Turmeric, a leading adaptogen in the supplements world, has an ancient history of use for medicinal and health purposes, and in recent years, has been topping sales charts in natural food stores and retail outlets across the U.S, according to HerbalGram, the American Botanical Council’s peer reviewed journal.
 
However, reports have been made that the ingredient is often adulerated with other species in the Curcuma family, or with an undeclared mixture of starches and dyes. More recently, there has been an increasing prevalence in reports of synthetic curcuminoids, turmeric extracts, and more adulterating turmeric products.
 
A new laboratory guidance document (LGD), written by John H. Cardellina II, PhD, has been published by the American Botanical Council. It provides an evaluation of the usefulness of published analytical methods to detect the adulteration of turmeric root, raw material, extracts, and finished turmeric products, and summarizes the main advantages and disadvantages of each lab testing method in a quality control laboratory.
 
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 natural products/herbal supplement industries.
 
ABC’s chief science officer and director of the Botanical Adulterants Prevention Program (BAPP) Stefan Gafner, PhD, said that adulteration prevention for turmeric must be very thorough.
 
“Because adulteration of turmeric comes in various shapes and forms, a number of orthogonal methods are needed to ensure that the turmeric ingredient is authentic. Chromatographic methods may be useful for the detection of other Curcuma species or certain pigments, but they may miss the undeclared admixture of starches or the presence of lead chromate, which is sometimes added to impart a stronger yellow color. The possible addition of synthetic curcuminoids presents yet another analytical challenge. As such, we hope that the turmeric LGD will provide a useful guide for industry quality control analysts tasked to select the most appropriate assays for turmeric authentication.”
 
Mark Blumenthal, founder and director of both ABC and the BAPP program, said “Once again, BAPP has identified a common spice that has a growing public demand for its medicinal properties, and which unscrupulous sellers in the international herb market have adulterated with low-cost adulterants and fraudulent materials. BAPP’s newest LGD on turmeric will be a much-needed beneficial resource for hundreds of industry, university, third-party, and government analytical laboratories around the world.”
“Synthetic organic and inorganic colorants used to improve the color of poor grade or fraudulent raw material present serious health and safety concerns, while substituting or admixing with other species of Curcuma deprives consumers of the beneficial compounds provided by C. longa,” Cardellina said.
 
Safety issues can also occur from the addition of synthetic curcuminoids due to the reagents and side products used in synthesis, he added.
 
The turmeric LGD is the tenth document of its kind published by the Botanical Adulterants Prevention Program, and, like all other BAPP publications, it is freely accessible to all members of the public on the program’s website.