Electrophoretic Identification of Casein in Various Types of Milk

Abstract

Casein proteins of camel milk were obtained from skimmed milk by sedimentation (pH 4.6) at 24°C. To sediment proteins from mare milk, pH was increased to 4.6 and milk was centrifuged at 45,000 rpm for 30 minutes at 4°C. The supernatant obtained after centrifugation was heated up to 30°C for further fractionation of whey proteins. The sedimented casein from camel and mare milk was cleaned with chromatography. Casein fractions were analyzed with the use of electrophoresis based on SDS-Na polyacrylamide. This analysis showed the presence of α- , β- and κ-caseins, as well as fractions of whey proteins, such as α-lactalbumin and β-lactoglobulin in various types of milk and fermented products. Comparative study by the content of protein component of the casein complex in camel milk showed the following: αs-casein 31.5%, β-casein 64.5%, κ-casein 4%, in cow milk 40.12%, 24.28%, 27.93%, respectively and γ-casein amounts to 7.67%.