Detection of Adulteration in milk using capacitor sensor, with an especial focus on Electrical properties of the milk.

With the growth of population, the demand of milk is increasing at very fast rate. Due to this increasing demand, adulteration of milk by various substances has been very common in throughout the world, which not only reduces the nutritional value but also causes various diseases to human being. The common adulterants used in adulteration are detergents, ammonium sulphate [(NH₄)SO₄], sodium hydroxide (NaOH), sodium-bi-carbonate (NaHCO₃) ,common salt (NaCl) and fat.

The aim of this paper is to identify / detect the minimum detectable limit for the above six adulterants in the milk. A capacitor sensor is used, which is sensitive to an electrical property ( Relative Permittivity ) of the measuring medium and gives different dielectric loss angle of the milk sample under measurement, when sensor is immersed in different adulterated/unadulterated milk. The tangent of dielectric loss angle (tan Delta) is measured by Schering Bridge. By this sensor measurement system, detection of adulterants in milk with different % (from 5% to 20%) is studied. Packet milk and raw-milk (directly collected from the milk collection center) are used for the experiment. Experimental results of various adulteration levels are plotted for verification of the result and to check the data consistency.