The effect of the pH and of the trypsin 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 vaules for EC and ES were obtained at pH 5.0 and 6.0, respectively, corresponding to the range of large 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 ranges 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.
blood; bovine globin; tryptic hydrolysis; emulsifying properties
