Kappa-Casein in Milk An Immunochemical Investigation of the ϰ-Casein Content in Milk From Danish Cattle Breeds

Mariann Thymann
1972 Acta Veterinaria Scandinavica  
THYMANN, MARIANN: Kappa-casein in milk. An immunochemical in vestigation of the ;<.-casein content in milk from Danish cattle breeds. Acta vet. scand. 1972, 13, 539-553. -The x-casein content in milk from the Danish cattle breeds SDM, RDM and Jersey was investigated by means of immunoquantitation in antibody containing agarose gels. The method, which determines the total x-casein complex, is suitable for routine work. The reproducibility of the method was found to be ± 4.1 % . The x-casein
more » ... . The x-casein concentration, expressed as percentage of the total protein content in milk, was significantly lower in milk from SDM (21.5 %) and RDM (21.3 %) than in Jersey (23.9 %). The investigation showed that the x-casein constitutes a greater part of the protein in milk than previously assumed. The amount of x-casetn was positively correlated with the protein content in milk, but there was no relation between the relative x-casein content and the percentage of fat , milk yield and the time after calving. kappa-casein; milk; cattle; immunoquantitation. Approx. 80 % of the protein in bovine milk is casein, present as a stable suspension of aggregates of calcium-proteinate-phosphate, the micelles. The casein itself is a complex mixture of several components, which were separated into IX-, and y-casein by Mellander (1939) . Later it was shown by Waugh & von Hippel (1956) that «-casein is composed of a calcium-sensitive part, IXs-casein and a soluble part, x-caseln. A complete separation of the 20 components, which constitute whole casein, was first ob-
doi:10.1186/bf03547159 fatcat:3kggfohnirh75ktx4f3xc3zfre