Sustainable bioconversion of food waste into high-yield and low-RNA Fusarium venenatum mycoprotein

Conventional mycoprotein (MP) production necessitates resource-intensive glucose substrates and energy-intensive RNA removal process to mitigate health-risk-associated fungal RNA (5-6 %), resulting in substantial biomass loss and environmental burden. This study evaluated food waste (FW) as an alternative fermentation feedstock for Fusarium venenatum mycoprotein production, including cabbage, carrot, corn, and mixed food waste (MFW), with the aim of improving biomass productivity while reducing RNA content. The findings indicated that F. venenatum demonstrated substantial growth on FW, and the dry cell weight (DCW) was 32.68-74.16 % higher than that on the nutrient-rich glucose-based laboratory reference medium, while RNA content decreased by 35.16-54.91 %. Notably, MFW-MP reached 7.93 g/L DCW and 2.55 g/100 g RNA, approaching but remaining above the WHO-recommended 2 g/100 g level. Additionally, the protein content of FW-MP increased by 1.76-33.86 %, and the detected mycotoxins remained below selected international benchmark levels for relevant food commodities. Integrated transcriptomic and metabolomic analyses suggested that FW cultivation was associated with changes in translation-related pathways, RNA turnover, and central carbon/energy metabolism. Furthermore, life cycle assessment (LCA) showed that FW-MP reduced environmental impacts compared with the ISM-based glucose process. A prospective sensitivity scenario suggested that additional environmental benefits may be achieved if future strain or process optimization reduces RNA content below the recommended level. These findings provide guidance for future food waste valorization and sustainable mycoprotein development.