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
1.
Foster S. Toward an understanding of ginseng adulteration:
the tangled web of names, history, trade and perception. HerbalGram.
2016;111:36-57.
2.
Kilham
C, Bily A. Adulteration of herbs: a matter of global importance. Presented at:
Natural Products Expo West; March, 2014: Anaheim, CA.
3.
Fuzzati
N. Analysis methods of ginsenosides. J Chromatogr B.
2004;812(1-2):119-133.
4.
Harnly
J, Chen P, Harrington P. Probability of identification: Adulteration of
American ginseng with Asian ginseng. J AOAC Int.
2013;96(6):1256-1265.