German researchers develop mushroom and agro-waste composite materials for packaging 

16 Sep 2024 --- Researchers at the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam, Germany, are creating packaging materials by mixing mycelium with agricultural residues such as wood chips, hemp and reeds.

Experts at the institute are working with mycelium from edible mushrooms and bracket fungi, such as oyster mushrooms and tinder fungi. 

These natural materials, when combined with agricultural residues, results in a composite material that can be shaped and treated to suit many applications. 

“Faced with climate change and dwindling fossil raw materials, there is an urgent need for biodegradable materials that can be produced with lower energy consumption,” shares Dr. Hannes Hinneburg, a biotechnologist at Fraunhofer IAP. 

“The mycelium has properties that can be used to produce environmentally friendly, energy-efficient materials, since the growth of the fungi takes place under ambient conditions and CO2 remains stored in the residues. When cellulose and other organic residues decompose, a compact, three-dimensional network forms, enabling a self-sustaining structure to develop.”

Mycelium-based trays

In collaboration with the Institute for Food and Environmental Research and Agro Saarmund, the researchers are developing packaging trays made from composites. These trays offer an alternative to conventional fossil-based plastic packaging. 

The versatility of the fungal network also allows it to be manipulated into forms, including insulation products and animal-free alternatives to leather goods.

“The many positive properties of the material, heat-insulating, electrically insulating, moisture-regulating and fire-resistant, enable an important step toward circular and climate-positive construction.”

According to the scientists, the growth process is both energy-efficient and adaptable. Variables such as temperature, humidity and the type of fungus used can be adjusted to produce materials with tailored properties — whether hard-wearing, elastic or tear-resistant. 

“Once the levels of humidity and particle size have been determined, and the subsequent heat treatment to kill off competing germs has been completed, the substrate is ready. It provides food for the fungi and is mixed with the mycelium,” Hinneburg explains. 

The mycelium-based materials look similar to their leather counterparts (Image credit: Fraunhofer-Gesellschaft).“Following a growth phase of around two to three weeks in the incubator, the mixture will produce, depending on the formulation and process used, a substance similar to leather or a composite that can be processed further.”

Innovative production methods

However, according to the researchers, scaling these innovations for commercial use presents challenges. The availability of biogenic residues, maintaining consistent product quality and achieving efficient mass production are hurdles to bringing mycelium-based materials to market. 

To address these challenges, the researchers have developed a roll-to-roll method, for which they have already created a prototype. It enables continuous production under controlled conditions. This standardized process ensures consistent material properties and increases resource efficiency, allowing for the production of mycelium-based products on an industrial scale.

“This is crucial in order to meet the growing industry demand for sustainable materials and to become less dependent on petroleum in the long term. Production can also be improved further by using innovative technologies such as artificial intelligence to optimize the combination of residues and types of fungi,” says Hinneburg.

Last year, Finnish scientists developed durable, lightweight materials from the Fomes fomentarius mushroom, offering potential as a reusable, biodegradable plastic alternative. The mushroom’s unique structure features three distinct layers with different properties, inspiring the creation of high-performance, ultra-lightweight materials.

Halfway around the world, researchers from Shinshu University, Japan, this year developed a method to obtain mycelial fibers from mushroom cells by bleaching them under sunlight, preserving their structure. The “mycelial pulp” can be used in making packaging due to its formability.

Companies are also exploring the commercial potential of fungi right now. UK-based Magic Mushroom Company went into a large-scale production of its mushroom-derived home biodegradable packaging.

Regarding related safety concerns, the Food Standards Agency tells Packaging Insights about the caution when using products that combine plastic with plant-based materials. It also clarifies that products made entirely from plant-based materials are deemed safe for use.

By Sichong Wang