Dielectric properties of process cheese from 0.3 to 3 GHz

Dielectric properties of 16 process cheeses were determined over the frequency range 0.3–3 GHz. The effect of temperature on the dielectric properties of process cheeses were investigated at temperature intervals of 10 °C between 5 and 85 °C. Results showed that the dielectric constant (ε′) decreased gradually as frequency increased, for all cheeses. The dielectric loss factor (ε″) decreased from above 125 to below 12 as frequency increased. ε′ was highest at 5 °C and generally decreased up to a temperature between 55 and 75 °C. ε″ generally increased with increasing temperature for high and medium moisture/fat ratio cheeses. ε″ decreased with temperature between 5 and 55 °C and then increased, for low moisture/fat ratio cheese. Partial least square regression models indicated that ε′ and ε″ could be used as a quality control screening application to measure moisture content and inorganic salt content of process cheese, respectively.