Extraction of secondary metabolites from plant material: a review

This review article intends to give an overview of the developments in the extraction technology of secondary metabolites from plant material. There are three types of conventional extraction techniques. In order of increasing technological difficulty, these involve the use of solvents, steam or supercritical fluids. Each of these types of extraction methods is described in detail with respect to typical processing parameters and recent developments. Following the discussion of some technical and economic aspects of conventional and novel separation processes, a few general conclusions about the applicability of the different types of extraction techniques are drawn