Cyclodextrin (CD) has a crown-like structure which is cyclic (α-1, 4) linked oligosaccharide. It produces from starch by enzymatic conversion. CD is an unstable compound. Therefore, it usually combined with other chemicals to form a stable aqueous compound. Typical CDs are constituted by 6-8 glucopyranoside units, it represents with the larger and the smaller openings exposing to the
solvent secondary and primary hydroxyl groups respectively. Because of this arrangement, the interior of the CD is not hydrophobic, but considerably less hydrophilic than the aqueous environment and thus able to host other hydrophobic molecules. In contrast, the exterior is
sufficiently hydrophilic to impart CDs (or their complexes) water solubility. β-cyclodextrin (β-CD) has been on the GRAS (Generally Recognize as Safe) list since 1998, as a flavour carrier and protector, at a level 2% in numerous food products. Based on the previous researches [12][13], they commonly used β-CD and its derivatives to form a complex with other compounds due to its ability to produce a complex with comparable quality as aroma, colour and appearance.
Usually, β-CD been used as an encapsulation agent. Several researchers had encapsulated complex materials like oleoresin, essential oil (Salvia sclarea L. essential oil, Lippia sidoides oil and lemon oil) and fatty acid compounds (lineoleic acid and cholesterol) with CD [3][12] [13].