Advantages of Microwave and Radio Frequency Processing

Microwave and radio frequency heating for pasteurization and sterilization are preferred to the conventional heating for the primary reason that they are rapid and therefore require less time to come up to the desired process temperature. This is particularly true for solid and semisolid foods that depend on the slow thermal diffusion process in conventional heating. They can approach the benefits of high temperature/short time (HTST) processing whereby bacterial destruction is achieved, but thermal degradation of the desired components is reduced. This is illustrated in Figure 1.3.2.6 for typical time-temperature histories of microwave and conventional heated processes.

Microwave and radio frequency heating may be relatively more uniform than conventional heating. The conventional heat process shows a much larger spread of F0, which primarily signifies its tremendous nonuniformity of temperatures and long processing times leading to significant over-processing of the surface regions of the food.depend- ing on the particular heating situation (Datta and Hu 1992).

Other advantages of microwave and radio frequency heating systems are that they can be turned on or off instantly, and the product can be pasteurized after being packaged. Microwave and radio frequency processing systems also can be more energy efficient (US FDA, 2015).

The energy absorption from microwaves and radio frequency can raise the temperature of the food high enough to inactivate microorganisms for effective pasteurization

Quality parameters for microwave and conventional heating compared using computed values for typical heating situations. F represents the accumulated lethality. (Datta and Hu, 1992.)

Figure 1.3.2.6 Quality parameters for microwave and conventional heating compared using computed values for typical heating situations. F0 represents the accumulated lethality. (Datta and Hu, 1992.)

or sterilization. A number of studies have proven that the thermal effect is the essential contributor to the destruction of microorganisms (Goldblith and Wang 1967; Rosen 1972; Fujikawa et al., 1992) as well as the degradation of vitamin Bb thiamin (Welt and Tong 1993).

 
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