Criteria to Detect Adulteration of Asian Ginseng Published by Network Nutrition
As part of a routine exercise, the research team from Network Nutrition/IMCD, a supplier of botanical ingredients based in Bella Vista, NSW, Australia, collected 12 commercial samples of Asian ginseng (Panax ginseng, Araliaceae) extract to determine authenticity. Samples were from different European manufacturers and originated in Europe (n=6), China (n=5), or Korea (n=1). Most samples were labeled to contain root extracts, although one sample was labeled to be a leaf and stem extract, and another extract was made from ginseng berries. Eight ginsenosides were analyzed in each sample using the high-performance liquid chromatography (HPLC) conditions outlined in the United States Pharmacopeia.
Adulteration with American ginseng (P. quinquefolius) extract was suspected in samples that did not contain ginsenoside Rf, and in which the peak area ratio for ginsenosides Rb2:Rb1 was below 0.4 and the ginsenoside Rb1:Rg1 was above 10. High ginsenoside Rg1:Rf (above 19.5) and ginsenoside Re:Rf (above 42.5 in the paper) ratios in the samples indicated adulteration with Asian ginseng leaf extract material.
Of the 10 root samples, two were found to be adulterated with American ginseng root extract, and two contained undeclared leaf and stem extract material. An additional sample was apparently adulterated, but the identity of the adulterant could not be determined.
Comment: Given the fact that Asian ginseng is a relatively high-cost raw material, there is an incentive for economically motivated adulteration. Substitutions with roots from other Panax species, in particular extracts of P. quinquefolius, and with Asian ginseng leaf extracts, are the most commonly found types of adulteration.1,2 HPLC-UV profiling with visual evaluation, or with subsequent statistical evaluation is one way to detect such adulteration.3,4 For those laboratories that do not have the expertise and necessary software to do the chemometrics, the use of ratios, as presented in the paper by Network Nutrition, will be useful. However, data on ginsenoside Rg1:Rf and ginsenoside Re:Rf ratios from a larger number of Panax ginseng root, leaf, stem, and berry extracts will need to be analyzed in order to put forward more definite ratio limits as a means to detect admixture of other plant parts to the root extracts.
References Foster S. Toward an understanding of ginseng adulteration: the tangled web of names, history, trade and perception. HerbalGram. 2016;111:36-57. Kilham C, Bily A. Adulteration of herbs: a matter of global importance. Presented at: Natural Products Expo West; March, 2014: Anaheim, CA. Fuzzati N. Analysis methods of ginsenosides. J Chromatogr B. 2004;812(1-2):119-133. Harnly J, Chen P, Harrington P. Probability of identification: Adulteration of American ginseng with Asian ginseng. J AOAC Int. 2013;96(6):1256-1265.