Interactions between myofibrillar protein and konjac glucomannan at critical thermal phase transition temperatures: Aggregation, cross-linking, and protein conformational changes

This study investigated the gelling properties and thermal resistance of a composite system comprising myofibrillar protein (MP) and konjac glucomannan (KG). The interactions between the two components at critical phase transition temperatures (44 °C and 55 °C) were analyzed using rheology, thermodynamics, dynamic light scattering, spectroscopy, and microscopic imaging. The results revealed the dynamic evolutions in aggregation, cross-linking, and protein conformation. The blended gels exhibited high cross-linking densities and well-ordered macromolecular aggregation patterns. At critical phase transition temperatures, KG promoted the unfolding of MP molecules and the formation of microstructural domains, enhancing the exposure of hydrophobic groups and reactive sites. The cross-linking behavior at 55 °C, dominated by disulfide bonds and hydrophobic interactions, further strengthened intermolecular interactions, forming compact gel networks predominantly stabilized by β-sheet structures. In addition, KG improved the conformational stability of the MP molecules and compensated for structural defects in the single-phase gel matrix. These crucial enhancements induced elevated gelling capabilities, which contributed to the formation and stabilization of the gel networks, ultimately yielding excellent hydration, textural, and thermodynamic properties. These insights will facilitate the preparation of composite gels with particular structures and modifications, as well as the utilization of KG for precise regulation during the thermal processing of meat products.