Alterations of Fusarium venenatum mycelium upon sequential processing mediate the interfacial behavior and emulsion stability.

As a promising sustainable source of mycoprotein, Fusarium venenatum (F. venenatum) offers high protein content, and a well-balanced amino acid profile. Prior to food application, F. venenatum mycelium requires nucleic acid removal and sterilization for safety concern, which might induce structural changes including protein loss, polysaccharide enrichment, and potential thermal denaturation, therefore compromising its interfacial performance. Accordingly, this work systematically evaluated the impact of sequential processing on the functionalities of F. venenatum, with the protein content consistently decreased from 50.96% in the untreated group to 43.47% in the sterilized group. Atomic force microscopy revealed that native mycelium (MB) exhibited a smooth, intact morphology with uniform nanomechanical properties, whereas processed samples showed progressive surface roughening, structural flattening, and an increased mechanical heterogeneity. These structural and mechanical alterations directly influenced the interfacial behavior, where MB demonstrated superior interfacial activity by rapidly adsorbing to form a robust elastic layer with an equilibrium tension as low as 19.12 mN/m, while sterilized samples exhibited insufficient interfacial activity (20.13 mM/m). Consequently, MB-stabilized emulsions maintained exceptional stability across diverse environmental challenges, including 28-d storage, thermal treatment (up to 120 °C), and ionic strengths (up to 400 mM). However, sterilized mycelium most susceptible to coalescence, while nucleic acid-removed mycelium retained adequate functionality at elevated concentrations, achieving a minimum droplet size of 1.03 μm at 3% concentration. The findings revealed the inherent balance between food safety requirements and functional performance, providing a rational framework for optimizing downstream conditions to preserve emulsifying functionality of F. venenatum, and for developing of mycelium with lower nucleic acid content.