as a spray or dip directly onto fresh vegetables, or as a form of thin packaging, 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, she said, following a meeting with Spanish companies on Tuesday.
"The sustainability aspect is attracting interest from consumers and thus manufacturers," Caba told the Thomson Reuters Foundation. "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.
There has not yet been large-scale investment in improving manufacturing of the crustacean-based product, she said.
Humans produce 300 million tonnes of plastic per year and recycle only about 3 percent, according to Harvard University's Wyss Institute. The remaining 97 percent 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 U.S. government's Environmental Protection Agency.
Only 9 percent of the total plastic waste generated in 2012 was recovered for recycling.