CURCUMINOID ANALYSIS OF HAWAII-GROWN TURMERIC (Curcuma longa) BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND INVESTIGATION OF COLOR RELATIONSHIP WITH CURCUMINOID CONTENT FOR TOTAL CURCUMINOID ESTIMATION

An HPLC method was designed to analyze turmeric (Curcuma longa) cultivars for curcuminoid contents curcumin, demethoxycurcumin and bis-demethoxycurcumin, and the sum of these were taken as total curcuminoids (TC). Of the Hawaii-grown cultivars, ‘Joy’ contained significantly more TC than all the others, with exception to ‘BKK’, a low yielding but extremely high TC cultivar. ‘Olena’ was the only cultivar to have less TC than what is commercially acceptable. Of the Asian cultivars analyzed, Indian cultivars 18-013, 18-014, and 18-010 had the highest TC content, comparable to ‘BKK’. Further propagation and in field trials will demonstrate their yield potential. The colors of the Hawaii-grown and Asian cultivars were measures using a standardized color chart to design a color grading chart. The yellow to orange relationship with TC content was used to produce approximate colors for different levels of curcuminoid content. These results and future experiments will help guide Hawaii agriculture towards producing high quality and globally competitive turmeric rhizomes.