A Rutgers scientist has developed a biodegradable, plant-based coating that can be sprayed on foods, guarding against pathogenic and spoilage microorganisms and transportation damage.
“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 Philip Demokritou, director of the Nanoscience and Advanced Materials Research Center, and the Henry Rutgers Chair in Nanoscience and Environmental Bioengineering at the Rutgers School of Public Health and Environmental and Occupational Health Sciences Institute. “And 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?”’
Demokritou added, “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 fibers that can wrap food directly. This is part of new generation, ‘smart’ and ‘green’ food packaging.”
The fibers encapsulating the food are laced with naturally occurring antimicrobial ingredients—thyme oil, citric acid and nisin. Researchers in the Demokritou research team can program such smart materials to act as sensors, activating and destroying bacterial strains to ensure food will arrive untainted.
The research was conducted in concert with scientists at Harvard University and funded by the Harvard-Nanyang Technological University/Singapore Sustainable Nanotechnology Initiative.
Their article, published in the science journal Nature Food, describes the new kind of packaging technology using the polysaccharide/biopolymer-based fibers. Like the webs cast by the Marvel comic book character Spider-Man, 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 material that encases food products is sturdy enough to protect bruising and contains antimicrobial agents to fight spoilage and pathogenic microorganisms such as E. coli and listeria.
The research paper includes a description of the technology called focused rotary jet spinning, a process by which the biopolymer is produced, and quantitative assessments showing the coating extended the shelf life of avocados by 50 percent. The coating can be rinsed off with water and degrades in soil within three days, according to the study.
The new packaging is targeted at addressing a serious environmental issue: the proliferation of petroleum-based plastic products in the waste stream.
“I’m not against plastics,” Demokritou said. “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 6 billion 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.”