Heating affects gelation properties and casein micelle structure in goat and cow milk differently

Caseins play a crucial role in the gelation of milk. Heat treatment causes structural changes of the casein micelle, and hence also affects gelation properties. However, effects of heating differ between goat and cow milk, which is not well understood. This study provides a comprehensive comparison of heat-induced changes in acid and rennet gel properties of goat and cow milk from a rheological and compositional point of view. In addition, the heat-induced changes of the casein micelle structure were studied using small-angle neutron scattering (SANS). Greater changes in scattering upon heating were observed for cow casein micelles, indicating that the casein micelle structure is affected differently upon heating in cow than goat milk. This may explain why goat milk gelation properties are less affected upon heating. This work thereby presents novel insights into differences of goat and cow casein micelles and their functional properties after heat treatment. The knowledge is valuable to modify and justify changes of industrial processes for products made from goat milk. • Gelation properties are more affected by heat-treatment in cow than goat milk • Great changes in serum and gel protein distribution upon heating in cow milk • Goat casein micelle structure is less affected upon heating than cow casein • Heat-induced changes of gelation are associated with changes in micelle structure