Microencapsulation of curcumin in cells of Saccharomyces cerevisiae

Curcumin was successfully encapsulated in yeast cells of Saccharomyces cerevisiae as confirmed by fluorescence microscopy, Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR). Emphasis was given on the encapsulation parameters including temperature, plasmolysis of yeast cells, presence of ethanol and mass ratio curcumin:cells that affected the amount of curcumin finally encapsulated, as expressed by the %Encapsulation Yield (%EY) and %Encapsulation Efficiency (%EE). Encapsulation was favoured at temperatures above 35 degrees C and preparation of microcapsules in water instead of 50% v/v ethanol increased the %EY and %EE values by at least 2-fold. Although plasmolysis of yeast cells modified membrane's fluidity and cell wall's composition, the microcapsules prepared with plasmolysed cells did not differ in their curcumin content when compared to those prepared with non-plasmolysed cells. Proper combination of the abovementioned parameters resulted in microcapsules that contained up to 35.8 +/- 0.86% w/w curcumin. In all microcapsules prepared curcumin was integrated in the plasma membrane bilayer but also interacted with constituents of the cell wall network. (C) 2010 Elsevier Ltd. All rights reserved.