Preparation of Zein Based Ginger Essential Oil-enriched Pickering Nanoemulsions Using Multi-frequency Ultrasound to Enhance Emulsion Properties and Antioxidant Activities

Zein-based ginger essential oil-enriched Pickering nanoemulsions were prepared using 20/28/40 kHz multi-frequency ultrasound treatment to enhance emulsion properties and their antioxidant activities. The study characterized the effects of different treatments on the encapsulation capacity, loading capacity, particle size, polydispersity index, and Zeta potential of the emulsions. Additionally, changes in the secondary structure of zein and the microstructure of the emulsions were evaluated to determine structural modifications. The results showed that after ultrasound treatment, the emulsions had an average particle size of 81 nm and a Zeta potential of -32.80 mV, maintaining high emulsion stability even after 25 days of storage. In addition, the emulsions prepared with multi-frequency ultrasound exhibited the optimal antioxidant performance. The DPPH radical scavenging capacity and ABTS radical scavenging capacity were measured at 65% and 37%, respectively. This study provides a reference for the development of protein-based emulsions and offers a viable alternative for the delivery of antioxidant essential oils.