Sustainable Valorisation of Coffee Waste as a Protein Source, Mycelium-Based Packaging Material and Renewable Energy Pellet

What if your morning coffee could build a package, feed a product, and power a city? Spent coffee grounds are no longer just waste—they're a treasure trove of protein, packaging, and energy.

Every day, millions of coffee grounds end up in landfills. But a new study reveals they hold untapped potential. Researchers extracted protein from spent coffee grounds using three methods: mechanical stirring, ultrasound, and CO2-assisted extraction. The CO2 method won, delivering 34.24% protein—more than the other two. It also preserved polyphenols and antioxidants best, proving that not all extraction is created equal.

After extracting protein, the remaining grounds were turned into mycelium-based packaging. The material showed impressive strength: a density of 0.551 g/cm³ and compression resistance of 3.354 MPa. That's sturdy enough for structural use, turning waste into a viable alternative to plastic.

Even after all that, the grounds kept their energy punch. Their calorific value was 19,887 J/g DW, barely dropping post-extraction. That means they can still fuel renewable energy pellets. So, your coffee waste could soon be a multi-tasker: protein source, packaging material, and clean energy. Who knew yesterday's brew held tomorrow's solutions?

Key Points

• CO2 extraction yielded highest protein at 34.24%.
• Mycelium packaging showed strength: 3.354 MPa compression.
• Calorific value stayed high: 19,887 J/g DW.