Abstract:
Temperatures and electric conductivities of granule center and liquid phase of liquid food materials with fruit granule were examined, respectively, with a self-designed testing system. Temperature changing laws of various solid-liquid mixing food materials, during Ohmic heating, were concluded, as well as corresponding electric conductivities of their liquid phases and solid phases. Electric conductivities of liquid phase and solid phase of materials and their different alterations, in the procedure of heating, are major causes for the development of non-uniform temperature field. While food material is heated in the apparatus, its temperature distribution is also influenced to some degree by tube walls of heating apparatus, heat diffusion of in-feed and partial over-heat near electrode plates. These experimental results can provide valuable information for deeper researches on Ohmic heating properties of liquid food with granule as well as developing practical Ohmic heating apparatus and high quality food with granule.