Innovative Use of Cereals and Starch-Rich By-Products in Single-Cell Protein Production: Opportunities and Challenges

The growing worldwide need for sustainable, high-quality protein sources has intensified interest in single-cell protein (SCP) production, particularly mycoproteins derived from filamentous fungi. Concurrently, the agricultural sector generates vast quantities of starch-rich by-products, such as broken rice, cassava peels, potato waste and cereal processing residues, that remain largely underutilized despite their high carbohydrate content. This literature review examines the potential of starch-based agricultural by-products as low-cost, renewable feedstocks for mycoprotein production. Key topics include the chemical characteristics of starch residues, pretreatment and enzymatic hydrolysis strategies for efficient saccharification and the metabolic suitability of fungal strains such as Neurospora and Fusarium spp. for biomass and protein synthesis. In addition, the review evaluates optimization of fermentation processes, including maximizing biomass yield and improving overall feedstock valorization to enhance process efficiency. Furthermore, considerations related to process design, environmental benefits and techno-economic feasibility are evaluated in the context of converting starch residues into fungal protein. In summary, the evidence suggests that valorizing starch by-products for mycoprotein fermentation, used as a protein alternative and as an ingredient, represents a promising strategy to reduce waste, lower production costs and support global food sustainability.