pH-responsive liposomes for controlled release of Alpinia galanga essential oil: Investigating characteristics, stability, control release behavior, and functionality

The development of intelligent packaging materials has received more attention. This study designed nanoliposomes encapsulating Alpinia galanga essential oil with gamma-polyglutamic acid as a pH trigger switch and evaluated its characteristics, storage stability, controlled release behavior, and functional properties. The characteristic peaks in the ultraviolet and infrared spectrums, and the morphological observation by transmission electron microscopy indicated that the essential oils were successfully encapsulated with pH-responsive liposomes (Lip-PHEO). Also, the Lip-PHEO exhibited uniform particle size (246.50 nm), stable PDI value (0.24) and zeta-potential (33.51 mV), as well as good storage stability at 4 degrees C. Compared to the control, Lip-PHEO exhibited intelligent controlled release behavior, i.e., it can promote essential oil component release in response to pH changes, resulting in enhanced antioxidant scavenging levels (ABTS+ and DPPH free radicals) and antibacterial performance (Escherichia coli and Staphylococcus aureus). The findings provide insights for exploiting intelligent response packaging materials and expanding the application range of essential oil-based materials.