Validation of chemometric methods for plant authentication

The authenticity of botanical ingredients in marketed products has been the focus of widespread concern in the natural product and dietary supplement industry. Classically, plants are identified by physical examination of minimally processed biomass for diagnostic macroscopic and microscopic features. However, botanical ingredients in modern ingredient supply chains are harvested when floral parts are absent, utilize parts of the plant that lack flowers (e.g., roots) or are so highly processed that diagnostic anatomical features have been destroyed or removed (e.g., extracts). Chemical profiling of extracts with chemometric analyses shows promise as an approach for authenticating botanicals. Adulteration of ginseng (Panax spp.) roots with Panax leaves is a common and attractive adulteration as leaves are considered useless by-products of ginseng cultivation despite having higher ginsenoside content than roots, thereby giving the false appearance of higher quality and potency.

Chemical profiling by HPLC-UV shows unique chemical profiles for leaf versus root materials and using SIMCA it is possible to differentiate root from leaf and to detect high levels of adulteration. However using a new multivariate moving window PCA approach has allowed us to detect much lower levels of adulteration in products based on the PC score residuals of unknown samples. This represents a significant improvement over past statistical techniques that resulted in significantly improved detection limits compared with traditional regression models for detection of low level of contamination [1].

Acknowledgements: Funding provided by Canada Research Chairs.

Keywords: metabolomics, authenticity, identification, panax, ginseng.

References:

[1] Pace R, Martinelli EM, Sardone N, D E Combarieu E. Metabolomic evaluation of ginsenosides distribution in Panax genus (Panax ginseng and Panax quinquefolius) using multivariate statistical analysis. Fitoterapia 2015; 101: 80 – 91