Researchers at the University of Maine have developed a biodegradable food packaging material made from mushroom mycelium and wood-derived cellulose nanofibrils, offering a potential alternative to conventional plastic packaging while maintaining resistance to water and oil.
Concern about chemicals and plastic in food packaging has grown in recent years, particularly as studies show that more than a quarter of the approximately 16,000 chemicals used in plastics may pose risks to human health. Consumers and researchers alike are increasingly seeking sustainable materials that deliver the convenience and protective qualities of plastic without its environmental or health drawbacks.
The University of Maine research team turned to natural materials to address the challenge. Their solution combines cellulose nanofibrils, a plant-derived polymer sourced from wood, with a mycelial coating, the root-like structure of fungi. The resulting material forms a water- and oil-resistant barrier suitable for food packaging and can decompose naturally after use.
Mycelium forms dense networks beneath visible fungi such as mushrooms and is known for its water-resistant properties. The researchers leveraged this characteristic by pairing it with cellulose nanofibrils, which already possess grease resistance and biodegradability. Together, the materials create a layered barrier that protects food while avoiding synthetic plastics.
The coating process involves growing the fungus within a mixture that includes cellulose nanofibrils and nutrients such as malt extract broth, which fuels fungal growth. During the process, the microscopic branching filaments that make up fungal structures grow through the material, creating a uniform barrier layer. Once dried, the coating measures approximately 20 to 25 microns thick, about a quarter of the thickness of a human hair.
Researchers say the process can either coat existing materials, such as paper, or produce standalone films made entirely from cellulose nanofibrils and mycelium. The resulting material has a plastic-like feel on one side while retaining a slightly fuzzy texture on the other.
The team selected the fungus Trametes versicolor, commonly known as turkey tail mushroom, because it naturally grows on decaying wood and can use wood-derived cellulose nanofibrils as a nutrient source. Similar fungi have previously been used in applications such as binding particle boards.
One of the project’s key goals was to reduce production time. Traditional mycelium-based materials often require weeks to grow into usable forms. The researchers developed a method that shortens the process to about three days, a step that could significantly improve the feasibility of large-scale manufacturing.
To further scale production, the team is exploring methods that could adapt the coating process to existing industrial equipment. A roll-to-roll manufacturing approach could increase output from square centimeters per hour to square meters per hour, bringing the technology closer to commercial use.
The research comes as pressure grows to reduce plastic waste globally. According to the United Nations, an estimated 19 to 23 million tons of plastic enter rivers, lakes and oceans each year, while concerns about microplastics continue to mount.
Researchers involved in the project say the work demonstrates how natural systems can inspire new materials that integrate more harmoniously with ecosystems while maintaining practical performance.
KEY QUOTES:
“Plastics are very good at what they do, but then again so were forever chemicals and lead in paints and gasoline. It sometimes takes us a while to understand the long-term impacts of the things we invent, but the good thing is that when we do, we can change. The nice thing about fungi is that we already eat them, so we know that they’re going to be safe for us long-term. Nature has solutions, and as humans, we can look at and adapt to those solutions and better fit it in with our ecosystem, we don’t have to choose plastic.”
“Maybe we don’t need the fungus to grow through everything. Maybe we can just use it on the top as a layer. I think it opens a whole lot of new avenues for creating sustainable materials.”
Caitlin Howell, Associate Professor Of Bioengineering, University Of Maine
“Basically, we try to mimic what they need in nature. Everybody’s contributing here to make materials that are better nature-wise than it was previously. That’s a big motivation for me. If I go into the ocean, I see plastic. If I want my children to go into the ocean, they shouldn’t see it anymore.”
Sandro Zier, Chemical Engineering Ph.D. Candidate, University Of Maine
