ACE- inhibitory and radical scavenging activities of bioactive peptides obtained from camel milk casein hydrolysis with proteinase K

The aim of this study was to evaluate the effects of enzymatic hydrolysis of camel whole casein on their antioxidant and angiotensin-converting enzyme (ACE)-inhibitory properties. Whole camel casein was hydrolyzed by proteinase K (PK), and the hydrolysates were fractionized by ultrafiltration membranes into three fractions. Semi-preparative reversed-phase high-performance liquid chromatography (RP-HPLC) was used to differentiate the mixture of peptides in the 3 kDa permeate fractions. A fraction (F4) with potentials of ACE-inhibitory activity (IC50 = 73 μg.mL −1 ) and radical scavenging activity (IC50 = 6.8 μg.mL −1 ) was selected for further purification and fractionation. The fraction F4C obtained from a second step purification of F4 showed strong ACE-inhibitory activity (IC 50 = 36 μg.mL −1 ) as well as radical scavenging activity (IC 50 = 3.3 μg.mL −1 ). The results of this study suggest that whole camel casein can be considered as a promising source for the production of peptides with potential of ACE-inhibitory and antioxidant activities.