Hydrotropic Extraction of Curcuminoids from Turmeric

A novel hydrotropy-based extraction method for selective extraction of curcuminoids from Curcuma longa (turmeric) was investigated. The degree of extraction was dependent upon the effect of a hydrotrope on the cellular structure and hydrotrope–curcuminoids interactions. Hydrotropes directly affect the cell structure, making curcuminoids more accessible either by dissolution of the cell membrane/wall constituents or by disorganizing cell wall. Sodium cumene sulfonate (Na-CuS) was found to be an efficient hydrotrope for the extraction of curcuminoids. A significantly strong interaction with sodium n-butyl benzene sulfonate (Na-NBBS) of curcuminoids was undesirable in the recovery of curcuminoids from the extract phase, although Na-NBBS was extremely efficient in extracting curcuminoids. The two-step process, hydrotropic solubilization followed by dilution using water with or without pH adjustment, gave good yields of curcuminoids with high purity.