Rheological characteristics of commercial canola protein isolate-κ-carrageenan systems


The thermogelation properties of canola protein isolate (CPI) in a mixed system with κ-carrageenan (κ-CAR) were examined using dynamic rheological testing. The effects of pH, NaCl, κ-CAR and protein concentrations on the gelling ability of CPI were evaluated. Factorial and response surface optimization models were used to identify the processing conditions that would result in CPI–κ-CAR gels with maximized G′ values (≥44 000 Pa) and minimized values (0.01–0.11). It was found that canola protein–carrageenan gel formation was strongly pH-, NaCl- and κ-CAR concentration-dependent. Results indicated that the optimum conditions for CPI–κ-CAR gels was pH 6, 0.05 M NaCl, 3% κ-CAR and 15% CPI. Samples prepared at pH 6 showed high G′ (95 465 Pa) and low values. High G′ values indicate stronger intermolecular network and increased interactions between protein–protein and protein–polysaccharide molecules, while low values indicate a more elastic network. A synergistic behavior between CPI and κ-CAR was observed with superior network strength (high G′ values) for the mixed gels at temperatures above 80 °C. Further, the gels showed improved network structure (low values) during the heating and cooling phases. The canola protein–κ-carrageenan mixtures exhibited very strong and elastic networks, indicating that CPI can serve as a structuring agent in mixed food systems.


Biomedical Sciences

Document Type





canola protein isolate, gelation, κ-carrageenan, structuring agent, dynamic rheology

Publication Date


Journal Title

Food hydrocolloids 18