Dielectric properties of shrimp related to microwave frequencies: From frozen to cooked stages

Dielectric properties of shrimp (Penaeus sp.) were measured at frequencies between 0.3 and 3 GHz from -25 to 70 C by using a network analyzer. The relationship between dielectric properties and temperature was determined at 915 MHz and 2450 MHz. Below the freezing point, the dielectric constant (ε′) and dielectric loss factor (ε″) increased rapidly with increasing temperature as ratio of frozen water in shrimp was decreasing. Above the freezing point, the dielectric constant (ε′) decreased as frequency and temperature increased at both frequencies. The dielectric loss factor (ε″) did not change significantly with temperature. The relationships between penetration depth and temperature at both frequencies were evaluated from the experimental data.