Oregano is a popular herb both for culinary use and for use in dietary supplements; the 2018 Herb Market Report published inHerbalGramfound that oregano was the 10thtop-selling dietary supplement in 2017.
One issue, the press release notes, is that a large number of plant species have the term “oregano” as part of their common name, and can therefore be mistakenly sold instead of oregano. Some of these species are legally allowed to be used interchangeably, depending on the intended use, while others are considered to be adulterants.
Another problem is the substitution of oregano with undeclared lower-cost plant materials used as bulking agents, including strawberry leaf, myrtle leaf, olive leaf, and thyme, to name a few.
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When it comes to oregano essential oil, there are reports of admixture of other lower-cost essential oils with oregano oil, as well as the addition of the pure compounds carvacrol, thymol, or limonene, which naturally occur in true oregano essential oil, but can be made by chemical synthesis.The bulletin was written by Ezra Bejar, Ph.D., an expert in botanical research based in San Diego, CA. It lists the known adulterants, summarizes analytical approaches to detect adulterants, and provides useful information regarding oregano.
Stefan Gafner, Chief Science Officer of ABC and Technical Director of BAPP, commented in the release: “On 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.”
The BAPB is freely accessible to all,here.