Effects of pulsed electric field (PEF) and oscillating magnetic field (OMF) combination technology on the extension of supercooling for chicken breasts

In this study, a pulsed electric field (PEF) and an oscillating magnetic field (OMF) were used to achieve an extension of a supercooled state within chicken breasts. The specifications of protocol are: (i) PEF with duty cycle sequence of 0.8, 0.5, and 0.2 were applied for 300 s, 120 s, and 90 s, respectively and (ii) during PEF with duty cycle of 0.2, OMF with 1 Hz was applied to vibrate water molecules and inhibit sudden ice nucleation. At the freezer temperature of −7 °C (±0.5), temperature of chicken breast samples under PEF and OMF treatment decreased down to −6.5 °C in a supercooling state during the whole testing period (approximately 12 h); while the control samples were partially frozendown to −6.5 °C. The impacts of the supercooling on microstructure, drip loss, color, texture, pH and lipid oxidation were evaluated as compared with samples stored at refrigeration (4 °C) and at freezing (−7 °C). It was found that the PEF + OMF supercooling was highly effective in the maintenance of original meat qualities without significant physical damages or chemical changes. The supercooling of meat samples using the developed PEF and OMF combination technique led to the advanced designing of innovative food freezers for long term preservation of 'fresh-like' foods at subzero temperature.