Effect of chitosan on thermal gelling properties of pork myofibrillar protein and its mechanism.

Background: Previous studies have demonstrated that the addition of chitosan can improve the quality and functional properties of meat products. However, the underlying mechanism remains unclear. In this study, the effect and mechanism of the addition of chitosan on the gel properties of myofibrillar protein (MP) were investigated.

Results: The results indicated that the gel strength and the water-holding capacity of MP-chitosan gel increased significantly when chitosan was added at 2.5-10 mg mL^-1. Myofibrillar protein samples with 10 mg mL^-1 added chitosan exhibited the highest elasticity and viscosity during gel formation and strengthening. The addition of chitosan also caused a modification in both the secondary and tertiary structure of MP, resulting in an enhanced exposure of hydrophobic and sulfhydryl groups in comparison with the control. Chitosan inhibited the conversion of immobilized water into free water and the formation of water channels during the thermal gelation process of MP. The denaturation enthalpy (ΔH) of myosin decreased as the concentration of chitosan exceeded 5 mg mL^-1. The microstructure showed that the incorporation of chitosan (5-10 mg mL^-1) facilitated the formation of compact and well organized MP gel networks.

Conclusion: The addition of chitosan can enhance the functional properties of meat protein and facilitate heat-induced gelation, making it a promising ingredient for improving the quality of processed meat products. © 2024 Society of Chemical Industry.