The global mushroom industry is growing rapidly, with production projected to reach 24 million tonnes by 2028. But for every kilogram of mushrooms harvested, 3.5 to 5 kg of spent mushroom substrate (SMS) is discarded. This organic waste—composed of cellulose, hemicellulose, and lignin—typically ends up in landfills, where it contributes to methane emissions, or is incinerated, releasing air pollutants. With 104 million tonnes of mushroom waste expected by 2026, finding a way to repurpose SMS is critical.
Transforming Mushroom Waste into High-Performance Films
A study published in the Journal of Agriculture and Food Research proposes a novel use for SMS: converting it into reinforced biodegradable films for food packaging. Researchers from Chiang Mai University extracted high-crystallinity cellulose from SMS using an eco-friendly deep eutectic solvent (DES)-based microwave-assisted pretreatment. This cellulose was then incorporated into carboxymethyl cellulose (CMC) composite films, enhanced with zinc oxide nanoparticles (ZnONPs) and mushroom powder (MP) to create a multifunctional, sustainable packaging material.
Performance and Sustainability
The resulting SMS-derived CMC films outperformed conventional biodegradable films in multiple ways:
Superior Mechanical Strength: The addition of SMS-derived cellulose increased tensile strength to 17.18 MPa and toughness to 4.72 MJ/m³, making the films more durable than many plant-based alternatives.
Antimicrobial Properties: Films containing ZnONPs exhibited strong antibacterial effects, effectively inhibiting Staphylococcus aureus, Escherichia coli, and Bacillus subtilis—key foodborne pathogens.
Antioxidant Activity: The inclusion of MP significantly enhanced the films' antioxidant properties, reducing the degradation of packaged food.
Thermal Stability: The films exhibited melting temperatures ranging from 257.5°C to 281.83°C, depending on composition, indicating a relatively high heat tolerance for biodegradable materials.
UV Protection: Films with ZnONPs provided improved UV-blocking capabilities, preventing light-induced spoilage.
A Breakthrough in Biodegradable Packaging?
Traditional bioplastics like PLA and PHA often require industrial composting conditions to break down effectively. In contrast, SMS-derived CMC films are biodegradable under natural conditions, offering a more circular and scalable alternative.
Using mushroom waste as a feedstock aligns with zero-waste initiatives, repurposing agricultural by-products while reducing reliance on petroleum-based plastics. The deep eutectic solvent (DES) method also eliminates the need for harsh chemicals, making this an environmentally friendly cellulose extraction process.
Scaling Up and Industrial Applications
While promising, scaling this technology for commercial use will require further development. Like a number of pilot scale biotechnologies, key challenges remain.
Optimising production efficiency to ensure SMS-derived cellulose can be produced at scale without excessive cost.
Regulatory approval for food-contact applications.
Further testing in real-world packaging scenarios to confirm long-term durability and safety.
With rising demand for eco-friendly packaging and growing regulatory pressure to reduce plastic waste, SMS-derived films could become a key player in sustainable food packaging.
This study demonstrates that spent mushroom substrate is far more than agricultural waste—it is a valuable raw material for next-generation packaging. By leveraging SMS-derived cellulose, researchers have developed a durable, antimicrobial, and biodegradable alternative to conventional plastics.
Research citation: Wichaphian, A., Yasan, P., Pathom-aree, W., Lumyong, S., Suwannarach, N., Kumla, J., Chaipoot, S., Hoijang, S., Krasian, T., Worajittiphon, P., Punyodom, W., Cheirsilp, B., Wang, G., & Srinuanpan, S. (2025). From agricultural waste to active films: Enhanced crystallinity of spent mushroom substrate-derived cellulose via deep eutectic solvent-based microwave-assisted pretreatment and its application in reinforcing CMC-based composite films. Journal of Agriculture and Food Research, 20, 101759.