Botanical Adulterants Monitor: Issue 20, September 2020
Adulteration
of European Elder Berry Extracts on the Rise
Herbal dietary supplement
manufacturer Nature’s Way (Green Bay, WI) has shared data from their in-house
investigation into the authenticity of commercial bulk and finished dietary
supplement products labeled to contain European elder (Sambucus nigra, Adoxaceae)1
berry extracts. Twenty-five bulk extracts and eight finished products were
analyzed by high-performance thin-layer chromatography (HPTLC),
high-performance liquid chromatography with visible detection (HPLC-Vis), and UV/Vis
spectrophotometry. The latter assay was used solely to determine total
anthocyanins in the products. Test methods were in accordance with those published
in the United States Pharmacopeial (USP) monograph on European elder berry dry
extract,2 the HPTLC Association,3 and the Institute for
Nutraceutical Advancement (INA).4
In parallel, the scientists
analyzed possible adulterants, including blueberry (Vaccinium angustifolium, V.
corymbosum, or V. pallidum,
Ericaceae), black chokeberry (Aronia melanocarpa,
Rosaceae), amaranth dye, and black rice (Oryza
sativa, Poaceae) extract, among others, using the same methods. The
identity was assessed by HPTLC, and by the HPLC anthocyanin profile. Criteria
included an assessment of the intensity of cyanidin-3-O-sambubioside signal, and the presence of
cyanidin-3-O-sambubioside-5-O-glucoside. Of the 25 bulk materials, 14
failed the identity test (very low amounts of cyanidin-3-O-sambubioside compared to other
anthocyanins), and five were found to contain no elder berry extract at all.
Black rice extract was found as an adulterant in at least two cases. Among the
eight finished elder berry dietary supplements, two products were devoid of
elder berry extract. One contained mainly a substance similar to oat bran,
while the other was made of Vitamin C, and excipients. Both adulterated
products were visually distinct from authentic elder berry products with a
white or orange color, respectively.
Comment: With the recent
increase in sales volumes of European elder berry dietary supplements in the
United States and elsewhere, and shipment delays of authentic elder berry bulk
ingredients due to the COVID-19 pandemic, manufacturers have experienced
difficulties in obtaining high-quality elder berry bulk extracts. Not surprisingly,
there are some fraudulent suppliers which sell adulterated ingredients, trying
to take advantage of the use of non-specific quality control methods (e.g., UV-Vis)
for identity testing by some companies in the herbal dietary supplement
industry and even some companies without quality control systems. According to
Travis Borchardt, Vice-President of Product Integrity and Compliance at
Nature’s Way, elder berry adulteration is a relatively recent occurrence, and
appears to be linked to the commercial success of the ingredient over the past
3-4 years, i.e., before the outbreak of the COVID-19 pandemic, although it is
quite likely that the increase in its demand during the pandemic has resulted
in even further attempts by unscrupulous suppliers to offer fraudulent
material. Adulteration of elder berry extracts is readily detected using the
HPTLC profile, or the HPLC-Vis anthocyanin fingerprint.
References
- Sambucus nigra. Medicinal Plant Names
Services. Kew, Richmond, United Kingdom. https://mpns.science.kew.org/mpns-portal/backToSearch?query=sambucus+nigra&filter=&fuzzy=false&nameType=all. Accessed August 28,
2020.
- European elder berry dry
extract. USP 43-NF 38. Rockville, MD: United
States Pharmacopeial Convention; 2020:4978.
- European elder flower (Sambucus nigra). HPTLC Association. https://www.hptlc-association.org/methods/methods.cfm. Accessed
August 28, 2020.
- Institute for Nutraceutical
Advancement. Anthocyanin content in bilberry by pH-differential
spectrophotometry. INA Method 116.000.