Botanical Adulterants Prevention Program Produces Oregano 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. Oregano extracts and oregano essential oil are also popular as dietary supplement ingredients. Besides its use in dietary supplements, oregano essential oil is included as an ingredient in formulations of the perfume and cosmetic industry.

The most important authenticity issue is the substitution of oregano herb with undeclared lower-cost plant materials to add volume (bulking agents), which include the leaves of Cistus spp., hazelnut (Corylus avellana), strawberry (Fragaria spp.), myrtle (Myrtus communis), olive (Olea europaea), sumac (Rhus spp.), and the aboveground parts of sweet marjoram (Origanum majorana), summer savory (Satureja hortensis), winter savory (Satureja montana), and thyme (Thymus spp.). Such inappropriate substitution and mislabeling appears to be fairly common, according to a number of articles published over the last decade, which are referenced in the new bulletin.¹ Also discussed in the bulletin is adulteration of oregano essential oil, which includes admixture of other, lower-cost essential oils with oregano oil, as well as the addition of the pure compounds carvacrol, thymol, or limonene (naturally occurring characteristic chemical compounds found in true oregano essential oil which are sometimes made by chemical synthesis).

The oregano bulletin¹ was written by Ezra Bejar, PhD, an expert in botanical research in San Diego, California, and reviewed by 19 experts from the nonprofit research sector, contract analytical laboratories, and the herb industry.

Reference

1. Bejar E. Adulteration of oregano herb and essential oil. Botanical Adulterants Prevention Bulletin. Austin, TX: ABC-AHP-NCNPR Botanical Adulterants Prevention Program. 2019: 1-10.