COMPARISON OF METHODS FOR DETERMINING THE FALSIFICATION OF MILK
Falsification of milk creates many difficulties in the dairy industry. Diluting milk with water can cause changes in the chemical composition, nutritional, hygienic and technological quality of milk. The aim of this study was to evaluate the possibility of applying the standard method for milk analysis for determining the presence of added water in sterilized milk products. Samples were prepared by diluting the milk with distilled water in the range from 5 to 50%, with a gradient of 5% and monitoring the impact of water on the relevant physical and chemical indicators of milk. Standard methods for milk analysis were performed, such as: determination of fat content, density, viscosity, acidity and sensory evaluation. Analysis of milk samples prepared with the proper dilution has shown that the average value of the freezing point of the milk samples ranged from -0.484 0C to -0.25 0C. Determination of the fat content showed that the fat content was constantly decreasing, from 3% (5% H2O) to 1.48% (50% H2O). With the increased proportion of water in milk, the density and viscosity were reduced, and pH value was slightly increased. Sensory evaluation was only partially accurate. In addition to cryoscopy, as a reliable method for determining the presence of added water in milk, some other methods have also proven to be reliable, such as: determination of fat content, density, viscosity and acidity.
Milk falsification, Raw milk, Cryoscopy.