Optimization of radio frequency heating of in-shell eggs through finite element modeling and experimental trials

Considering Radio Frequency (RF) heating as a viable alternative for the in-shell heating of eggs, Finite Element Modeling and simulation of RF heating of in-shell eggs at 27.12MHz were carried out to assess the feasibility and heating uniformity of the process. According to the recommendations of USDA-FSIS for the pasteurization of eggs, egg white must be heated up to 57.5°C, and the egg yolk has to be heated up to 61.1°C for 2 min. The objective of the simulation was to determine the location of hot and cold spots generated due to non-uniform heating. A parallel plate setup for Radio Frequency heating was simulated for different electric field strength levels and orientations of the egg (long axis parallel and long axis perpendicular to the plates). The simulation results were experimentally verified and the simulation procedure was validated using a laboratory parallel plate RF setup. A coaxial cavity design was simulated with a similar approach. Results indicated that both the parallel and coaxial cavity designs were suitable for in-shell pasteurization of eggs provided that the eggs were rotated to maintain the uniformity in heating. After the simulation of RF heating process, the process optimization was carried out to determine the most effective procedure for the process. The varying parameters obtained by using different modeling techniques for radiofrequency heating of in-shell eggs, were optimized using MATLAB. Laboratory scale experimental trials were conducted to test the validity and effectiveness of the optimized parameters. The optimal parameters set forth were found to be more efficient in terms of heating time and uniformity.