Effects of homogenization and heat treatments on whey protein composition of bovine, buffalo, goat, camel and yak milk

Milk whey proteins are sensitive to heat processing; however, differences in the whey proteome across various species following homogenization and heat treatment remain inadequately understood. This study aimed to examine changes in the abundance of whey proteins in milk from five species after homogenization (50°C, 20 MPa) and heat treatment (63°C/30 min and 90°C/15 min) using an LC-MS/MS approach. A total of 759 proteins were identified and quantified in raw and treated milk. Homogenization and heat treatment affected the abundance of fatty acid-binding protein 3, apolipoprotein A-I, lactoperoxidase, and lactoferrin, with species-specific variations depending on the heat intensity. Notably, after homogenization and 63°C for 30 min treatment, lactoferrin abundance decreased in cow (6.2- and 6.4-fold) and goat (1.8- and 1.5-fold) milk whey, while no significant changes were observed in buffalo, camel, and yak milk. Additionally, the dissociation of caseins in whey fractions varied by species. In goat milk, the abundances of β-casein, κ-casein, α- S1 -casein, and α- S2 -casein increased, indicating a higher sensitivity to heat treatment, whereas in camel milk, only κ-casein increased. These findings highlight that variation in the milk whey proteome, influenced by both species-specific differences and processing-induced changes, contribute to the optimization of dairy processing techniques, warranting further investigation. • κ-casein and α- S1 -casein increased in goat milk whey after homogenization and heat. • Lactoferrin decreased in homogenized and 63°C/30 min heated cow and goat milk. • Apolipoprotein AI decreased in homogenized and 63°C/30 min heated all studied milk. • Changes in lactoperoxidase and lactadherin related to specific milk and processing.