Botanical Adulterants Prevention Program Publishes Grape Seed Extract Laboratory Guidance Document

The Grape Seed Extract Laboratory Guidance Document, published in February, 2019, is the result of a collaboration between Steve A. Kupina and Mark A. Kelm, PhD, from botanical ingredient manufacturer Polyphenolics, Maria J. Monagas, PhD, from the United States Pharmacopeial (USP) Convention, and Stefan Gafner, PhD from the American Botanical Council (ABC).¹ Grape seed-derived dietary supplements have been shown to improve parameters related to cardiovascular health in clinical trials. Grape seeds extracts (GSEs) are rich in proanthocyanidins (PACs), to which many of the commercially available bulk extract ingredients are standardized. Despite the relative low cost of grape seeds as a byproduct of the juice and wine industries, PACs from other plant species are available as economic adulterants. These include, for example, PACs derived from peanut (Arachis hypogaea, Fabaceae) skin or from Masson pine (Pinus massoniana, Pinaceae) bark.

The LGD provides an evaluation of the usefulness of published analytical methods to detect GSE adulteration, and summarizes the main advantages and disadvantages of each method regarding its suitability for use in a quality control laboratory. In addition to the assessment of the analytical methods, the document details the chemical composition of GSEs, potential confounding species, and known adulterants. The LGD was peer reviewed by 25 international experts from third-party contract analytical laboratories and the herbal industry.

Reference

1. Kupina SA, Kelm MA, Monagas MJ, Gafner S. Grape seed extract laboratory guidance document. Austin, TX: ABC-AHP-NCNPR Botanical Adulterants Prevention Program. 2019.