As food costs continue to rise and a global food crisis approaches the horizon, it’s amazing to think that about 30-40% of America’s food supply will end up in landfills, mostly because of spoilage. . At the same time, the World Health Organization estimates that foodborne diseases from microbial contamination cause about 420,000 deaths a year worldwide.
What if there was a way to pack fresh food that could extend its shelf life and eliminate microbial contamination?
Now, Harvard researchers John A. Paulson School of Engineering and Applied Sciences (SEAS) and Harvard T.H. Chan School of Public Health has developed a biodegradable and antimicrobial food packaging system that makes both.
“One of the biggest challenges in food supply is the distribution and viability of the food itself,” said Kit Parker, Tarr Family Professor of Bioengineering and Applied Physics at SEAS and senior author of in paper. “We are leveraging advances in materials science and materials processing to increase both the longevity and freshness of food items and doing so in a sustainable manner.”
The research was published in Nature Food.
From the battlefield to the farm
The new food packaging system has its roots in battlefield medicine. For more than a decade, Parker and his Disease Biophysics Group have been developing antimicrobial fibers for wound medications. To see also : Restaurant mix: New acai waves, food truck updates. Its fiber manufacturing platform, known as Rotary Jet-Spinning (RJS), has been specially designed for this purpose.
RJS works like a cotton candy machine – a liquid polymer solution is loaded into a reservoir and pushed out of a small opening by centrifugal force as the device rotates. When the solution leaves the reservoir, the solvent evaporates, and the polymers solidify to form fibers, with controlled diameters ranging from microscale to nanoscale.
The idea of translating research from wound clothing into food packaging was born out of a collaboration with Philip Demokritou, the former co-director of the Center for Nanotechnology and Nanotoxicology (NanoCenter) at the Chan School of Harvard. The NanoCenter is a joint initiative between Harvard and Nanyang University of Technology in Singapore.
“As it turns out, wound medications have the same purpose, in some ways, as food packaging – they support tissues, protect bacteria and fungi, and control moisture,” he said. Huibin Chang, a postdoctoral fellow in SEAS and lead author of the study. letter.
To make the fibers safe for food, the team turned to a polymer called pullulan. Pullulan is an edible, tasteless and natural polysaccharide that is commonly used in refreshing breath and mint.
The researchers dissolved the pollen polymer in water and mixed it with a variety of naturally derived antimicrobial agents such as thyme oil, nisin and citric acid. The solution is then spun into an RJS system and the fibers are deposited directly on a feeder. Researchers have demonstrated the technique of wrapping an avocado with pulling fibers. The result resembles a fruit wrapped in spiderweb.
The research team compared its RJS packaging to the standard aluminum foil and found a substantial reduction in contamination by microorganisms, including E.coli, L. innocua (which causes listeria) and A. fumigatus (which can cause disease in people who are immunocompromised).
“The high surface-to-surface ratio of the coating makes it much easier to kill dangerous bacteria because more bacteria come in contact with antimicrobial agents than in traditional packaging,” said John Zimmerman, a postdoctoral fellow in SEAS is co-author. of the card.
The team has also shown that its fiber packaging has increased the life of avocado, a notoriously finicky fruit that can turn from ripe to rot in a matter of hours. After 7 days on a laboratory bench, 90% of unwrapped avocados are rotten while only 50% of avocados wrapped in rotten antimicrobial fibers rot.
The packaging is also solely soluble in water and biodegradable, rinsed without any residue on the surface of the avocado.
Making food more sustainable
This antimicrobial and biodegradable food packaging system is not the first foray of the Disease Biophysics Group to make our food supply system more sustainable. To see also : Perry Food Pantry greets friends on Saturday in an open house.
Parker’s group used their RJS system to grow animal cells on edible gelatin scaffolds that mimicked the structure and consistency of meat. This technology has been licensed by Tender Food, a Boston startup that aims to combat the huge environmental impact of the meat industry by developing a new generation of vegetable-based alternative meat products that have the same structure, taste and consistency like real meat. .
The latest laboratory innovations in food packaging may also soon enter commercial development. Harvard’s Office of Technological Development has protected intellectual property in relation to this project and is now exploring marketing opportunities with Parker’s lab.
“One of the long-term goals of my research group is to reduce the environmental footprint of food,” Parker said. “We’ve done this by building more sustainable food so we can pack food in a sustainable way that can reduce food waste.”
This research was co-authored by Jie Xu, Luke A. Macqueen, Zeynep Aytac, Michael M. Peters, Tao Xu and Philip Demokritou.
It is supported by Nanyang-Harvard University of Technology T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology, under project number NTUHSPH 18003; the Harvard Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under award number NSF 1541959; and Harvard Materials Research Science and Engineering Center, under grant numbers DMR-1420570 and DMR-2011754.
Is there really biodegradable plastic?
(Not so) biodegradable – there is no such thing as eco-friendly plastic. Read also : Global food kilometers account for almost 20% of total food system emissions. Biodegradable plastics are always plastics – they are intended for short-term use and often stay in the environment for a very long time before being degraded.
Is biodegradable plastic still plastic? Face the confusion. There is no doubt, bioplastics are always plastics. Just because some are made from plants or have the potential to biodegrade under limited conditions, they cannot be declared as “safe from the planet”. For those claiming to biodegrade or compost, fine print is crucial.
Does polypropylene biodegrade?
However, most conventional plastics such as polyethylene, polypropylene, polystyrene, poly (vinyl chloride) and poly (ethylene terephthalate), are not biodegradable, and their accumulation increases in the environment has been a threat to the planet.
Is polypropylene plastic good for the environment? The manufacture of PP fiber from polypropylene is a process with little impact on the environment – no toxic waste, no toxic emissions, no fluorocarbons and no halogens.
Does polypropylene degrade in soil?
Abstract. Polypropylene (PP) has been widely used industrially in many sectors, especially in the packaging use of various products. Thus, this has accumulated in our environment due to incorrect disposal and its high resistance to degradation, causing a number of environmental impacts.
Why is polypropylene not biodegradable?
According to Peters, this is because the carbon-carbon bonds in polypropylene require too much energy to do so, so nature chooses other alternatives to hold large molecules together.
How long does it take for polypropylene to decompose?
Once in landfills, polypropylene degrades slowly and can take 20 to 30 years to completely remove. This feature raises enormous environmental concerns because the additives used in manufacturing may include toxins such as cadmium and lead.
Is PHA fully biodegradable?
PHAs are a well-known family of bacterial-based biodegradable plastics and offer an approach to carbon neutrality and support a more sustainable industry.
Can it be composed of PHA? CJ Cheiljedang’s PHA has been certified biodegradable in industry use, domestic compost, soil and water by TUV Austria, an institution for biodegradability testing and certification.
What makes PHA biodegradable?
The biodegradable medical polymers of natural bacteria PHA are a class of biodegradable and biocompatible plastics composed of polyesters of R-hydroxyalkanoic acids. They accumulate intracellularly as polymeric granules after culturing many Gram-positive and Gram-negative bacteria under nutrient-limiting conditions.
How long does it take PHA to biodegrade?
Biodegradable PHA bottles disintegrate in the soil in 2 months (but remain intact until they are discarded).
Do biodegradable bags decompose in landfill?
1. Biodegradable plastics cannot biodegrade if they are buried in the landfill or left in the sea. In fact, the Environmental Protection Agency (EPA) requires landfills to block air, moisture, and sunlight that are crucial elements for proper biodegradation.
Do compostable bags break? Compostable bags are made from natural plant starch, and do not produce toxic materials. Compostable bags break easily into a compost system through microbial activity to form compost.
Do biodegradable bags decompose?
If they are placed in an environment rich in microbes to help decompose, biodegradable plastic bags can take anywhere from just a few months to a few years to break completely. By comparison, traditional plastic bags, on the other hand, take hundreds of years to completely decompose.
Will biodegradable bags break down in landfill?
Most landfills do not reach the temperatures needed for compostable bags to break down, meaning that they are essentially mummified with other waste in the landfill. This is true of “bioplastic” bags, cups, and utensils, too, by the way.