Characterization of commercially available turmeric for use in pharmaceutical products and food supplements

We addressed some physicochemical and biological differences in commercial turmeric, acquired from both handling pharmacies and stores selling natural products for quality assessment. For this, it was determined the melting point, antioxidant activity by 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH), antimicrobial activity via the agar disk-diffusion assay, metallic contaminants by X-ray fluorescence with energy dispersion (EDXRF), spectral behaviors by Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) and determination of curcumin concentration by UV-Vis. The results obtained of the several commercial turmeric samples were not homogeneous, showing in fact significant differences regarding melting points, UV-Vis spectral scan profiles, and FTIR spectra, presenting toxic metals and quite low curcumin contents. This sheds light on the urge to implement adequate quality control in this type of raw material for human safe use of curcumin. Particularly, contamination with heavy metals, such as mercury, is a serious health problem, due to its high toxicity and accumulative power in the body. (author)