Sustained release and insect repellent activity of cinnamon essential oil active label based on three-step encapsulating

To address the issue of rapid release of cinnamon essential oil (CEO) in active packaging applications, this study aimed to develop a sustained-release active label. CEO was encapsulated step by step to form cinnamon essential oil microemulsions (CEO-MEs), cinnamon essential oil microcapsules (CEO-MPs), and cinnamon essential oil sustained-release active labels (CEO-SRAL). Microstructure, thermal property and release property of the intermediate and final products obtained through the three-step embedding method were characterized, along with their anthelmintic activity. Results showed that the average particle size of CEO-MEs was 29.02 nm. The BJH pore size of porous CS/β-CD complex was 44.36 nm. CEO was encapsulated step by step and evenly distributed. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that multiple encapsulations of CEO didn't result in any adverse chemical reactions. The active label began to degrade at 290–400 °C with great thermal stability. The cumulative release days of CEO-SRAL were 20 days. The cumulative release concentration of CEO in CEO-SRAL was 31.99 mg/mL. Furthermore, the fumigation and repellent rates of three-step packaging products containing CEO to S.oryzae were more than 90%. These results indicated that the three-step encapsulation method could improve the performance of CEO to enhance the use of essential oil.