Carbodiimide stabilizes the ultrasound-pretreated camelina protein structure with improved water resistance

Camelina protein showed poor water resistance, which restrained its industrial application, such as for adhesives or coatings. In this research, the effect of ultrasound pretreatment and carbodiimide coupling on water resistance of camelina protein isolate (CPI) was discussed. Camelina protein was extracted from defatted camelina meal by alkali solubilization and acid precipitation and treated by high intensity ultrasound. Both CPI and ultrasound-modified CPI (UCPI) were cross-linked by Ethyl-3-(3-dimethyl-aminopropyl-1-carbodiimide) (EDC). The cross-linked CPI exhibited increased molecular weight and particle size due to the amide bond formation between free amino groups and carboxyl groups. Accordingly, microstructures of the coupled protein became rigid and condensed with increased aqueous stability. The crosslink degree of UCPI was higher than CPI, leading to UCPI's better water resistance, more compact microstructures and larger particle size.