Botanical
Adulterants Program Bulletin on Adulteration of Bilberry (Vaccinium myrtillus) Extracts
By Stefan Gafner, PhD*
*American Botanical Council, P.O. Box 144345, Austin, TX 78723, email
Keywords:
Vaccinium myrtillus, bilberry
extract, adulterant, adulteration
Goal: The goal of this bulletin is to
provide timely information and/or updates on issues of adulteration of bilberry
extract to the international herbal industry and extended natural products
community in general. It is intended to complement the previously published
works with information on bilberry extract adulteration, e.g., the American
Herbal Pharmacopeia
monograph published by Upton et al,1 and the article by Foster and
Blumenthal in HerbalGram2 by presenting
new data on the occurrence of adulteration, the market situation, and
consequences for the consumer and the industry.
1
General Information
1.1
Common name: Bilberry3
1.2
Other common names:
English: European blueberry, whortleberry, huckleberry4
Chinese: Hei guo yue ju (黑果越桔)
French: Myrtille, ambroche, ambreselle,
brimbelle, gueule-noire, raisin des bois, vigne des montagnes
German: Heidelbeere, Blaubeere, Schwarzbeere, Waldbeere, Bickbeere,
Moosbeere
Italian: Mirtillo, ampulette,
asaire, bagole, baggiole,
cesarelle, giasine, lambrune, mirtillo nero, murucule
Spanish: Arándano azul, mirtilo
1.3
Accepted Latin binomial: Vaccinium myrtillus L.5,6
1.4
Synonyms: Vaccinium myrtillus var. oreophilum (Rydb.) Dorn, Vaccinium myrtillus subsp. oreophilum (Rydb.) Á. Löve, D. Löve
& B.M. Kapoor, Vaccinium oreophilum Rydb.5
1.5
Botanical family: Ericaceae
1.6
Plant part and form: Bilberry
extracts are made from fresh bilberry fruit.1 The extracts are often
standardized to 25% anthocyanidins or 36% anthocyanins. Products that claim these levels of compounds may in actuality contain the same amount as the differences are most often due to different quantitative values obtained from using different analytical techniques. In the case of bilberry, high-performance liquid chromatography (HPLC) provides a lower quantitative value than ultraviolet-visible spectrophotometry (UV/Vis).7 Also found on the market are bilberry leaf extracts, or
combinations of bilberry fruit and leaf extracts. Extracts made entirely from
bilberry leaves and properly labeled as such are not within the scope of this
document.
1.7 General use(s): The
indications for bilberry fruit include the symptomatic treatment of
dysmenorrhea associated with premenstrual syndrome, circulatory disorders in
patients with capillary leakage or peripheral vascular insufficiency, and
ophthalmic disorders.1,4,8 In addition, bilberry fruit
is used topically for mild inflammations of the oral mucosa.4,8
2
Market
2.1 Importance in the trade: In the United States, bilberry was among the top 20 herbal supplements between 2007 and 2012 in the
food, drug and mass market with annual sales above US $1.4 million in this
channel.9-13 The market volume has been fairly steady in recent years (D. Stanek oral communication, January 23, 2015).
2.2 Supply sources: Commercial
bilberries are sourced mainly from Scandinavian and Eastern European
countries. The World Blueberry Acreage & Production report lists Poland as
the major producer of bilberry, followed by Russia, Ukraine and Scandinavia. Commercial
bilberry for the production of bilberry extracts is sourced mainly from Eastern
European (Lithuania, Romania, Poland, Russia and Ukraine) and Scandinavian
(Sweden, Finland, Norway) countries, but also from France, Italy, and the
Netherlands. (D. Stanek oral communication, January 23, 2015; E. M. Martinelli
e-mail, November 16, 2015)
2.3 Raw material forms: Bilberry extracts are prepared from fresh berries that are frozen and then extracted with aqueous ethanol or aqueous methanol, and further concentrated according to the manufacturer's proprietary processes.
Generally, the extract yield is approximately 100 times lower than the initial
weight of raw material, i.e., 1 kg of fresh bilberry will provide ca. 10 grams
of bilberry dry extract (D. Stanek oral communication, January 23, 2015). Dry extract
materials using other manufacturing processes are also available.
2.4 Market dynamics: Tracking the bilberry harvest volume is
difficult as the fruit is generally harvested by local people (i.e., wildcrafted)
who then sell the fruit to brokers. A report from the North American Blueberry
Council indicates that the total harvest for wild Vaccinium species (mostly bilberry, but other Vaccinium species, e.g., bog bilberry [V. uliginosum], are collected as well) in Europe was 11,340 metric
tons (25 million lbs.) in 2008, 7,710 metric tons (17 million lbs.) in 2010,
and 19,500 metric tons (43 million lbs.) in 2012.14
For 2012,
the harvest in Poland was around 10,000 metric tons, but the harvest was mainly
destined for the domestic market for confectionary and baked goods. Russia,
Ukraine, and Scandinavia provided at least an additional 6,000 metric tons to
the overall harvest.14 According to the report, the harvest in 2012
was particularly strong despite unfavorable weather conditions; since the
economy was depressed in European countries, many people harvested wild
blueberries for additional revenue.
3
Adulteration
3.1
Known adulterants: Materials
that are used to adulterate bilberry extracts typically have an
intensive dark blue color, such as anthocyanidin-containing extracts or red
food coloring such as amaranth dye (FD&C Red 2, E 123). Anthocyanidin-rich
extracts known to be used as substitute for bilberry include those from bog
bilberry (Vaccinium uliginosum),
lingonberry (V. vitis-idaea), blueberry species (V.
angustifolium, V. corymbosum, V. floribundum), cranberry (V. oxycoccos and V. macrocarpon), raspberries (Rubus spp., Rosaceae), wild cherry (Prunus avium, Rosaceae), black chokeberry (Aronia melanocarpa,
Rosaceae), European elder (Sambucus
nigra, Adoxaceae) berry, black soybean (Glycine max, Fabaceae)
hull, black rice (Oryza sativa, Poaceae), and mulberry species (Morus australis, M. nigra, Moraceae).2,15-18
The
common names “blueberry” and “wild blueberry” have different meanings depending
on the geographical location. In the US dietary supplement trade, the name
“blueberry” is restricted to three species, Vaccinium
angustifolium, V. corymbosum, and
V. pallidum.3 In Europe, V.
myrtillus is often called blueberry, though bilberry is the English word
which refers to this species in the trade.3 The hybrid cultivated
blueberries from which the majority of the commercial food supply is derived
are generally called blueberries. North American wild blueberry, common
blueberry, common lowbush blueberry, low sweet blueberry, and lowbush blueberry
refer to V. angustifolium which grows in the Northeastern U.S. and is
commercially harvested in its habitat. Velvet leaf blueberry (V.
myrtilloides) is also
traded as “wild blueberry,” and is mostly wild-harvested in the Canadian
maritime provinces. It is safe to assume that “wild blueberry” in a commercial
sense refers to both V. angustifolium and V. myrtilloides (Steven
Foster, e-mail, July 1, 2015).
3.2 Sources of information confirming adulteration: There
have been a number of publications on bilberry adulteration, such as the
reviews by Foster and Blumenthal,2 Giacomelli et al.,16
Upton et al.,1 the presentation by Pace et al.,19 and the
doctoral thesis by Primetta.20 Foster and Blumenthal distinguish
between the deliberate adulteration of bilberry extracts by addition of
extracts from anthocyanin-rich sources such as blueberry, cranberry, European
elder, sweet cherry, and others, and the adulteration occurring in the markets
in China, where extracts of lingonberry
and bog bilberry are wild-harvested and offered as “homemade Chinese
bilberry” and “Chinese domestic bilberry” extracts at prices as low as $10/kg.2
This is in contrast to the much more expensive authentic bilberry extract (see section 3.3 below). Two additional studies regarding adulteration of commercial bilberry extracts were published in 2013 and 2014.15,21
The investigation into the quality of 20 dietary supplements purchased in a
store or over the Internet in Japan by ultra high-performance liquid
chromatography (UHPLC) with detection by visible light at 535 nm provided
evidence for adulteration in one sample. The product in question was labeled to
contain a mixture of bilberry and black currant (Ribes nigrum, Grossulariaceae) extracts, but instead consisted
entirely of black currant.21 Gardana et al. analyzed 26 commercial
bilberry materials including 14 bulk extracts, six food supplements, and six
juices by UV/Vis spectrophotometry and by UHPLC using a photodiode array
detector (DAD). The samples were purchased either directly from the supplier
(bulk extracts), or from herbal shops and local markets in Italy. The authors found an admixture of black mulberry in five samples (two extracts, three food
supplements), and substitution of bilberry with chokeberry in two extracts and
with a material tentatively identified as blackberry (Rubus spp.) in one extract. One food supplement did not contain any
anthocyanins at all. Five of the juices were consistent with products made from
bilberry fruit, while one juice did not contain measurable amounts of
anthocyanins.15
3.3
Accidental or intentional adulteration: The limited supply and high commodity prices of bilberry
raw materials have created an incentive for economically-motivated
adulteration. In 2015 authentic bilberry extracts sold for a price of US $600-800/kg
extract (D. Stanek oral communication, January 23, 2015). More easily
accessible anthocyanin-containing fruit species can be collected in larger amounts than bilberry in a
comparatively short time since many of these are readily available from cultivated rather than more expensive wild sources. The fruit from these other species can be made into
extracts at a significantly lower cost than bilberry and can be priced below bilberry
market rates while producing a profit for the producer/seller.
3.4
Frequency of occurrence:
There are very little data on the extent of
adulteration of commercial bilberry extracts and dietary supplements. A presentation
by Pace et al. suggested that “adulteration of bilberry is
rampant”;19 Roberto Pace, PhD, Director of Quality Control at Indena
S.p.A. (Milan, Italy), the world's leading marketer of bilberry extract whose use has been confirmed in clinical trials, commented that “bilberry is one of the most economically
adulterated ingredients of the health food market” (R.
Pace oral communication, November 5, 2015). As noted above, one study included results of 20 commercial
products purchased in Japan, with only 13 of the products labeled to contain
bilberry. Of these 13 products, one was found to be entirely composed of black
currant, while the remainder did contain authentic bilberry.21 Another
study looked at bilberry extracts from different manufacturers and supplements
purchased on local markets in Italy. The results indicated that six out of 14
extracts, and four out of six supplements were adulterated.15 Lee
analyzed 15 commercial bilberry supplements purchased in the states of
Washington and Idaho in the United States. Five products contained authentic
bilberry material, and two samples could not be evaluated because they were
composed of a mixture of anthocyanin-containing fruits, including bilberry. The
remaining eight products were found to be adulterated.18 Based on
the limited published data available, it is not possible to come to any
conclusions about the frequency of bilberry adulteration, but it is accurate to say that it is not uncommon.
3.5 Possible safety/therapeutic issues: Most of the known adulterants of
bilberry have a long-standing history of safe use in food and therefore do not
represent a safety concern. However, adulteration of bilberry extracts with
amaranth dye is of possible safety concern. Amaranth dye has been prohibited
for use by the US Food and Drug Administration (FDA) since 1976 due to concerns
about carcinogenicity, which are mainly based on two controversial studies in
rats.22,23 The use of amaranth dye is still permitted in Europe, but
is limited to 0.15 mg/kg per day.24 Most botanical adulterants are
cultivated plants, and might be potentially contaminated by pesticides, largely
used in the growing of berries. Conversely, pesticides are not an issue with
wild-harvested bilberry.
3.6 Analytical methods to detect
adulteration: The
most suitable way to authenticate bilberry extracts and detect adulteration is
by chemical analysis based on the specific anthocyanin fingerprint using either
high-performance thin layer chromatography (HPTLC) or high-performance liquid
chromatography (HPLC) with ultraviolet/visible (UV/Vis) and/or mass
spectrometric (MS) detection. The monograph of the United States Pharmacopeia (USP)26 recommends use of HPLC, while that of the American Herbal Pharmacopoeia (AHP)1 and European Pharmacopoeia (EP)27 utilize the UV/Vis method after adequate identification tests have been performed. The use of UV/Vis spectrophotometry alone will allow measurement
of total anthocyanins in bilberry extracts, but is not specific enough as an
identity test. It can be applied as a quantitative tool only after the identity of the raw material has been assured. A comprehensive evaluation of 39 publicly available methods for
the authentication and detection of adulterants in bilberry extracts, the
Bilberry Extract Laboratory Guidance Document, is available through the
ABC-AHP-NCNPR Botanical Adulterants Program.25
3.7 Perspectives: Don Stanek, US Sales Director at Linnea
Inc., a European producer of bilberry extract, commented that adulteration of
bilberry extracts is likely to persist, since the authentic material is so expensive (oral communication, January 23, 2015). Furthermore,
explains Giovanni Appendino, PhD, professor of pharmaceutical sciences at the
University of Eastern Piedmont (Novara,
Italy) and consultant to Indena, the leading producer of bilberry extract, the
price of the berries is subjected to significant variations due to the effect
of climate on the labor-intensive harvest (e-mail, July 20, 2015).
4
Conclusions: The
adulteration of bilberry extracts continues to afflict the natural products industry.
Since the raw material is harvested in the wild, the control of the supply
chain is more challenging and adequate testing of the incoming raw material is
crucial. Test methods outlined, e.g., in the USP,26 the EP,27 or in the AHP1 are able to detect
adulteration of bilberry extracts and should be in place in every quality
control laboratory to prevent manufacturers of bilberry extract products from
becoming victims of companies providing fraudulent ingredients.
5
References
- Upton
R, Graff A, Petrone C, Swisher D. American Herbal Pharmacopoeia and Therapeutic
Compendium: Bilberry Fruit. Vaccinium myrtillus L.: Standards of Analysis,
Quality Control and Therapeutics. Scotts Valley, CA: American Herbal
Pharmacopoeia; 2001.
- Foster S, Blumenthal. The adulteration of commercial bilberry extracts. HerbalGram. 2012;96:63-74. Available at: http://cms.herbalgram.org/herbalgram/issue96/hg96-feat-bilberry.html. Accessed February 14, 2015.
- McGuffin
M, Kartesz JT, Leung AY, Tucker AO. American Herbal Products Association’s Herbs
of Commerce. 2nd ed. Silver Spring, MD: American Herbal Products Association;
2000.
- Blumenthal
M, Goldberg A, Brinckmann J (eds). Herbal Medicine: Expanded Commission E
Monographs. Austin, TX: American Botanical Council; Newton, MA: Integrative
Medicine Communications; 2000:16-21.
- The
Plant List. Version 1.1 (September 2013). Available at: http://www.theplantlist.org. Accessed February
24, 2015.
- Tropicos.org.
Missouri Botanical Garden. Available at: http://www.tropicos.org.
Accessed February 24, 2015.
- Artaria
C, Pace R, Maramaldi G, Appendino G. Different
brands of bilberry extract: A comparison of selected components.
Nutrafoods. 2007;6:13-18.
- World
Health Organization: WHO monographs on selected plants, Volume 4. Fructus
Myrtilli. WHO Press 2009;210-225.
- Cavaliere
C, Rea P, Blumenthal M. Herbal supplement sales in United States show growth in
all channels. HerbalGram.
2008;78:60-63. Available at: http://cms.herbalgram.org/herbalgram/issue78/article3263.html.
Accessed February 14, 2015.
- Cavaliere
C, Rea P, Lynch ME, Blumenthal M. Herbal supplement sales experience slight
increase in 2008. HerbalGram.
2009;82:58-61. Available at: http://cms.herbalgram.org/herbalgram/issue82/article3400.html.
Accessed February 14, 2015.
- Cavaliere
C, Rea P, Lynch ME, Blumenthal M. Herbal supplement sales rise in all channels
in 2009. HerbalGram. 2010;86:62-65.
Available at: http://cms.herbalgram.org/herbalgram/issue86/article3530.html.
Accessed February 14, 2015.
- Blumenthal
M, Lindstrom A, Lynch ME, Rea P. Herbs sales continue growth – up 3.3% in 2010.
HerbalGram. 2011;90:64-67. Available at: http://cms.herbalgram.org/herbalgram/issue90/MarketReport.html.
Accessed February 14, 2015.
- Blumenthal
M, Lindstrom A, Ooyen C, Lynch ME. Herb supplement sales increase 4.5% in 2011.
HerbalGram. 2012;95:60-64. Available
at: http://cms.herbalgram.org/herbalgram/issue95/hg95-mktrpt.html.
Accessed February 14, 2015.
- Brazelton
C. 2012 World Blueberry Acreage and
Production Report. North American Blueberry Council. 2013.
- Gardana C, Ciappellano
S, Marinoni L, Fachechi C, Simonetti P. Bilberry adulteration: identification
and chemical profiling of anthocyanins by different analytical methods. J Agric Food Chem. 2014;62(45):10998-11004.
- Giacomelli L, Appendino
G, Franceschi F, Togni S, Pace
R. Omne
Ignotum pro Magnifico: characterization of commercial Bilberry extracts to
fight adulteration. Eur Rev Med Pharmacol
Sci. 2014;18(24):3948-3953.
- Filippini R,
Piovan A, Caniato R. Substitution
of Vaccinium myrtillus L. for Aronia melanocarpa (Michx.) Elliott in a commercial
batch. Plant Biosyst. 2011;145(1):175-181.
- Lee J. Anthocyanin analyses of Vaccinium fruit dietary supplements. Food Sci Nutr. 2016. doi: 10.1002/fsn3.339.
- Pace R,
Morazzoni P, Appendino G. Omne
ignotum pro magnifico:
Getting bilberry out of the adulteration swamp. Talk presented at: 9th
Oxford International Conference on the Science of Botanicals; April 14, 2010;
Oxford, MS.
- Primetta
A. Phenolic compounds in the berries
of the selected Vaccinium species - the potential for authenticity
analyses. PhD thesis. Kuopio, Finland: University of Eastern Finland;
2014.
- Yamamoto M, Yamaura K, Ishiwatari M, et al. Degradation index for
quality evaluation of commercial dietary supplements of bilberry extract. J Food Sci. 2013;78:S477–S483.
- Andrianova
MM. Carcinogenous properties of red food pigments - amaranth, SX purple and 4R
purple, Vop. Pitan. 1970;29:61-65.
- Baigusheva
MM. Carcinogenic properties of the amaranth paste, Vop. Pitan. 1968:27:46-50.
- European Food Safety Authority. Scientific Opinion
on the re-evaluation of Amaranth (E 123) as a food additive. EFSA Journal. 2010;8(7):1649.
- Gafner
S. Bilberry Extract Adulteration
Laboratory Guidance Document. ABC-AHP-NCNPR Botanical Adulterants Program,
Austin, TX. 2015. http://cms.herbalgram.org/BAP/LGD/BilberryLabGuidanceDocument.html. Accessed August 25, 2015.
- United
States Pharmacopeial Convention. Powdered Bilberry Extract. In: USP 37-NF
32. Rockville, MD: United States Pharmacopeial Convention. 2014.
- The European Directorate for the Quality of
Medicines. European
Pharmacopoeia (EP
7.5). Myrtilli fructus recentis extractum
siccum raffinatum et normatum. Strasbourg, France: Council of Europe;
2012:1130-1132.
REVISION SUMMARY
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