Investigation of dielectric properties of varieties of milk powder at various frequencies

Abstract

The dielectric properties of a material determine its response of the material to the Electromagnetic field (EM field). It comprises dielectric constant ([Formula: see text]), which is the ability to store energy of EM fields, and dielectric loss ([Formula: see text]) which is the amount of dissipated Electromagnetic energy in the form of heat. Dielectric properties are affected by various factors such as frequency, temperature, bulk density, moisture content, etc. Dielectric constant and dielectric loss were determined in this study for milk powders viz. Whole Milk Powder, Skim Milk Powder, and Infant Milk Powder at various microwave frequencies (5.68, 7.45, 10.25[Formula: see text]GHz). The method used to determine dielectric properties is the Two-point Method which is implemented on a microwave bench. It became apparent that when frequency increases dielectric constant decreases and dielectric loss first decreases and then increases. It was also observed that the fat content can have an impact on the milk powders’ dielectric properties.