Superoxide Dismutase Activity in Intact, Extracted, or Calcium Depleted Raw Cow Milk

Dragana Filipović, Jelena Kasapović, Snežana Pejić, Ana Nićiforović, Snežana B. Pajović, and Marija B. Radojčić

Laboratory of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro

Corresponding author: Marija B.Radojčić, Ph.D., Res.Assoc.
    Laboratory of Molecular Biology and Endocrinology
    VINČA Institute of Nuclear Sciences
    P.O. Box 522-MBE090
    11001 Belgrade, Serbia and Montenegro
    Telephone: +381 (11) 245-55-61
    Fax number: +381 (11) 245-55-61
    E-mail: marija@vin.bg.ac.yu

CEJOEM 2003, Vol.9. No.4.: 284–289


Key words:
Raw cow milk, casein, SOD activity, milk quality


Abstract:
Milk is a polyphasic secretion of the mammary gland with significant antioxidant activity and high calcium content bound by protein micelles. The relationship between the antioxidant activity and the structural organization of milk proteins is not well understood. The present study deals with the structure of milk proteins and its relation with the superoxide dismutase (SOD) activity. The effects of several laboratory treatments on the sodium dodecylsulfate polyacrylamide gel elecrophoresis (SDS-PAGE) profile of the protein, and on the respective SOD activity were studied in raw milk samples from IMPAZ Co, Zaječar, Serbia. In all samples, SOD activities in the range from 2 to 3 U/mg protein were detected. It could be purified up to 5 U/mg protein. The removal of calcium caused disruption of casein micelles and significant decrease in SOD activity to 1.24-0.18 U/mg protein. It is concluded that the high antioxidant content of the initial raw milk, as well as the technology of its processing are of great importance for the preservation of SOD activity in the final foodstuff product.


Received: 31 July 2003
Accepted: 5 December 2003

| Back |