Electronic Technique for the Determination of Added Water to Milk

Adding water to milk is a common practice by farmers. It leads to economic losses, deterioration of the quality of end products. In this paper the technique of ac conductance spectroscopy has been used to study the milk samples having different proportions of added water in full fat milk over the range of 20 Hz to 1 MHz. The characteristics show that the conductance exhibits a rapid variation with frequency below 10 kHz, but remains constant above this value. The conductance measured at 10 KHz frequency decrease with increasing water concentration in full fat milk, the reason for this is that the milk has conductivity properties because of the existence of charged compounds such as salts. The milk samples were also tested at 10 KHz frequency and 8 C temperatures by using simple electronic circuit. The result indicates that the output voltage decreases with increase in percentage of added water to milk. This measurement technique may be used for the development of a simple milk quality testing instrument.