Evaluation of Functional Properties of a Blood Protein

Abstract

Aiming to evaluate the functional properties of a blood protein, the emulsifying ones were chosen to be studied in this work. Thus, the effect of the pH and of the tryptic hydrolysis on the emulsifying properties of bovine globin, extracted by the acidified acetone method, was studied. The emulsifying capacity (EC), the emulsifying activity index (EAI) and the emulsion stability (ES) were determined at pH varying from 3.0 to 8.0 and employing hydrolysis times from 5 to 60 min. The highest values for EC and ES were obtained at pH 5.0 and 6.0, respectively, corresponding to the range of high protein solubility. On the other hand, the EAI was higher at pH 3.0 and also at pH 7.0 and 8.0, where the protein is insoluble. The tryptic hydrolysis produced an increase in EC, in all pH range studied, while for the EAI the same effect was observed only in pH 4.0 and 5.0, and for ES at pH 7.0 after 60 min of hydrolysis.