The Botanical Adulterants Prevention Program (BAPP) is a joint effort of the American Botanical Council, the American Herbal Pharmacopoeia and the National Center for Natural Products Research at the University of Mississippi. BAPP has now published more than 50 bulletins, lab guidance documents and other papers.
The bulletin found a significant amount of extraneous material is making its way into shipments labeled as oregano. This includes the substitution of oregano herb with undeclared lower-cost plant materials to add volume (bulking agents), including the following plants: Cistus spp. leaf, hazelnut (Corylus avellana) leaf, strawberry (Fragaria spp.) leaf, myrtle (Myrtus communis) leaf, olive (Olea europaea) leaf, sweet marjoram (Origanum majorana) herb, sumac (Rhus spp.) leaf, summer savory (Satureja hortensis) herb, winter savory (Satureja montana) herb, and thyme (Thymus spp.) herb. Such inappropriate substitution and mislabeling appears to be fairly common according to a number of articles published over the last decade, many of which are referenced in the new bulletin.
Oregano (Origanum vulgare subsp. hirtum; O. onites) is one of the most popular herbs for culinary use especially in countries of the Arabian Peninsula, Europe, North Africa, and North America. Powdered oregano herb, herb extracts, and oregano essential oil are also popular as dietary supplement ingredients, which in the United States are primarily sold in natural retail stores, where oregano dietary supplements were the 10th top-selling dietary supplement with annual retail sales totaling roughly $10 million in 2017, according to ABC’s 2018 Herb Market Report which was published HerbalGram, ABC’s monthly journal.
In addition to outright economic adulteration, there could be cases of simple mistaken identity, which could call into question the quality control in certain supply chains. A large number of plant species have the term “oregano” as part of their common name and therefore can be mistakenly sold instead of oregano. Some of these species are legally allowed to be used interchangeably, depending on their sale as a spice, dietary supplement, or cosmetic ingredient, the bulletin notes.
Stefan Gafner, PhD, chief science officer for ABC and head of BAPP, said oregano adulteration is a global issue.
“The main supplier is Turkey. It’s by far the biggest supplier worldwide,” Gafner told NutraIngredients-USA. “But if you look at the spice market in the US, a large proportion of that is Mexican oregano.”
Lack of clarity about where adulterated materials end up
Gafner said that while there is ample evidence for significant economic adulteration in the oregano supply chain, it is less clear where the adulterated lots of material are ending up. There is a lot info about the herb itself, but less clarity when it comes to the essential oil made from the herb.
“In the past, researchers have mainly investigated the authenticity of oregano as a spice, where the addition of undeclared other plant materials appears to be quite widespread. It is not clear if these fraudulent practices are also occurring in the dietary supplement supply chain which is dominated by extracts and essential oil products. If so, we hope that the oregano bulletin will provide companies in the oregano trade with helpful information to enable the detection of adulterated raw materials,” Gafner said.
The new bulletin, written by Ezra Bejar, PhD, an expert in botanical research in San Diego, California, lists the known adulterants, summarizes current analytical approaches to detect adulterants, and provides information on the nomenclature, supply chain, and market importance of oregano. It also discusses safety aspects of the known adulterants. The BAPB was reviewed by 19 experts from the nonprofit research sector, contract analytical laboratories, and the herb industry.