Abstract
SUMMARYResearch backgroundMilk protein hydrolysates have received particular attention due to their health-promoting effects. Dromedary milk differs from the milk of other dairy animals in the composition and structure of its protein components, which give it unique properties. The bioactivity and functionality of whole dromedary milk proteins and their enzymatic hydrolysates have not received much attention, hence this study aims to investigate the effect of enzymatic hydrolysis of dromedary milk proteins on their antioxidant activities and functional properties.Experimental approachDromedary milk proteins were treated using four proteolytic enzymes (pepsin, trypsin, α-chymotrypsin and papain) and two mixtures of enzymes (pancreatin and pronase). The degree of hydrolysis was measured to verify the hydrolysis of the proteins. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography served to determine the molecular mass distribution of the hydrolysates while reversed phase-high performance liquid chromatography (RP-HPLC) was conducted to explore their hydrophobicity. The antioxidant activities were evaluated using various in vitro tests, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging capacities, iron(III) reducing ability and chelating activity. Besides, functional properties such as solubility, foaming and emulsification were assessed.Results and conclusionsDromedary milk protein hydrolysates exhibited different degrees of hydrolysis ranging from 17.69 to 41.86%. Apart from that, the hydrolysates showed different electrophoretic patterns, molecular mass distribution and RP-HPLC profiles demonstrating the heterogeneity of the resulting peptides in terms of molecular mass and polarity. The hydrolysates displayed significantly higher antioxidant capacities than the undigested proteins at all the tested concentrations. Iron(II) chelating activity was the most improved assay after proteolysis and the hydrolysate generated with pancreatin had the highest chelating power. Dromedary milk protein hydrolysates possessed good solubility (>89%). Further, foaming and emulsifying properties of dromedary milk proteins were enhanced after their proteolysis. These interfacial properties were influenced by the enzymes employed during proteolysis.Novelty and scientific contributionEnzymatic hydrolysis of dromedary milk proteins is an effective tool to obtain protein hydrolysates with great antioxidant and functional properties. These results suggest that dromedary milk protein hydrolysates could be used as a natural source of antioxidant peptides to formulate functional foods and nutraceuticals.
Highlights
Endogenous generation of reactive oxygen species (ROS) is unavoidable in aerobic organisms because it is a consequence of normal metabolic processes
Enzymatic hydrolysis of dromedary milk proteins is an effective tool to obtain protein hydrolysates with great antioxidant and functional properties. These results suggest that dromedary milk protein hydrolysates could be used as a natural source of antioxidant peptides to formulate functional foods and nutraceuticals
Various proteases were employed to hydrolyse dromedary milk proteins in order to assess the functionality of the generated protein hydrolysates
Summary
Endogenous generation of reactive oxygen species (ROS) is unavoidable in aerobic organisms because it is a consequence of normal metabolic processes. The production of ROS is activated by exogenous sources such as exposure to air pollutants, radiation, pesticides and ozone. The excess of ROS leads to oxidative stress, which is related to the occurrence of numerous ailments like cancer, cardiovascular, inflammatory diseases and neurodegenerative disorders [2]. Organisms possess antioxidant defence systems against oxidative stress like antioxidant thiols and enzymes. Under pathological or extreme environmental conditions, endogenous antioxidants are not sufficient to remove ROS and external sources of antioxidants are required [3]. Various synthetic antioxidants have been extensively utilized in pharmaceutical and food industries to prevent oxidative damage. There is an increasing interest in finding new and safe antioxidants from natural sources
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
