In vitro antioxidant and mineral‐chelating properties of natural and autocleaved ovotransferrin

BACKGROUND Egg white proteins can be excellent substrates for the development of functional foods and nutraceuticals. In this study, several in vitro antioxidant methods, namely the β ‐carotene linoleate model system, the ferric thiocyanate method, the 2‐thiobarbituric acid‐reactive substances ( TBARS ) method and copper/calcium ion chelation, were used to determine the antioxidant capacity of natural and autocleaved ovotransferrin. RESULTS Autocleaved ovotransferrin was prepared by reducing natural ovotransferrin with tris(2‐carboxyethyl)phosphine ( TCEP ) for 6 h at 37 °C. Autocleaved ovotransferrin suppressed the discoloration of β ‐carotene effectively and prevented the oxidation of linoleic acid during 5 days of storage at 4 °C. However, the concentration of autocleaved ovotransferrin had no influence on its antioxidant effect. Similarly, the highest TBARS values were obtained from autocleaved ovotransferrin (>90%) and the lowest value in natural ovotransferrin (24%) during incubation at 37 °C for 48 h. The hydrolysates obtained from autocleaved ovotranferrin showed better copper/calcium‐solublilizing activity than those from natural ovotransferrin. CONCLUSION The results indicated that autocleaved ovotransferrin has the potential to be used as a natural antioxidant in foods. © 2014 Society of Chemical Industry