Comparison of thermo-rheological, microstructural and antimicrobial properties of β- and γ-cyclodextrin inclusion complexes of cinnamon essential oil

This study aimed to produce freeze-dried inclusion complex of cinnamon essential oil (CEO) using beta-cyclodextrin (BCD) and gamma-cyclodextrin (GCD) as wall materials in two selected weight ratios (85/15 and 80/20). Encapsulation efficiency (EE) of CEO was significantly higher when the CD/CEO ratio was maintained at 80/20. Additionally, the GCD exhibited an excellent EE (96.5%) than the BCD (71.02%). Various analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and rheological measurements demonstrated that the CEO was efficiently encapsulated in the cavity of cyclodextrins. Rheological data of CD and CEO in solution were fitted to the Herschel-Bulkley and Cross model well. The antimicrobial activity of the inclusion complexs (ICs) displayed that the CEO in GCD (80/20) had the excellent inhibitory effect against Listeria monocytogenes, and Salmonella enterica sv Typhimurium. Overall, the GCD acts as a superior wall material by forming an excellent IC with CEO with desirable properties. The obtained results demonstrated that both encapsulates would have potential for use as intermediate materials in antimicrobial food packaging.