Influence of enzymatic hydrolysis, pH and storage temperature on the emulsifying properties of canola protein isolate and hydrolysates

The aim of this work was to enhance emulsification properties of canola proteins through enzymatic proteolysis and pH variaton. Canola protein isolate (CPI) and hydrolysates (CPHs) were used to form emulsions at pH 4.0, 7.0 and 9.0 followed by storage at 4 or 25 degrees C for 7days. Controlled enzymatic hydrolysis led to increased peptide bond cleavage with time (0.23g/100g in CPI to 7.18g/100g after 24-h Alcalase hydrolysis). Generally, oil droplet sizes were smaller for emulsions made at pH 9.0, which suggest better quality than those made at pH 4.0 and 7.0. Trypsin hydrolysate emulsions were the most physically stable at pH 7.0 and 9.0; in contrast, the pepsin hydrolysate emulsions were unstable at all conditions. The results suggest that selective enzymatic hydrolysis could play an important role in enhancing successful incorporation of canola proteins and peptides into food systems as protein emulsifiers.