Encapsulation of tea tree oil by amorphous beta-cyclodextrin powder

Food Chem. 2017 Apr 15;221:1474-1483. doi: 10.1016/j.foodchem.2016.11.003. Epub 2016 Nov 2.


An innovative method to encapsulate tea tree oil (TTO) by direct complexation with solid amorphous beta-cyclodextrin (β-CD) was investigated. A β-CD to TTO ratio of 90.5:9.5 (104.9mg TTO/g β-CD) was used in all complexation methods. The encapsulation was performed by direct mixing, and direct mixing was followed by the addition of water (13-17% moisture content, MC) or absolute ethanol (1:1, 1:2, 1:3 and 1:4 TTO:ethanol). The direct mixing method complexed the lowest amount of TTO (60.77mg TTO/g β-CD). Powder recrystallized using 17% MC included 99.63mg of TTO/g β-CD. The addition of ethanol at 1:2 and 1:3 TTO:ethanol ratios resulted in the inclusion of 94.3 and 98.45mg of TTO/g β-CD respectively, which was similar to that of TTO encapsulated in the conventional paste method (95.56mg TTO/g β-CD), suggesting an effective solid encapsulation method. The XRD and DSC results indicated that the amorphous TTO-β-CD complex was crystallized by the addition of water and ethanol.

Keywords: Amorphous β-cyclodextrin powder; Crystallization; Ethanol; Molecular encapsulation; Tea tree oil.

MeSH terms

  • Ethanol / chemistry*
  • Powders
  • Tea Tree Oil / chemistry*
  • beta-Cyclodextrins / chemistry*


  • Powders
  • beta-Cyclodextrins
  • Ethanol
  • Tea Tree Oil