Cyclic microwave thawing of frozen meat: experimental and theoretical investigation

Experimental and theoretical investigation of microwave thawing of frozen minced beef is conducted. The main objective is to develop a theoretical model to predict temperature distribution in frozen meat samples of different thickness, when subjected to a microwave cyclic heating. The experiments show that thawing process starts from the surface of the sample and progresses slowly down to the bottom, which is due to the strong absorption of microwave at positions close to surface. The computer model is based on a moving boundary model, developed previously for melting and solidification of phase change materials. Thawing is assumed to occur within a range of temperatures, which is true for meat and most food materials. An effective heat capacity is used in the mushy region to represent the latent heat effect. Reasonable agreement is found between the experimental measurements and model predictions. Results show that it is possible to thaw the meat under controlled conditions such that its surface temperature never exceeds 10°C. Thawing time is found to be less than one-fifth of that required in conventional thawing.