Physicochemical and release characterisation of garlic oil-β-cyclodextrin inclusion complexes

Garlic oil (GO), rich in organosulphur compounds, has a variety of antimicrobial and antioxidant activities, however, its volatility and low physicochemical stability limit its application as food functional ingredients. The aim of this study was to investigate the physicochemical and release characterisation of inclusion complexes of GO in beta-cyclodextrin (beta-CD). The formation of GO/beta-CD inclusion complex was demonstrated by different analytical techniques including Fourier transform-infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry. The stoichiometry of the complex was 1:1. The calculated apparent stability constant of GO/beta-CD complex was 1141 M-1, and the water solubility of GO was significantly improved by the phase solubility study. Furthermore, the release of GO from the inclusion complex was determined at a temperature range from 25 to 50 degrees C and in an acidic dissolution medium (pH 1.5), respectively. The release rate of GO from the inclusion complex was controlled. (C) 2011 Elsevier Ltd. All rights reserved.