Cyclic microwave thawing of frozen meat: experimental and theoretical investigation

Experimental and theoretical investigation of microwave thawing of frozen m inced beef is conducted. The main objective is to develop a theoretical mod el to predict temperature distribution in frozen meat samples of different thickness, when subjected to a microwave cyclic heating. The experiments sh ow that thawing process starts from the surface of the sample and progresse s slowly down to the bottom, which is due to the strong absorption of micro wave at positions close to surface. The computer model is based on a moving boundary model, developed previously for melting and solidification of pha se change materials. Thawing is assumed to occur within a range of temperat ures, which is true for meat and most food materials. An effective heat cap acity is used in the mushy region to represent the latent heat effect. Reas onable agreement is found between the experimental measurements and model p redictions. Results show that it is possible to thaw the meat under control led conditions such that its surface temperature never exceeds 10 degreesC. Thawing time is found to be less than one-fifth of that required in conven tional thawing. (C) 2001 Elsevier Science B.V. All rights reserved.