LC-Q-Orbitrap HRMS-based proteomics reveals potential nutritional function of goat whey fraction

Guanzhong dairy goat milk is the product of national geographical indication exclusively in Shaanxi province of China. A total of 433 whey proteins were identified and quantified in colostrum and mature milk, which were obtained from Guanzhong dairy goat and Chinese Holstein. Twenty-seven highly expressed proteins in GM were related to immune response, and 23 were metabolic processes. Thirty-four highly expressed proteins in GC milk were mainly related to the immune response, negative regulation of endopeptidase activity and ossification, indicating that goat milk was very important for the development of immune system and bone growth and ossification in newborns. Bioinformatics analysis showed that the differentially expressed proteins in the four whey groups were mapped in 15 pathways, in which the complement and coagulation cascade and carbon metabolism were the most important. Cross-species comparison of whey protein helps to extend understanding of variation in the nutritional value of different milk sources.