Yeast-based valorization of challenging side streams for food applications: precision vs. biomass fermentation

The growing demand for sustainable proteins and lipids, together with the environmental limitations of conventional food systems, is accelerating the search for alternative production routes. Yeast-based fermentation technologies provide a versatile platform for converting challenging side streams including agricultural or food residues and industrial by-products, into high-value food ingredients. This insights article examines both biomass fermentation and precision fermentation using conventional and non-conventional yeasts, highlighting their respective roles in protein and oil production from challenging substrates. Key yeast cell factories are compared in terms of robustness, metabolic flexibility, and suitability for circular bioeconomy applications. Advances in synthetic biology and strain engineering that underpin precision fermentation are highlighted, alongside the importance of downstream processing and regulatory considerations relevant to food applications. Major challenges remain in scale-up, infrastructure availability, regulatory harmonization, and consumer acceptance, which will ultimately determine industrial deployment. Overall, yeast-based fermentation from residues is positioned as a transformative technology capable of decoupling food production from agricultural land use.