Modification of Pickering emulsions using zein-tannic acid particles: enhancement of antioxidant and thermal stability properties of citral

Citral is one of the main components of everyday chemical fragrances and Its fragrance cannot be retained for long due to its active chemical properties. Currently, potentially toxic or expensive industrial surfactants are commonly used to emulsify flavors or essential oils, and most of the dispersed systems formed are thermodynamically unstable. In this study, modified corn protein was used as a solid particles and xanthan gum as a co-emulsifier to form an O/W type Pickering emulsion. Corn protein was modified with natural plant polyphenol–tannin to obtain solid particles with optimal amphiphilicity and antioxidant properties, and the particle size was approximately 170 nm. The Pickering emulsion was dispersed using a high-speed homogenizer. The percentage of encapsulated citral in the system was 20%. The particle size, polydispersity index, and citral encapsulation rate were 32.48 μm, 0.323, and 91.26%, respectively. The Pickering emulsion significantly improved the stability of the encapsulated citral, and the retention of citral in harsh environments (both high temperature and aerobic) was significantly increased. After one month of storage, the citral retention in the Pickering emulsion was 86.95% under aerobic conditions.