Utilization of octenyl succinic anhydride-modified pea and corn starches for stabilizing oil-in-water emulsions

In this study, pea starch (41.5% amylose), normal corn starch (32.9% amylose), and waxy corn starch (1.7% amylose) were modified using three concentrations of octenyl succinic anhydride (OSA). The degrees of substitution, thermal properties, and pasting properties of the derived OS-starches were determined. Canola oil-inwater (O/W) emulsions were prepared using a high-pressure homogenizer with the OS-starches to evaluate their emulsifying properties, with gum Arabic (GA) being included as the industry standard for comparison. Dropletsize distributions, zeta potentials, accelerated stability, and storage stability of the resultant emulsions were determined and compared. Emulsion stability under various environmental conditions was also investigated, including pH 2?7, 0?1.0 M sodium chloride in aqueous medium, and incubation at 90 ?C for 30 min. Overall, the ability of the emulsifiers in stabilizing O/W emulsions followed an ascending order of OS-PS < GA ? OS-NCS < OS-WCS. Emulsifying properties of the OS-starches and stability of the resultant emulsions were generally enhanced with a higher degree of substitution. The interrelationships among the molecular structures (e.g., amylose content and degree of substitution), functional properties (e.g., retrogradation rate), and emulsifying ability of the OS-starches were also elucidated. The new findings from the study can be used to further tailor the structures of OS-PS to improve the emulsifying properties for potential industrial uses.