Valorizing plant biomass residues through edible mushroom mycelial fermentation: From bioconversion to bioactive recovery and direct mycelium utilization in novel foods

Background Plant biomass residues are abundant and represents an underused resource for food-oriented valorization. Conventional chemical extraction, enzymatic hydrolysis and microbial conversion can recover specific fractions or generate value-added products, but their application to food-grade ingredient development is often constrained by lignocellulosic recalcitrance, process severity and product compatibility. Edible mushroom mycelial fermentation offers a complementary route by biologically opening resistant plant matrices and converting released nutrients into fungal biomass and metabolites under mild conditions. Scope and approach This review is structured around a central question: how can plant biomass residues be converted into food-relevant mycelial products? To address this question, it first examines how lignocellulosic recalcitrance limits conventional valorization pathways. It then summarizes and analyzes the potential of edible mushroom fermentation, including its metabolic capabilities and strategies for improving conversion efficiency. Finally, it links upstream bioconversion with downstream value creation through bioactive recovery, direct food use of mycelium, safety considerations and regulatory readiness. Key findings and conclusions This review evaluates edible mushroom mycelial fermentation as an integrated food-oriented bioconversion platform rather than merely as a biological pretreatment. Substrate deconstruction, inhibitor tolerance, mixed-sugar utilization and metabolism of lignin-derived aromatics allow plant residues to enter fungal biomass production. Pretreatment and substrate–strain matching are the most practical routes for improving this process, whereas co-cultivation and genetic engineering still face substantial constraints. The converted mycelium can serve as a source of bioactive compounds and as an ingredient for improving texture, flavour, nutrition and food-material functionality. For bioactive recovery, extraction strategies should be guided by compound localization, cell-wall barriers and solvent compatibility rather than empirical screening alone. Future studies should focus on nucleic-acid control, safety assessment and the differing regulatory requirements across jurisdictions.