FWD 2 Bilberry Extract Laboratory Guidance Document

Bilberry Extract Laboratory Guidance Published by ABC-AHP-NCNPR Botanical Adulterants Program

Quality consortiums second Lab Guidance Document reviews 39 laboratory methods for the analysis of bilberry extract to ensure proper identity and detection of possible adulterants

(Austin, Texas, August 12, 2015) The ABC-AHP-NCNPR Botanical Adulterants Program announces the publication of its new Laboratory Guidance Document (LGD) on Bilberry (Vaccinium myrtillus) fruit extract. This is part of the Program’s new series of comprehensive, authoritative, extensively peer-reviewed, and up-to-date summaries and assessments of laboratory analytical methods for authentication of the identity of botanical ingredients and detection of the potential presence of known adulterants.

The Program’s bilberry LGD is the second publication in its Laboratory Guidance Document series for botanical ingredients. It follows January’s inaugural LGD publication on skullcap (Scutellaria lateriflora) herb. There is ample evidence from published and unpublished laboratory reports that both of these herbs are subject to adulteration in the US and international markets.

The LGDs are intended for use by quality control personnel and lab technicians in the herbal medicine, botanical ingredient, and dietary supplement sectors of industry to help them choose the most appropriate techniques and methods for their specific analytical needs.

The LGDs are available to members of industry, researchers, health professionals, and the general public at no cost as part of the Botanical Adulterants Program’s policy of producing freely available educational documents on adulteration, made possible through funding by the Program’s underwriters and supporters.

The American Botanical Council (ABC)-American Herbal Pharmacopoeia (AHP)-National Center for Natural Products Research (NCNPR) Botanical Adulterants Program (BAP) is an international consortium of nonprofit organizations, analytical laboratories, professional scientists, industry members, professional and trade organizations, and others that advises industry, researchers, health professionals, and the public about the various challenges related to adulterated herb and botanical ingredients sold in commerce. To date, more than 165 American and international parties have financially supported or otherwise endorsed the Program.

“For the first several years of our Program, we published articles alerting members of the herb industry about adulteration of specific herbs,” said Mark Blumenthal, founder and executive director of the American Botanical Council and director of the BAP. “Now, in addition to our soon-to-be-enhanced series of publications on adulterated herbs, we are offering technical resources to assist industry and third-party laboratories to detect adulteration and help prevent adulterated botanical ingredients and extracts from being processed into finished consumer products.”

The ABC-AHP-NCNPR Laboratory Guidance Documents are intended to provide reliable, expert guidance on suitable methods to comply with the mandated requirements of testing for identity, purity, strength, and composition outlined in the US Food and Drug Administration’s current Good Manufacturing Practices (cGMPs) for dietary supplements, as well as government-mandated GMPs in other countries. Per the US cGMPs, it is the responsibility of the dietary supplement manufacturers to “conduct at least one appropriate test or examination to verify the identity of any component that is a dietary ingredient.”1

The Program’s LGDs provide information about the most suitable analytical methods for detection of certain adulterants and authentication of specific botanical materials in the form of whole, cut, or powdered raw materials, extracts, and essential oils. Conclusions are based on a thorough review of available analytical methods (e.g., from official and unofficial compendia, as well as the peer-reviewed literature) and input from peer reviewers from academia, government, and industry in multiple countries. The Bilberry Fruit Extract LGD was peer-reviewed by 16 such experts. The primary assessment of each method is based on its performance characteristics (i.e., suitability in detecting known adulterants, if they are present in a tested material); labor and analysis time comprise the secondary evaluation criteria.

Stefan Gafner, PhD, ABC chief science officer and BAP technical director, emphasized the importance of having a solid analytical method to evaluate bilberry raw materials and finished products: “Based on comments from dietary supplement ingredient suppliers and manufacturers, the adulteration of bilberry extracts is a big concern in the herbal industry. Bilberries are a rich source of anthocyanins — naturally occurring blue-purple pigments with antioxidant and other beneficial properties found in many fruits and berries — but manufacturing a high-quality bilberry extract is very expensive due to the high cost of bilberries. People who intend to cheat have a number of cheaper anthocyanin sources available, making the discovery of adulteration sometimes challenging. Therefore, it is important to use an analytical method that is specific enough to detect the potential adulterants.”

The BAP’s LGDs begin with a statement of purpose and scope in regard to the particular plant species covered, followed by a short overview of the botanical nomenclature of the species and its known adulterants. Also included are sections on analytical techniques (generally including macroscopic, microscopic, chemical, and genetic assays) and a phytochemical composition overview of the species and known adulterants. The LGDs conclude with a concise table of strengths and limitations of the various assays. Complete references are provided with links to original source documents.

The next LGD scheduled to be released by the ABC-AHP-NCNPR Botanical Adulterants Program is on the detection of black cohosh (Actaea racemosa) adulteration.

For the bilberry extract LGD, 39 analytical methods were evaluated, including macroscopic analysis, botanical microscopy, HPTLC, HPLC/UHPLC, and UV/Vis spectrophotometry.

“The review is accurate and it is a valuable guidance on analytical methods to authenticate bilberry extracts and to detect adulteration,” commented Roberto Pace, PhD, director of quality control at Indena S.p.A. in Milan, Italy, after reviewing the bilberry LGD. “I deem it will be one of the main references on the analytics of bilberry.”

To date, the ABC-AHP-NCNPR Botanical Adulterants Program has published five extensively peer-reviewed and referenced articles on the history of adulteration, adulteration of the herbs black cohosh and skullcap, and adulteration of bilberry fruit extract and so-called “grapefruit seed extract.” These open-access articles are available on the Program’s webpage. The Program also publishes a quarterly e-newsletter, the Botanical Adulterants Monitor, that highlights new scientific publications related to botanical authenticity and analysis to detect possible adulteration, recent regulatory actions, and Program news.


1. US Food and Drug Administration. Code of Federal Regulations Title 21, Volume 2, Part 111 (21CFR111): Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements. Available at: www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?CFRPart=111. Revised April 1, 2014. Accessed July 22, 2015.