Effect of different treatments on the stability of lysozyme, lactoferrin and β‐lactoglobulin in donkey's milk

The aim of this study was to investigate the effects of freezing and heat treatments at different temperatures on the stability of the main whey proteins of donkey milk in comparison with those obtained from colostrum and raw milk. Samples subjected to heat treatment at 85 °C showed greater loss of stability, with levels decreasing by 60% and 87% for lysozyme and β‐lactoglobulin, respectively. Lactoferrin completely disappeared at heat treatments higher than 65 °C. Colostrum contained the highest lactoferrin and β‐lactoglobulin concentrations, however, lysozyme was found to be present at similar concentrations in colostrum, raw, frozen and heat‐treated milk at temperatures lower than 85 °C.