Characterization of Arabian camel milk proteome over lactation

The World Health Organization recommends that infants be exclusively breastfed for the first 6 months of life for their optimal growth and health. However, less than 35% of infants worldwide even complete breastfeeding for more than 4 months [1]. Infant formula is intended as a substitute to breast milk and it is formulated to mimic nutritional composition of breast milk using bovine milk as protein source [2]. However, hypersensitivity to bovine milk proteins (mainly to αs1-casein and β-lactoglobulin) is one of the major food allergy affecting between 2% and 3% of the general child population [3]. In recent years, camel milk is getting attention due to its reported lower αs1-casein content compared with cow milk and the absence of β-lactoglobulin that may be a promising new protein source for children allergic to bovine milk proteins [4]. This work aimed to characterize the proteomic profile of camel milk at two different stage of lactation. Three multiparous she-camels of the herd of Oasis Park Fuerteventura (La Lajita, Las Palmas, Spain) were milked at early (42 ± 11 DIM) and late (252 ± 15 DIM) stage of lactation for sampling collection. Milk samples protein characterization was performed through 1D and 2D-electrophoresis. Differentially expressed proteins between the two groups (early and late lactation) were identified by MALDI TOF mass spectrometry. Multivariate data analyses, including PCA, PLS-DA were used to generate an integrated vision of changes of the protein profile of camel milk over lactation. Results highlighted the presence of 7 differentially expressed proteins between two groups. These findings could be useful for a better understanding of the protein composition dynamics of camel milk.