Structural changes induced by direct current magnetic field improve water holding capacity of pork myofibrillar protein gels

The study was to investigate the role of direct current magnetic field (DC-MF) for water-holding capacity (WHC) of myofibrillar protein gels and to understand potential mechanisms. Samples were subjected to DC-MF with different intensities (3.5, 3.8, 9.5 and 10.4 mT), and DC-MF treatment significantly improved WHC compared with control (46.09%), reaching the maximum value of 50.36% at 3.8 mT. The main reason for the increase in WHC might be that DC-MF modified the protein structure via unfolding, re-crosslinking and aggregation of proteins, which was supported by the increased intensity of tyrosine, aliphatic and tryptophan residues, and reduced reactive sulfhydryl (2.97 to 1.94). And the re-crosslinking between molecules was maintained mainly through hydrophobic interactions and disulfide bonds. Besides, DC-MF treatment helped to generate a relatively loose and uniform microstructure to trap more water as shown by electron microscope image, which was consistent with the highest WHC at 3.8 mT.

Automated summary

The study demonstrates that direct current magnetic field treatment significantly enhances the water-holding capacity of myofibrillar protein gels, possibly by altering protein structure and intermolecular re-crosslinking. The treated samples exhibit a relatively loose and uniform microstructure post-treatment, facilitating more water trapping.