Effect of heat treatment on foaming properties of ostrich (Struthio camelus) egg white proteins

ABSTRACT

The effect of heat-treatment on foaming properties of ostrich albumen was investigated. At pH 7.5, coagulation of ovotransferrin (OT) resulted in minimum foaming capacity (FC) and maximum foam density (FD). While both exposure of sulfhydryl groups of ovalbumin (OV) and OT-OV interactions improved FC at lower pH, neither of them had beneficial effect on FC at pH 9. At pH 9, FC and FD were mildly affected by heat-treatment because of less aggregation of OT, then FC decreased due to covalent aggregates composed of ovomucin and OV, but at higher temperatures, higher level of OV unfolding resulted in enhanced FC.

KEYWORDS:

• Ostrich egg white protein (OEWP)
• Heat treatment
• Foaming capacity (FC)
• Sulfhydryl groups (SH)
• Foam density (FD)

Acknowledgments

The authors are grateful to K. Khosraviani (Expert of Genetic and Biotechnology of Central Laboratory of College of Agriculture and Natural Resources, University of Tehran) for his assistance to performing gel electrophoresis.

Funding

This work has been funded by a grant provided by “The Research Council of the University of Tehran”.

Additional information

Funding

This work has been funded by a grant provided by “The Research Council of the University of Tehran”.