Turmeric Raw Material and Products Laboratory Guidance Document Published by Botanical Adulterants Prevention Program

While turmeric (Curcuma longa, Zingiberaceae) has a long history of use as a spice and medicinal plant, its popularity has only recently started to surge in countries outside Asia. In 2018, it ranked second and third in herbal dietary supplement sales in the US natural food store and mainstream retail outlet channels, respectively, according to HerbalGram’s annual Herb Market Report.¹

Reports of turmeric adulteration often describe substitution with other Curcuma species or the admixture of starches or dyes. More recently, the addition of undeclared curcumin, one of the naturally occurring substances in turmeric, made by chemical synthesis or mixtures of synthetic curcuminoids to turmeric extracts, has been reported. Synthetic curcuminoids can be made for about one-third of the cost of natural curcuminoids, providing a financial incentive to fraudulent suppliers for diluting or replacing turmeric extracts with synthetic materials.

The new laboratory guidance document (LGD)² marks the 10th publication in the series of LGDs. It was written by John H. Cardellina II, PhD, a highly respected expert in natural products chemistry and analysis. The LGD provides an evaluation of the usefulness of published analytical methods to detect the adulteration of turmeric root/rhizome raw materials and extracts, and finished turmeric products, and summarizes the main advantages and disadvantages of each method regarding its suitability for use in a quality control laboratory. In addition to the assessment of the analytical methods, the document details the chemical composition of turmeric root and rhizome, potential confounding species, and known adulterants. The LGD has been peer-reviewed by 29 international experts from academia, third-party contract analytical laboratories, and the herbal dietary supplement and herb and spice industries.

References

1. Smith T, Gillespie M, Eckl V, Knepper J, Reynolds CM. Herbal supplement sales in US increase 9.4% in 2018. HerbalGram 2019; 123:62-73.
2. Cardellina II JH. Turmeric raw material and products laboratory guidance document. Austin, TX: ABC-AHP-NCNPR Botanical Adulterants Prevention Program. 2020:1-13.