Thermal gelling properties and mechanism of porcine myofibrillar protein containing flaxseed gum at different NaCl concentrations

•FG addition in MP gels enhanced the WHC at different NaCl concentrations.•Salt addition from 0.3 to 0.6M significantly influenced the gel strength of MP-FG.•FG promoted a more dense gel network of MP-FG gels by electrostatic interactions.•FG induced the partial transformation of α-helices into β-sheets in MP-FG gels.•FG may reduce the amount of salt used in meat products which were sensitive to salt.

This study aimed to investigate the thermal gelling properties of porcine myofibrillar protein (MP) containing flaxseed gum (FG) at different NaCl concentrations. In this work, MP-FG gels with 0.4% FG were prepared with varying NaCl concentrations (0.2-0.6 M). FG enhanced the water holding capacity (WHC) and decreased the gel strength of MP sols at different NaCl concentrations. The particle size of the MP gels increased with FG addition at a low NaCl concentration (0.2 M) but decreased under a high NaCl concentration. Dynamic rheological tests proved that the storage modulus and gelation rates of MP-FG gels were lower than those of MP gels. FG induced the partial transformation of α-helices into β-sheets in the gels under different NaCl concentrations. Scanning electron microscopy images revealed that the MP-FG network became more compact with increasing NaCl concentration. These results provide novel insights into the structural-functional relationships of MP-FG gels at different NaCl concentrations.