Improvement of leaching process of Geniposide with ultrasound

The effect of ultrasound on the leaching process, in which Geniposide is leached from the Gardenia fruit by deionized water at 20 degrees C, was investigated. The phase equilibrium and the dynamics were measured at static, stirring, and ultrasonically assisted conditions, respectively. The experimental results show that the extraction yield of Geniposide with ultrasound at 0.1533 W cm(-2), is increased by 16.5%, in comparison with that without ultrasound when the ratio of the solvent volume to the fruit weight is 40 ml/g. A model for mass transfer, based on the intraparticle diffusion and the external mass transfer, was developed. And the dynamic curves calculated by the model are in a good agreement with the experimental data. The external mass transfer coefficient k(f)/R and intraparticle diffusion coefficient D-e/R-2 were obtained by fitting of the experiment data. The external mass transfer coefficient with ultrasound at 0. 1533 W cm(-2) is 1.63 times higher than that in static process, and the intraparticle diffusion coefficient with ultrasound at 0. 1533 W cm(-2) is 3.25 times higher than that in static process. (c) 2005 Elsevier B.V. All rights reserved.