@conference{
author = "Kuzmanović Nedeljković, Snežana and Ćujić Nikolić, Nada and Bigović, Dubravka and Petrović, Predrag and Pljevljakušić, Dejan and Šavikin, Katarina and Filipić, Brankica",
year = "2022",
abstract = "Among plant natural products, Oregano and Thyme essential oils (EOs) are well-known for
their antimicrobial and antioxidant activity. The biological activities of EOs may be reduced
due to oxidation and volatilization. Stability and preservation of EOs can be assured with the
microencapsulation method based on complex coacervation technology. Cyclodextrins are
suitable as carriers for volatile substances insoluble in water, and hydroxypropyl-β cyclodextrin (HPCD) leads the group considering the aqueous solubility and safe toxicity
profile. The aim of this study was to find conditions for preparing Oregano and Thyme EOs
microencapsulates with the best technological properties.Oregano and Thyme EOs were
encapsulated by the freeze drying (lyophilization) method. Nine different combinations were
prepared, where HPCD content (10, 15 and 20%) and EO:HPCD mass ratio (1:1, 1:5 and
1:10) were varied. After stirring (200 rpm) for 24 h at a room temperature, suspensions were
filtered through 0.45 mm PTFE filters. Samples were evaporated under vacuum and frozen (-
80 °C for 1 h), then main drying was carried out (-60 °C, pressure of 0.011 mbar for 40 h),
and final drying (-65 °C, pressure of 0.054 mbar for 1 h). To ensure the particle purity,
lyophilizates were washed with acetonitrile and dried at 25 °C. The content of each EO was
determined spectrophotometrically, encapsulation efficiency (EE%) and yield were
calculated. Duncan’s post hoc test was used to evaluate the differences between samples.
The best conditions for both EOs were obtained with 15% HPCD and EO:HPCD mass ratio
of 1:10. Yields of EOs for chosen Oregano and Thyme EOs complexes were 86.81 ± 2.20%
and 89.83 ± 2.80%, respectively, with the following EE% of 49.08 ± 1.80% and 49.29 ±
0.18%. Microencapsulation is a promising method for improving the EOs stability profile,
and these results could be very useful in the pharmaceutical and food industry for the
implementation of new products.",
publisher = "Belgrade : Institute of Technical Sciences of SASA",
journal = "Twentieth Young Researchers Conference – Materials Science and Engineering, November 30 - December 2, 2022, Belgrade, Serbia - Programme and the Book of Abstracts",
title = "Microencapsulation of Oregano and Thyme essential oils with hydroxypropyl-β cyclodextrin",
pages = "14-14",
url = "https://hdl.handle.net/21.15107/rcub_farfar_5120"
}
