Coacervates assembled by liquid-liquid phase separation as binders for improving the quality of Fusarium venenatum-based meat analogues

The inherent filamentous fiber structure of Fusarium venenatum makes it a promising candidate for meat analogues. However, the rigid cell wall structure results in undesirable textural properties in the final product, highlighting the necessity of a suitable binder for quality improvement. In this study, 7S vicilin and chitosan oligosaccharide (COS) at a mixing ratio of 10:1 and pH 5.5 formed liquid-like coacervate with superior viscoelasticity and strong interfacial wettability, making it suitable for binder design. In contrast, pea protein isolates and COS underwent liquid-solid phase separation (LSPS) and produced an irreversible precipitate that lacking binding functionality. Unlike LSPS, liquid-like coacervate relied on weak multivalent interactions across numerous binding sites and were characterized by a distinctive spherical droplet morphology, leading to enhanced interfacial adhesion and structural flexibility. When applied to mycoprotein-based meat analogues, the optimized binder significantly reduced cooking loss to 21.65%, compared with 29.28% for the methylcellulose-based control. Concurrently, textural properties including hardness and chewiness were markedly enhanced in the meat analogues prepared with liquid-like coacervate binder, suggesting the generation of a compact and tough protein network. Overall, this study established a functional liquid-like coacervate system, offering a viable, green, and clean-label alternative to synthetic binders for the development of high-quality meat analogues.