Morphometric characterization of spray-dried microcapsules before and after α-tocopherol

Microcapsules were obtained by spray-drying of α-tocopherol (AT) - in- water emulsions subjected to single and double atomization yielding single atomized microcapsules (SAM) and double atomized microcapsules (DAM) which had different core to wall material ratios. Micrographs of whole and AT extracted of SAM and DAM obtained from Environmental Scanning Electron Microscopy (ESEM) were image analyzed and the Feret diameter, projected area, perimeter, maximum perimeter, shape factor and Fractal Dimension of contour (FDc) and texture (FDt) were determined. Whole DAM presented higher FDc and FDt than SAM, while SAM presented higher FDc values for all the microcapsules and higher DFt values for the AT to wall materials ratios 1:4 after the AT extraction. Most of the microcapsules displayed significantly different perimeter but non- significant projected areas, whereas the extracted microcapsules tended not to show significant differences between these two parameters.