Preparation and Characterization of Pickering Emulsion Stabilized by OSA Starch/Chitosan Complexes

In this study, octenyl succinic anhydride-modified starch (OSA starch) with different degrees of substitution (DS) was used as raw materials, which was combined with chitosan (CS) to make a complex. The effects of DS on the change of functional groups and wettability of the complex were studied. Pickering emulsions stabilized by OSA starch/chitosan complexes with different volume fractions of oil phase (20%, 50%, 80%) were prepared, and the effects of DS and volume fractions of oil phase on the stability of the emulsion were investigated. The results showed that the hydrophobicity increased significantly with the DS of OSA starch increasing. When the addition amount of octenyl succinic anhydride (OSA) was 2%, the contact angle of the complex was closest to 90°, which showed the suitable wettability. With the DS or the volume fraction of oil phase increasing, the diameters of emulsion particles increased, the droplet distribution became more even and dense, and the emulsion state got closely to solid. Moreover, the volume fraction of oil phase had more prominent effects on the emulsion. When DS was 0.00895 and the volume fraction of emulsion oil phase was 80%, the emulsion average particle size was 27.4±1.4 μm and had gel network structures. After storaging under −4 ℃ for 30 days, the emulsion had no creaming phenomenon and exhibited good ionic and temperature stability. This study further explored the parameter settings of Pickering emulsion stabilized by OSA starch-polysaccharide complexes, which was expected to promote the development and application of this emulsion.