Heat stability characteristics of ovine, caprine and equine milks

Summary Ovine and caprine milks showed a marked stability maximum at ~ pH7 in their heat-stability/pH curves, but became very unstable at higher pH values. A low level of κ-casein appears to be responsible for this low stability of ovine milk; β-lactoglobulin offsets the stabilizing influence of κ-casein at lower pH values. Removal of colloidal calcium phosphate from ovine or caprine milks had very little influence on their heat stabilities and it was necessary to reduce the concentration of soluble salts to a very low level before an effect was observed. At the pH of maximum stability ovine and caprine milks, although quite variable, had stabilities in the same range as bovine milks. Equine milk was very unstable to heat and the shape of the heat-stability/pH curve of most individual samples was similar to ovine and caprine milks.