Turmeric products: Evaluation of curcumin and trace elements

Abstract

Turmeric (Curcuma longa L.) is valued for its coloring properties, flavor enhancement, functionality, as well as antioxidant and anti-inflammatory effects, which help prevent various diseases. This study aimed to evaluate the levels of curcumin and trace elements (Cr, Co, Ni, As, Mo, Cd, Sb, Ba, Hg, and Pb) in 30 samples of turmeric capsules. The quantification of curcumin was performed by spectrophotometry, with results ranging from 0.03 g/100 g to 37.6 g/100 g. The concentration of trace elements was determined by ICP-MS after acid digestion of the samples. Except for the elements Sb and Hg, which showed levels below the quantification limits (0.002 and 0.008 mg/kg, respectively), the results were: Cr (<0.008–0.083 mg/kg), Co (<0.003–0.78 mg/kg), Ni(<0.008–1.61 mg/kg), As (<0.003–0.083 mg/kg), Mo (<0.008–1.21 mg/kg), Cd (<0.002–0.076 mg/kg), Ba (<0.008–23.48 mg/kg), and Pb (<0.008–0.619 mg/kg). The interaction between curcumin and the trace elements was complex, with no direct relationship found between them. The estimated daily intake (EDI) of curcumin varied from 0.004 to 2.684 mg/kg of body weight, with 13 samples below 10 % of the acceptable daily intake (ADI), 12 samples between 10 % and 50 % of the ADI, and three samples above 50 %. For trace elements, Co showed the highest contribution, corresponding to 2.72 % of the health-based guidance value established by EFSA. A careful approach in marketing turmeric-based products is fundamental to ensure their quality, efficacy, and safety for consumers.