Quality assessment of Curcuma dietary supplements: Complementary data from LC-MS and 1H NMR

Due to the numerous potential health benefits of Curcuma, turmeric dietary supplements (DS) are among the top selling products. To assess the quality of these formulations, thirty Curcuma DS along with five standard Curcuma rhizomes were analyzed with UHPLC-MS and 1H NMR. The chemometric treatment of the UHPLC-MS spectra showed a significant variability of their chemical composition that was confirmed by 1H NMR which allowed the absolute quantification of the Curcuma major bioactive components, i.e. curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin), and turmerones (aryl-, α- and β-) as well as piperine, a commonly associated curcumin bioavailability enhancer: respectively 3.5–556, 0–8.6, 0.18–8.1 mg/capsule or tablet. The comparison of the actual and claimed quantities of curcuminoids and piperine showed that 58% of the DS contained the expected amounts of actives. [Display omitted] •UHPLC-HRMS and 1H NMR analyses of Curcuma dietary supplements for quality control.•Curcumin, DMC, BDMC, aryl-, α-, β- turmerones and piperine were quantified by 1H NMR.•74% of formulations with curcuminoids content label contained declared amount.•54% of formulations with piperine content label contained declared amount.