Broadband dielectric properties of honey: effects of temperature

Dielectric properties of jujube honey were investigated at 298-358 K by broadband dielectric measurements. Four relaxation processes were observed and analyzed, which are caused by long range correlation of density fluctuation, cooperative motions of molecules, rotational polarization of bound water and collective reorientation of free water, respectively. The results of temperature dependence of dielectric parameters show that with increasing temperature, the interaction among the molecules e.g. water, fructose and glucose molecules etc. weaken, and the honey gradually forms a complete sugar solution. At a given temperature, the penetration depth at 27 MHz is much greater than that at 915 MHz and 2.45 GHz. And based on the calculated penetration depth, dielectric heating at 27 MHz seems to has more advantages for large volume of materials.