Engineering news
Aiming to provide an environmentally friendly way to keep food fresh and prevent damage during transportation, Philip Demokritou from Rutgers University in New Jersey worked with colleagues at Harvard University in Massachusetts to create the new coating.
“We knew we needed to get rid of the petroleum-based food packaging that is out there and replace it with something more sustainable, biodegradable and nontoxic,” said Demokritou, director of the Nanoscience and Advanced Materials Research Centre.
“We asked ourselves at the same time, ‘Can we design food packaging with a functionality to extend shelf life and reduce food waste while enhancing food safety?’
“And what we have come up with is a scalable technology, which enables us to turn biopolymers, which can be derived as part of a circular economy from food waste, into smart fibres that can wrap food directly.”
An article on the material describes the packaging technology using the polysaccharide/ biopolymer-based fibres. A process called focused rotary jet spinning is used to produce the biopolymer, and the stringy material can be spun from a heating device that resembles a hair dryer and ‘shrink-wrapped’ over foods of various shapes and sizes, such as an avocado or a sirloin steak. The resulting wrap is reportedly sturdy enough to prevent bruising and contains antimicrobial agents to fight spoilage and pathogenic microorganisms such as E. coli and listeria.
Assessments showed the coating extended the shelf life of avocados by 50%, a research announcement said. The coating can be rinsed off with water and degrades in soil within three days, according to the study.
“I’m not against plastics,” said Demokritou. “I’m against petroleum-based plastics that we keep throwing out there, because only a tiny portion of them can be recycled. Over the past 50 to 60 years, during the Age of Plastic, we’ve placed 6bn metric tons of plastic waste into our environment. They are out there degrading slowly. And these tiny fragments are making it into the water we drink, the food we eat and the air we breathe.”
The fibres encapsulating the food are laced with naturally occurring antimicrobial ingredients – thyme oil, citric acid and nisin. Researchers said they can programme such smart materials to act as sensors, activating and destroying bacterial strains to ensure food remains unspoiled.
The research was published in Nature Food.
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