Effect of temperature on the RF dielectric properties of human breast milk

The dielectric dispersion of human breast milk has been investigated by means of a resonance technique over the frequency range 0.1-100 MHz and at six temperatures from 10 to 60 degrees C. A computer analysis of the data was carried out on the basis of the Cole-Cole structural model and the fitted parameters have been presented. The dependence on temperature of both the viscosity of the human milk and its dielectric relaxation has been discussed. The heat of activation delta H of the milk, calculated in accordance with Eyring's theory of rate processes was found to be 19.5 +/- 0.6 kJ mol-1 for the dielectric relaxation process and 20.2 +/- 0.8 kJ mol-1 for viscous flow.