Effect of low-frequency alternating magnetic field on the conformational, rheological and gel properties of low-salt porcine myofibrillar protein

In this research, low-frequency alternating magnetic field (LF-AMF, 5 mT, 1-5 h) was used to investigate the effect on the structural, rheological, and gel properties of porcine myofibrillar protein (MP) under low-salt condition (0.3 M NaCl). The solubility, surface hydrophobicity, active sulfhydryl content, intrinsic fluorescence intensity, water holding capacity (WHC), and gel strength of low-salt porcine MP exhibited a trend of initial increase followed by a subsequent decrease as the LF-AMF processing time extended (P < 0.05). Furthermore, LF-AMF treatment could induce an elevated β-sheet proportion, G' value and a reduced α-helix proportion, suggesting that LF-AMF facilitated the improvement of gel attributes in low-salt porcine MP. Meanwhile, LF-AMF could trigger the construction of a homogeneous and tight MP gel network, resulting in bounding of more water molecules, which elevated the percentage of immobilized water and diminished the percentage of free water. Thus, an appropriate LF-AMF processing time can effectively improve the gel characteristics of low-salt porcine MP.