Determination of curcuminoid colouring principles in commercial foods by HPLC

The present study deals with determination of curcuminoids, which are potential sources of a natural food colourant, present in commercially available food items in Korean markets. Three principles, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3), were isolated from Curcuma longa roots. Moreover, their contents were investigated in 54 items of 16 food types by HPLC-DAD at 420 nm. The recovery rates showed remarkable differences, and ham of solid state exhibited the highest rate (98.9%), while beverage of liquid state was the lowest (0.34%). Among food items, curcumin (1) detected the predominant content and curry showed the highest curcuminoid in the range of 37.24-617.98 mu g/g. Interestingly, curry powder was the highest content, followed by compressed curry, and retorted curry. The remaining food items, only mustard, candy, and pickle exhibited curcuminoids. This study provides that analysis of curcuminoids may be a potential tool for the quality control of manufactured foods. (C) 2010 Elsevier Ltd. All rights reserved.