Potentiometric Method for Detection of Raw Milk Components

Rapid analysis of milk components is often necessary in clinical settings, biotechnology, the food industry, and animal husbandry. Existing data on the possibility of analyzing milk through a correlation between lactose and mineral concentrations remain contradictory and require further verification. This study examines a possible correlation between the electromotive force (EMF) readings of ion-selective electrodes and lactose in raw cow's milk. A laboratory setup with an ion meter-conductometer-thermometer equipped with a potassium-selective electrode, a heated magnetic stirrer, and ultrasonic and viscometric milk quality analyzers was used to collect measurements of various milk parameters. Milk with the following parameters was used: fat content (from 2.59% to 4.49%), protein content (from 3.01% to 3.72%), and lactose (from 4.11% to 5.11%). As a result, it was found that changing the temperature from 30 °C to 39 °C leads to a 3-5% decrease in the generated EMF of a milk sample. The EMF decrease occurs differently for milk with different combinations of quality parameters. A statistically significant strong linear relationship of r = 0.88 at p < 0.05 was established, as well as a determination coefficient of R2 = 0.77 between lactose content and EMF in milk. This result opens the possibility of rapid analysis of milk using potentiometric methods.