Freeze dehydration by microwave energy: Part II. Experimental study

Experimental drying curves have been obtained for the freeze‐dehydration of beef meat with microwave energy at 2450 MHz. In particular, experiments conducted with slabs of raw beef meat approximately 1.5 cm thick show that total drying times of less than 6 hr. can be obtained. Further drying time reductions are possible if microwave heating and freezing techniques are improved. Samples can be dried slightly faster at a higher pressure (for example, 1 mmHg) than at a lower pressure (for example, 0.2 mmHg) for the same microwave power input. However, melt back and vaporization occur if the pressure or the microwave power input is too high. Comparison of the experimental drying curves with those predicted by the theory shows a reasonable agreement which, at least in part, verifies the validity of the previously derived mathematical model.