Revealing the entanglement between pectin and silver carp myofibrillar protein molecular chains: A new perspective on the effect of solubilization mode on gel properties

Abstract

This study investigated the structural and functional properties of composite gel systems formed by myofibrillar protein (MP) and apple pectin (AP) in both powder and solution forms under various treatment conditions. The results indicated that AP powder, compared to AP solution, was more effective in facilitating the partial unfolding of MP, thereby exposing reactive sulfhydryl and hydrophobic groups. This led to tighter chain entanglements and the formation of larger particle aggregates. During the dissolution process, AP powder created more opportunities for localized interactions, acting as a “bridge” that promoted the transition of MP from a disordered aggregated state to an ordered chain structure, while enhancing inter-chain entanglements with MP and further strengthening intermolecular interactions. Furthermore, AP powder formed stronger cross-links with alkaline-pretreated MP, significantly reducing the flexibility of MP molecular chains. Rheological analysis revealed that the addition of AP powder increased the cross-linking density within the MP gel network, thereby enhancing its mechanical strength. By introducing more physical entanglements, it optimized the overall gel performance. In summary, this study provides a theoretical foundation for the development of high-performance food gel systems.