Application of Research Methodologies in Dairy Chemistry

Milk is a complex food consisting of numerous constituents, mainly water, fat, protein, lactose, and minerals. All the constituents have different chemical structures and properties. There are various techniques available to identify the constituents both qualitatively and quantitatively. The common techniques used are chromatography, spectroscopy, electrophoresis method, supercritical fluid extraction, immunoassay, and thermal analysis. Chromatography is a separation of molecules between two different phases: mobile phase and stationary phase. It is a fast, accurate, and sensible method. Spectroscopy is the study of the interaction of the light with the material. The movement of a charged molecule in an electric field is electrophoresis. Supercritical fluid extraction is a separation technique used as a preliminary step for the isolation. Antigen and antibody interaction is the basis of immunoassay. Thermal analysis detects the physicochemical change due to exposure of temperature. Chromatography, spectroscopy, and thermal analysis methods can detect the major constituents of milk and milk products, i.e., proteins, fat, vitamins, and lactose. Minerals are generally detected by atomic absorption spectroscopy. Electrophoresis differentiates the milk proteins, and immunoassay is used to detect pesticide, antibiotics, and microbes including pathogens.