Induction heating by magnetic microbeads for pasteurization of liquid whole eggs

It is a challenge to pasteurize higher-viscosity and heat-sensitive foodstuffs via traditional convective heat transfer. Herein, we demonstrate the potential application of magnetic induction heating (MIH) as a novel uniform heating method applied in the pasteurization of liquid whole eggs (LWEs). Upon exposure to an alternating magnetic field (AMF), the magnetic microbeads with a large size (50 μm) generated heat via the magnetic hysteresis effect, providing accurate and homogeneous heating due to the high specific absorption rate (SAR) of 3108.4 ± 30.6 W/(g Fe) and a homogeneous particle dispersion in high-viscosity food media. A 7.6 log reduction of Salmonella Enteritidis could be achieved in LWEs treated by MIH at 68 °C and 60 s, which was comparable to the inactivation performance of the convective heating protocol at 60 °C and 210 s (6.0 log reduction). Importantly, MIH showed a critical temperature-time regime to prevent the coagulation of egg proteins, thus maintaining the quality attributes associated with fresh LWEs. The obtained results suggested that MIH could be a potential alternative to conventional convective heating for pasteurization applications.