Emulsifying characteristics of commercial canola protein-hydrocolloid systems

Emulsifying properties of commercial canola protein isolate (CPI)-hydrocolloid-stabilized emulsions were evaluated under varied conditions (CPI, salt and hydrocolloid concentrations; pH, denaturants). Emulsifying activity index (EAI) and emulsion stability (ES) were determined by turbidimetric testing. The results showed that under complexing conditions (at pH 6), the addition of 1% (w/v) κ-carrageenan (κ-CAR) increased the EAI of CPI-stabilized emulsions from 162 to 201 m2/g and ES from 68% to 95%. Under conditions promoting incompatibility (at pH 10), the use of 1% (w/v) guar gum increased the EAI of CPI-stabilized emulsions from 68 to 177 m2/g and ES from 66% to 100%. The lower EAI and ES values observed in CPI-hydrocolloid-stabilized emulsions treated with sodium salts and denaturants support the involvement of hydrophobic interactions, hydrogen bonds and disulfide linkages in the emulsification of these systems. Interfacial properties of CPI-hydrocolloid mixtures were improved by electrostatic complexing and incompatibility, making these systems suitable for stabilizing food emulsions.