Impedance characteristics measurements to assess physical indicators in pasteurized milk

The knowledge of electrical properties measurements may hold a potential to develop a rapid technique for quality evaluation or determination of concentration and freshness of foods. Especially impedance characteristics measurements in a frequency range focus on unstructured food materials which do not exhibit a structure with insulating cell membranes including milk, edible oil, juice, whole egg products, or homogenized food. In this research, the impedance characteristics of UHT whole, low fat and skim milk at room temperature were investigated over the frequency range from 20 Hz to 12 MHz. The measurements were conducted with a impedance analyzer was connected to a specially constructed parallel-plate capacitor sample holder at the constant voltage 200 mV. The components in milk are decomposed into various acids and other inorganic materials with the growth of microorganisms during storage in room temperature. This works provide interesting insights aimed at developing a rapid method for determination of p