Abstract:Application of starch-based Pickering emulsion was widely investigated in food, medicine and cosmetics. In this study, ultrasonic-assisted octenyl succinic acidification and ball milling on millet starch were used to improve the emulsifying ability and stability. The corresponding mechanism was elucidated by measuring the degrees of substitution and hydrolysis, characteristic functional groups, crystal structure, micromorphology, particle size and emulsifying index. The results showed that ultrasonic treatment improved the reaction efficiency and substitution degree. The OSA groups were mainly grafted in the amorphous region of millet starch, and slightly entered into the crystalline region. Ball milling destroyed the particle morphology and crystal structure of OSA millet starch. The ability to form Pickering emulsion of OSA millet starch and the emulsion stability were significantly enhanced with the increase of ball milling duration and the amount of millet starch added. Ultrasound-assisted octenyl succinic acidification combined with ball milling is an effective technology to prepare starch-based Pickering emulsions with high emulsion stability, which is conducive to develop and utilize starch resources in the field of Pickering emulsion.
