2. Materials and methods2.1. Milk s

2. Materials and methods
2.1. Milk samples

Camel milk was collected from reared camels by been directly milked into a sterile milking can. The camel milk used was pooled milk samples assembled from 20 different healthy camels (Camelus dromedarius) that ranged between 2 and 12 months in lactation. Cow milk was collected from 20 different Holstein cows. Both milk samples were derived from a local breeding located in the south of Tunisia. The milk samples were immediately transported to our laboratory using an ice box within 4 h. Once reaching the laboratory at 4 °C, pH (744-pH meter, Metrohm SA CH-9101, Herisau, Switzerland) was determined. Subsequently, both milks were skimmed by centrifugation at 3000g during 20 min at 4 °C (Gyrozen 1580MGR, Multi-purpose Centrifuge, Daejeon, Korea).