Fermentation of Monascus purpureus biomass as a new protein-rich food ingredient

Monascus purpureus, a filamentous fungus known for producing crimson yeast rice, offers not only high protein content but also bioactive compounds, such as alkaloids, phenols, and flavonoids, which provide antioxidant, anti-inflammatory, and anticancer properties. Although traditionally used as a colorant or dietary supplement, it has not been exploited as food biomass. This study optimized growth conditions for M. purpureus using solid state (SSF) and submerged-state fermentation (SmF), achieving biomass yields (dry weight) of 6 g/L in SmF and 4 g/L in SSF, with protein contents of 35 % and 21 %, respectively. Amino acid profiling revealed six essential amino acids, with lysine as the most abundant. The obtained biomass was characterized by gas chromatography coupled to mass spectrometry (GC–MS), identifying 17 compounds in SSF compared to 15 in SmF, including furfural derivatives, and fatty acids. Solid-state and submerged-state fermentation produced biomass with antioxidant levels (3.65 ± 0.14 vs. 3.33 ± 0.10 mmol TE/100 g, respectively). This work highlights the potential of M. purpureus biomass in food formulations, providing emulsifying properties without external additives, although with limitations in gelling and foaming capacities. This research establishes M. purpureus as a viable alternative protein, contributing to a sustainable food system and advancing global food security.