Structural remodeling of myofibrillar protein by Mesona blumes polysaccharide: Effects on multi-scale structure and...

Myofibrillar protein, crucial for meat texture and quality due to its gelling properties, tends to denature during processing. While polysaccharides, particularly anionic types, can enhance its function via intermolecular interactions, current studies lack multi-scale mechanistic insights. This study investigated the structural remodeling of myofibrillar protein by Mesona blumes polysaccharide (MBPs) with different uronic acid levels and its regulatory effects on the structure and properties of the protein. The results showed that uronic acid structure of MBPs was the key to inducing conformational rearrangement of myofibrillar proteins, as MBPs with high uronic acid content endowed MP with more hydrogen bonds and hydrophobic interactions, by reducing its α-helix content by 64.8%, increasing its β-sheet content by 59.8%, and significantly decreasing its surface hydrophobicity by 13.7%. These changes further promoted the formation of a more uniform and denser three-dimensional gel network. Molecular dynamics simulations also indicated that polysaccharides altered the conformation of myofibrillar protein, thereby giving the composite system superior structural stability and rigidity. This structural transformation enhanced the gel strength of composite gels by 312.5%, increased water-holding capacity by 15.2%, and significantly improved freeze-thaw stability. The dense network structure also led to a 58.7% reduction in the in vitro digestibility of myofibrillar protein. This work provides a theoretical basis for precise application of natural polysaccharides in meat products, with potential applications in personalized nutrition, texture-modified foods, and clean-label functional products.