The comparative assessment of ACE-inhibitory and antioxidant activities of peptide fractions obtained from fermented camel and bovine milk by Lactobacillus rhamnosus PTCC 1637

The aim of this study was to compare angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities of peptide fractions obtained from fermented bovine and camel milk by Lactobacillus rhamnosus PTCC 1637 during 21 days of cold storage. The proteolytic activity was determined using the o-phthaldialdehyde method, antihypertensive effect was performed based on inhibition of ACE activity, and antioxidant activity was measured using the 2,2'-azino-bis-(3-ethyl-benzthiazoline-6-sulfonic acid) scavenging assay. In most cases, higher ACE-inhibitory and antioxidant activity was observed from cultured camel milk than bovine milk. This may be explained by structural differences and the presence of higher proline content in the primary structure of camel milk caseins compared with bovine milk. In both milk types, increased proteolytic activity during storage resulted in increased antioxidant activity. The results suggest the potential use of fermented camel milk with Lb. rhamnosus PTCC 1637 for production of dairy product with ACE-inhibitory and antioxidant properties.