Digestibility of proteins in camel milk in comparison to bovine and human milk using an in vitro infant gastrointestinal digestion system

•First study of camel milk protein digestibility under infant digestion conditions.•Camel, bovine and human milk protein digestibility was compared.•Camel milk whey proteins were more easily digested under infant gastric conditions.•The ionic environment of milk plays a critical role in its gastric coagulation.•Multiple novel and potential bioactive peptides were found in the camel milk digesta. The absence of β-lactoglobulin, high β-/αs-casein ratio and protective proteins make camel milk a promising alternative protein base for making human infant formulae. In this study, protein digestibility of camel milk was compared with that of bovine and human milk using an in vitro infant gastrointestinal digestion system. A low degree of gastric proteolysis was observed in all three kinds of milk, and a single clot was formed in camel milk. The soluble milk proteins remaining in the gastric digesta were digested rapidly and extensively in the intestinal phase, while the proteins in the camel milk clot were hydrolysed gradually. Despite several similarities, bioactive peptides unique to individual milk were identified in the three intestinal milk digesta. The results suggest that camel milk proteins are equally digestible as bovine and human milk proteins under infant gastrointestinal digestion conditions, and it may be a prospective substitute for infant formula base.