Mycoprotein production from pectin side streams using enzyme-assisted fermentation

Overview

This consolidated bioprocess transforms pectin side streams — commonly citrus peel and apple pomace — into protein-rich mycoprotein through controlled enzymatic hydrolysis and fungal fermentation. Global protein consumption is still heavily dependent on animal-derived sources, creating ecological pressure; alternative protein platforms based on sustainable feedstocks are therefore important. The process uses food-grade cellulase and pectinase to release fermentable sugars from the cellulose, hemicellulose, and residual pectin in these processing residues. The resulting hydrolysate serves as a carbon source for the edible fungus P. ostreatus (oyster mushroom), which produces biomass that can be separated, washed, and processed into edible mycoprotein. This valorizes waste streams and supports sustainable protein diversification.

Technical specifications

Core features:

• Feedstock: pectin-rich residues such as citrus peel and apple pomace containing cellulose, hemicellulose, and residual pectin
• Enzymatic hydrolysis: pH-adjusted, food-grade cellulase and pectinase treatment releases fermentable sugars
• Fermentation: P. ostreatus cultured on the enzyme hydrolysate to produce protein-rich biomass
• Nitrogen strategy: residual nitrate in the side stream can partially replace the nitrogen source in the media, lowering cost
• Downstream processing: Biomass separation, washing, and processing into an edible mycoprotein product

Process optimization targets:

• Proximate and composition analysis of feedstocks (fiber, cellulose, hemicellulose, pectin)
• Hydrolysis optimization: solids loading, enzyme dosage, and time to maximize reducing sugar release
• Culture development: spore germination, inoculum preparation, and shake-flask studies of sugar concentration and nitrogen supplementation to maximize biomass yield and protein content
• Fermenter scale-up: 5 L fermenter with controlled aeration, agitation, oxygen transfer, pH and temperature, contamination control, and reproducibility

Technology readiness level

This technology is at an early development stage, approximately TRL 3–4. The planned validation proceeds in four phases: feedstock composition and enzymatic hydrolysis optimization; fungal culture development and shake-flask studies; 5 L fermentation scale-up; and pilot trials in collaboration with a fermentation partner to assess process integration, product recovery, and scale-up feasibility.