Bimodal Method of Determining Fat and Salt Content in Beef Products by Microwave Techniques

A bimodal microwave technique is presented as a rapid analytical method of estimating the fat and salt content of beef products. The dielectric properties of lean meat, fat, salt, and other nonmeat ingredients (dry and aqueous solutions) and meat blends of typical ingredients used in meat product manufacture are all separately investigated. A broadband coaxial probe technique is used to select frequencies of maximum sensitivity. The optimum frequency for fat determination lies between 8 and 20 GHz, and the optimum frequency for salt determination lies below 4 GHz. For example, by using a WR-90 cell, either the real or imaginary part of the complex permittivity can effectively resolve fat content, whereas the imaginary part of the permittivity correlates well with salt content when using a WR-284 cell. The technique is sufficiently robust to ensure that the dielectric effects of other nonmeat ingredients, temperature, and density do not adversely affect this measurement approach.