Hydrogel particles as a controlled release delivery system for lavender essential oil using pH triggers

Owing to the antibacterial properties of lavender essential oil (LEO), it can be used in food packaging to improve food quality and increase shelf life. LEO has also been shown to be effective for the treatment of several neurological disorders, including depression and insomnia. However, the practical applicability of LEO is limited by its high volatility. This study aimed to investigate the possibility of using hydrogel particles as carriers to encapsulate and control the release of LEO, thereby improving its storage and delivery. LEO was first loaded into oil-in-water emulsions that were then encapsulated in hydrogel particles. These hydrogel microparticles were cross-linked with different concentrations of Ca2+. The influence of Ca2+-mediated cross-linking on the properties and stability of the hydrogel microparticles was investigated. The release of LEO from the hydrogels was determined by dynamic and static headspace analyses. The results showed that the hydrogel particles not only improved LEO stability during storage but also delayed LEO release under real-time, dynamic conditions. This study suggests the potential application of hydrogels as a novel aroma delivery system for the controlled release of essential oils.