An antioxidant peptide derived from Ostrich (Struthio camelus) egg white protein hydrolysates

Tanzadehpanah, Hamid; Asoodeh, Ahmad; Chamani, Jamshidkhan

An antioxidant peptide derived from Ostrich (Struthio camelus) egg white protein hydrolysates

2012

Tanzadehpanah, Hamid | Asoodeh, Ahmad | Chamani, Jamshidkhan

Ostrich (Struthio camelus) egg white (OEW) proteins were hydrolyzed using various proteases (α-chymotrypsin, pepsin, trypsin and papain). Antioxidant activities of hydrolysates were evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and iron chelating activity. The hydrolysate obtained by trypsin exhibited the highest antioxidant activity. This hydrolysate was passed through an ultrafiltration membrane with a 3kDa-cut off, and the resulting filtrate was purified using reversed-phase high performance liquid chromatography (RP-HPLC). Eight peptide fractions were separated and their antioxidant activities were tested. The results showed that the F₆ fraction possessed the highest antioxidant activity in the inhibition of linoleic acid autoxidation (86.4% at 20μg/ml), scavenging activity for DPPH radical (81% at 200μg/ml) and 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical (37.6% at 90.9μg/ml). In addition, the iron chelating activity, hydroxyl radical scavenging and reducing power of the F₆ fraction were 20% at 317.5μg/ml, 28.6% at 163.9μg/ml and 0.083 at 113.6μg/ml, respectively. The peptide sequence was found to be LTEQESGVPVMK (with a molecular mass of 1317.65Da) using mass spectrometry. The results suggest that the digestion of OEW proteins by trypsin protease could be exploited to produce natural antioxidants.

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