Octenyl succinic anhydride-modified starches as emulsifier agents: A comparative study emphasizing stability,...

New alternatives for emulsification are a relevant topic of pharmaceutical research due to the safety concerns of certain materials and the interest in achieving environmentally friendly products. In this sense, this work investigates the performance of five waxy corn starches modified with octenyl succinic anhydride (Hi-Cap® 100, Purity Gum® 2000, Capsul®, N-Creamer® 46, and Purity Gum® Ultra) as emulsifiers, employing caprylic/capric triglyceride as the oily phase and water as the aqueous phase. The type of modified starch influences the droplet size and rheological behavior of emulsions. The systems prepared with N-Creamer® 46 and Purity Gum® Ultra allow the most stable emulsions for 180 days at ∼20 and 40°C ± 0.1°C. The other starches evaluated do not favor the emulsions´ stability, probably due to their lower values of molecular weight, z-average radius of gyration, and dispersed molecular density. Interestingly, the study of the emulsions´ microstructure provides evidence of a three-dimensional starch network around the oil droplets, suggesting the steric effect as the primary mechanism of stabilization when these biopolymers are used. ζ-Potential measurements and the test of electrolyte-induced aggregation corroborate this. These findings contribute to the understanding of how emulsions are stabilized by hydrophobically modified starches, a subject of paramount importance for developing innovative pharmaceutical products.