Planta Med 2008; 74 - PC138
DOI: 10.1055/s-0028-1084656

Encapsulation of complex extracts in β-cyclodextrin: an application to propolis ethanolic extract

VT Karathanos 1, N Kalogeropoulos 1, S Konteles 2, E Troulidou 1, I Mourtzinos 1
  • 1Department of Nutrition-Dietetics, Harokopio University, El. Venizelou 70, Kallithea, 176 71, Athens, Greece
  • 2Department of Food Technology, Technological Educational Institute of Athens, 12 Ag. Spyridonos St., Egaleo, 122 10, Athens, Greece

The inclusion complex formation of a propolis ethanolic extract (PE) with β-cyclodextrin (β-CD) was applied, aiming to increase the solubility of PE constituents in water. PE extract was from North Peloponnesos, Greece, and it was found to be rich in terpenic acids and polyphenols as determined by GC/MS. The content was found to be 617mg/g and 220mg/g, respectively. Individual polyphenols and terpenic acids were determined as trimethylsilyl ether derivatives by GC/MS, operating either in selective ion monitoring (SIM) mode for polyphenols or in scan mode for terpenic acids. Quantification was performed by internal standard quantification based on a series of 9 standard mixtures of the polyphenolic and terpenic compounds, using 3-(4-hydroxyphenyl)-1-propanol as internal standard.

The preparation of inclusion complexes involved sonication of the PE suspension in aqueous solution of β-CD, followed by filtration. In order to test the potential use of β-CD cavity for the incorporation of specific components of PE the encapsulation was applied on some of the major PE components, as determined by GC-MS analysis, namely the polyphenols chrysine, caffeic acid, naringenin and kaempherol, which comprised the 56% of the polyphenols determined, and abietic acid, which comprised the 89% of total terpenic acids. All selected PE constituents formed inclusion complexes with β-CD, as it was confirmed by Differential Scanning Calorimetry (DSC).

The aqueous solubility of PE in the presence of β-CD was studied by an indirect method, which involved the construction of solubility diagrams by determining the fraction of polyphenols, which was dissolved in water in the presence of β-CD. Polyphenolic constituents were assayed with the Folin Ciocaltau reagent and the results revealed that the encapsulation in β-CD caused an increment of their solubility. It is concluded that the inclusion complexes could be incorporated in aqueous media and water-rich foods.