Effects of pulsed electric field (PEF) and oscillating magnetic field (OMF) on supercooling preservation of beef at different fat levels

Supercooling is of particular interest in the food industry since it has a great potential to improve shelf-life without freezing damage during storage. Food is a complex matrix of multi-components and its supercooling behavior may depend upon the physical properties of each component. In this study, the effect of a pulsed electric field (PEF) and an oscillating magnetic field (OMF) on supercooling of beef at different fat levels were explored. Lean-rich beef was supercooled with PEF only, while the simultaneous application of PEF and OMF was required for fat-rich beef. The finite element method (FEM) simulation demonstrated that fat caused the non-uniform current flow and temperature gradient due to the low electrical conductivity, and subsequently negative impacts on the supercooling extension of fat-rich beef meat. The OMF combined with PEF ensured maintaining a supercooled state of fat-rich beef at -4 degrees C by synergistically inhibiting ice nucleation. The beef steaks preserved in the supercooled state showed significantly lower drip loss, compared to the conventionally stored controls, and there were no significant differences in color between supercooled and fresh steaks during the 7 day-preservation.