The aim of this study was to produce covalently attached conjugate between canola protein isolate (CPI) and gum Arabic (GA) in aqueous solutions via the Maillard reaction at 90 °C in a model system consisting of 2% CPI and 1, 2 or 4% GA. Upon decreasing of free amino group content in the glycosylated CPI to 72%, a new band near the loading end of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a shift of CPI peak in high performance size exclusion chromatography confirmed that the covalent attachment of CPI to GA was successful. The results of secondary structure analysis suggested that grafted CPI had decreased ?-helix and ?-sheet levels and increased random coils level. The solubility of CPI at isoelectric point was improved remarkably after grafting with GA. The optimal conjugation conditions chosen from the further experiments were 1% of GA, 90 °C and reaction time 15 min. Also, the stability, rheology and morphology of oil-in-water emulsions stabilized by conjugate of these two natural biopolymers were evaluated using droplet size, emulsifying activity (EAI), emulsifying stability (ESI) and creaming indices. Conjugate-stabilized emulsion showed smaller mean droplet size and lower creaming index values which were more effective at stabilizing emulsion compared to CPI alone and mixture of two biopolymers especially if pH was near the isoelectric point of CPI or when emulsions heated from 30 to 90 °C. Moreover, our results demonstrated that EAI, ESI and viscosity of emulsion for CPI-GA conjugate were significantly more than that of CPI-GA mixture and CPI. These results suggested that Maillard reaction could be one of the most promising approaches to improve emulsifying properties of CPI for food applications. Meanwhile, the results of thermal properties, foaming and antioxidant properties of conjugate showed that these properties of CPI were improved by glycation through Maillard reaction.
