A SIMPLE SPECTROPHOTOMETRIC METHOD FOR QUANTIFICATION OF CASEIN IN MILK AND MILK PRODUCTS

In the food industry, production processes and food products are subjected to the highest possible quality control requirements. In order to safeguard the quality of a certain product along the production chain, it is important to know its composition. This, for instance, especially applies to a natural product like milk and its further processing in order to efficiently control the production of cheese and quark. Milk contains an important natural protein that is responsible for the essential curdling process during the production of cheese: casein. Casein protein provides the body with all the amino acids necessary to help build muscle. Casein protein is digested more slowly than other proteins, so it might be better at reducing appetite and increasing feeling of fullness. Effective control of the production processes of dairy products only becomes possible when the casein concentration is known. In this experiment casein content in milk and curd samples was determined at 524.5nm in visible range against biuret reagent by using simple uv-visible spectrophotometer. The curd and milk samples were collected from the local market. For quantitative determination of casein in milk and curd, classic protein analysis method was used i.e. biuret method. This method is based on biuret reaction in which colored copper based complex was formed. The casein protein concentration in curd sample was found to be 1684ppm. The concentration in milk sample 1 was found to be 2893ppm and in milk sample 2 was found to be 1522ppm.