Pickering emulsion stabilized by composite-modified waxy corn starch particles.

Abstract

The starch-based Pickering stabilizer has attracted more research interest recently, however, its application in food system is limited due to the low digestibility of raw starch particles. In this study, waxy corn starches were modified with octenyl succinic anhydride and then treated by dry heating at 180°C for 20-60min. Pickering emulsions stabilized by the composite-modified starch particles were fabricated, the physical stability, rheology property and microstructure of the emulsions were investigated. The results showed that the composite-modified starches maintained granule structure, their gelatinization temperatures and enthalpy significantly reduced after heat treatment (p<0.05). Compared with native starch, the composite-modified starches had bigger three-phase contact angles and higher in vitro digestibility, while the relative crystallinity decreased from 32.46% to 24.87%. Pickering emulsions stabilized by composite-modified starch particles had long-term stability up to 300days. The rheology results showed that all emulsions exhibited pseudoplastic behaviors and had higher storage modulus than loss modulus. Moreover, the viscosities decreased when the starch was roasted for 40 and 60min. The composite-modified starch particles and few starch macromolecules at oil-water interface stabilized the emulsions collectively. These results provide a new strategy for designing an edible Pickering stabilizer.