Authors:D. Filipović, J. Kasapović, S. Pejić, A. Nićiforović, S. B. Pajović, and M. B. Radojčić
Specific composition, protein profiles and total SOD activity were analysed in full milk samples obtained from five farms of the Milk Company IMPAZ. The effects of several laboratory treatments on milk proteins SDS-PAGE profiles and the respective SOD activity were also followed. The total SOD activity was detected in all full milk samples, and its values varied between 2 and 3 U mg-1 protein. The enzyme could be partially purified, up to »5 U mg-1 protein, by ethanol extraction. The recovered SOD activity in ethanol extract was proportional to the initial full milk SOD activity. The disruption of casein micelles by Ca2+ removal was followed by a significant decrease in SOD activity to 1.24-0.18 U mg-1 protein. The loss of enzyme activity was ascribed to the changes in milk milieu induced by dissociation of casein micelles.