Functional Properties of Acylated Pea Protein Isolates

Pea protein isolates were acylated with succinic and acetic anhydride at 1.0, 3.0, and 5.0 mmol anhydride/g protein. The chemically modified isolates showed increased emulsifying capacity, emulsion stability, foam capacity and stability, and water adsorption compared to untreated pea protein isolate. In general, the greater the extent of acylation, the greater the improvement in emulsification properties compared to the untreated protein isolate; however, improvement at greater than 3.0 mmol anhydride/g protein was slight. Acetylation at 3 mmol/g increased foam capacity to the greatest extent. Water adsorption was enhanced to the greatest extent in protein isolates acetylated at 5 mmol/g. Acylation lowered the isoelectric point of protein isolates compared to untreated isolate. In vitro enzyme hydrolysis of the protein isolates, as determined by a multienzyme system of trypsin, chymotrypsin and peptidase, was not impaired by acylation.