HerbalEGram: Volume 5, Number 2, February 2008

The American Herbal Products Association (AHPA), the leading trade association in the United States dealing with herbal products and supplement ingredients, announced in December of 2007 that it has added new analytical tools and methods to its website to assist manufacturers in identifying materials labeled as powdered bilberry (Vaccinium myrtillus) fruit extract that have been adulterated with Red Dye No. 2.^1,2

Concerns over bilberry extract misbranding and adulteration were raised when researchers from the company MediHerb in Australia found that the synthetic food dye Red No. 2, also known as “amaranth dye” (not related to the grain amaranth [Amaranthus spp.]) and banned from the US food supply since the 1970s, had been used to mimic the color of bilberries in ingredient samples labeled as powdered bilberry fruit extracts. The researchers published their findings in the Journal of Agricultural and Food Chemistry in 2006.³

The tools and methods that AHPA now provides on its website are intended to instruct and aid in the differentiation between genuine bilberry fruit extract and extracts adulterated with Red No. 2.¹ AHPA offers methods for detecting the presence of anthocyanins normally present in bilberry through pH manipulation and by using high performance thin layer chromatography (HPTLC). AHPA further provides information on additional resources regarding bilberry.²

“AHPA is providing methods to help enable proper evaluations of materials where identity and quality issues are known to exist,” said Steven Dentali, PhD, AHPA’s vice president of scientific and regulatory affairs, in an AHPA press release.¹ “By providing these analytical methods, we will help companies make better ingredient purchasing decisions.”

The methods and tools provided by AHPA should enable manufacturers to detect this known adulterant dye in bilberry products, but they may not necessarily detect all possible product defects. However, proper implementation of HPTLC analysis of ingredients labeled as bilberry extract by qualified personnel is likely to reveal significant variations from the normally expected chemical composition of bilberry fruit extract.

According to an article published by NutraIngredients.com in October of 2007, unconfirmed reports have been made of mulberry (Morus spp.) fruit and black bean (Phaseolus spp.) skin being used to enhance the anthocyanin content of extracts labeled as bilberry.⁴ These materials, or possibly some other misbranded ingredient, were the likely starting material for the “bilberry” samples analyzed by MediHerb.³

A study conducted by researchers from the Italian botanical extract manufacturer Indena and published in the Journal of AOAC International in 2007 found that only 15% of 40 finished bilberry products sold in Europe, Japan, and the United States that were tested in the study met their specifically-stated label claims for anthocyanin content.⁵ Moreover, 10% of the products were found to contain no anthocyanins at all. In its study, Indena recommended a new liquid chromatography method for identifying and quantifying anthocyanins and anthocyanidins in commercial bilberry extracts and products, which has been included in several pharmacopeias, including the European and Italian editions, and is under evaluation by the United States Pharmacopeia.⁴

AHPA’s tools and methods for determining adulteration of bilberry extracts with amaranth dye are available on the organization’s website, at http://www.ahpa.org/Default.aspx?tabid=164. AHPA member companies MediHerb and the Swiss analytical equipment and methods supplier CAMAG assisted in the development of the tools and methods.¹

AHPA similarly provided methods and tools for determining the purity of powdered Hoodia gordonii stems in September of 2007. An article regarding those tools and methods was published in the November issue of HerbalEGram, available here.⁶

—Courtney Cavaliere

References