Intentional Adulteration of Plant-Based Products – Understanding, Detecting, and Preventing a Major Scientific and Economic Fraud
Scientific analysis of the adulteration of essential oils and plant extracts: types of fraud, health impacts, analytical methods, and regulatory responses.
Esméralda Cicchetti
1/15/20266 min read
Intentional Adulteration of Plant-Based Products - Understanding, detecting and preventing a major scientific and economic fraud
Adulteration of plant-based products refers to the intentional modification of a botanical raw material for economic gain, a phenomenon known as EMA (Economically Motivated Adulteration).
It can take several forms: dilution, botanical species substitution, addition of synthetic compounds, targeted enrichment of analytical markers, or blending with lower-quality raw materials.
In the essential oils and plant extract sector, adulteration is now one of the main challenges in authentication and quality control.
Types of adulteration in plant products and their extracts
Many scientific studies have documented the strategies used to bypass analytical controls and mislead consumers. The observed patterns are similar for crude botanicals and their extracts.
Botanical species substitution (mislabeling)
This is the most frequent practice: a lower-value species is sold under the name of a higher-value species.
Documented examples:
Eucalyptus: cineole-rich fractions from Cinnamomum camphora or Cinnamomum longepaniculatum sold as Eucalyptus globulus.
Mint: Mentha arvensis oil marketed as Mentha × piperita.
Anise: Illicium verum oil presented as green anise (Pimpinella spp.).
Boswellia: substitution between Boswellia serrata, B. papyrifera and B. sacra.
Total substitution: imitations and counterfeits
The product is fully replaced by a cheaper substitute, either synthetic or of different botanical origin.
a. Synthetic analogues
Wintergreen essential oil replaced by synthetic methyl salicylate.
Products sold as sandalwood consisting entirely of synthetic aromatic compounds.
b. Reconstituted oils
Some high-value oils (rose, neroli, lemon balm, lavender) may be fully reconstructed by blending natural fractions, isolates, and synthetic molecules in order to reproduce an expected chromatographic profile.
Examples:
Lemon balm reconstituted from lemongrass, Litsea cubeba, and synthetic isolates.
“Lavender 40/42” adjusted with synthetic linalool and linalyl acetate, sometimes marketed under an INCI suggesting a pure oil.
c. Physical imitations
Fake Cordyceps made from flours and pigments.
Cinnamon leaf powders sold as bark.
Clove stems and leaves sold as flower buds.
Partial substitution: dilution and cutting
The most common form because it is harder to detect, especially when the adulterant is added at low levels.
a. Blending with related species
True lavender (L. angustifolia) cut with lavandin or spike lavender.
Oregano mixed with myrtle, olive, or cistus leaves.
Black pepper cut with papaya seeds.
b. Addition of diluents
Vegetable oils or solvents (e.g., dipropylene glycol).
Syrups added to honey.
Starchy materials in coffee.
c. Targeted fortification
Addition of isolates (natural or synthetic) to artificially adjust an analytical profile:
Linalool and linalyl acetate added to lavender.
Vanillin added to vanilla.
Quality frauds
Invisible diluents: addition of vegetable or mineral oils increasing volume without obvious chromatographic change in routine analysis.
Visual masking: industrial dyes (e.g., Sudan I–IV, Rhodamine B) used to intensify spice coloration.
Spent materials: reuse of already-extracted plant material, resulting in products depleted of active compounds.
Geographical origin fraud
Exploitation of regional reputation:
Asian lavenders labeled as French or Bulgarian.
Brazilian sweet orange presented as Florida origin.
Saffron sold with national origin claims without AOP certification.
Misrepresentation of production method and quality:
Fake “organic” products.
“Sun-dried” claims without evidence.
Marketing use of non-regulated terms such as “therapeutic grade”.
Health, economic, and pharmacological consequences of adulteration
Adulteration of plant-based products has severe and multidimensional consequences extending far beyond financial deception. The literature classifies these impacts into four major categories: public health risks, economic damage, loss of therapeutic efficacy, and erosion of consumer trust.
Impacts on health and public safety
This is the most critical impact. Adulteration can introduce hazardous substances into the supply chain:
Direct toxicity: Addition of heavy metals such as lead (as rods or solutions) in Cordyceps to increase weight has caused severe poisoning cases. Use of diethylene glycol (DEG), a lethal solvent, in glycerin has historically caused mass fatalities.
Undeclared allergens: Substitution with proteins from nuts, almonds, soy, or gluten in spices (cumin, paprika, curry) can trigger anaphylactic shock in sensitive individuals.
Carcinogenicity: Use of banned industrial dyes such as Sudan I–IV or Rhodamine B in powdered spices remains frequent despite their carcinogenic classification.
Drug interactions: Presence of undeclared plant species may interfere with prescribed medications (e.g., anticoagulants such as warfarin), leading to severe adverse effects such as multiorgan failure or hemorrhage.
Economic impacts and market destabilization
Adulteration is primarily profit-driven but damages the entire industrial ecosystem:
Unfair competition: Fraudsters selling adulterated low-cost products disadvantage honest suppliers who cannot match prices due to higher production costs.
National economic destabilization: Countries dependent on high-value exports (e.g., French lavender, saffron) may suffer disrupted trade and reduced national income.
Fraud management costs: Companies must invest heavily in analytical equipment and audits, increasing final product prices.
Loss of efficacy and psychophysiological impacts
An adulterated product does not deliver its intended health or therapeutic function:
Spent materials: Use of exhausted plant residues leads to biologically inactive products lacking active constituents.
Reduced biological activity: Dilution with solvents such as dipropylene glycol reduces antimicrobial and antifungal activity.
Altered physiological effects (essential oils): Addition of synthetic molecules distorts natural chiral ratios, potentially reversing expected effects (e.g., a relaxing oil becoming stimulating or increasing blood pressure).
Impact on trust and ethics
Accumulated fraud undermines the relationship between industry and consumers:
Erosion of trust: Consumers disappointed by ineffective or adverse products may reject the entire natural product category.
Brand reputation risk: A company may become involved in scandals if CoAs are not rigorously verified, leading to recalls and legal action.
To mitigate these impacts, programs such as BAPP recommend mandatory destruction of “irreparably defective articles” rather than returning them to suppliers, preventing resale to less vigilant companies.
HOW TO RESPOND TO ADULTERATION?
Facing increasing fraud sophistication, responses are structured across multiple levels involving private stakeholders, public authorities, and consumer protection organizations.
Industry: strengthening controls and contracts
Industry recognizes that detection alone is insufficient; supply chain integrity must be ensured.
“Gatekeepers”: Quality control units act as the final barrier against fraud, with stricter specifications beyond normative recommendations. Contracts increasingly include supplier guarantees and destruction clauses for fraudulent batches.
BAPP (Botanical Adulterants Prevention Program): This consortium publishes alerts and laboratory guides to help identify specific adulterants and testing methods. A key SOP promotes destruction of irreparably defective articles (IDA) to prevent resale.
Regulatory bodies: standardization and global surveillance
Authorities strengthen legal frameworks:
Pharmacopoeias and ISO standards define monographs required for compliance. However, these documents also show limitations, as discussed in the previous article “Quality criteria of essential oils: what standards and pharmacopoeias leave in the shadows”.
Rapid Alert System (RASFF): EU system for real-time reporting of unsafe or fraudulent products.
Official investigations and control plans: Agencies such as the ACCC (Australia) and DGCCRF (France) conduct targeted investigations. In 2021, the European Commission launched a coordinated control plan across 23 countries.
Geographical indications (PDO/PGI): Systems such as AOP in France ensure origin and quality through organoleptic and analytical verification by bodies such as INAO.
Consumers and advocacy groups: vigilance and activism
Consumers are no longer passive:
Watchdog groups: Organizations such as CHOICE (Australia) and Cropwatch (UK) test products and expose fraud.
Demand for natural and organic products: Consumer pressure drives reduction of synthetic additives but increases supply chain complexity.
Consumer education: Recommendations include preferring whole spices over powders and selecting reputable suppliers.
Future self-authentication: Emerging interest in portable technologies to verify product authenticity.
Analytical methods for detecting adulteration
Detection relies on multi-level strategies beyond basic physicochemical tests and GC/FID or GC/MS profiling.Isotopic approaches (GC-IRMS, SNIF-RMN) differentiate biosynthetic vs synthetic origins.DNA authentication can complement when genetic markers are preserved.Chemometric and metabolomic approaches (PCA, OPLS-DA) identify low-level adulteration via global signatures.No analytical strategy currently ensures 100% detection of adulteration, requiring integrated and contextual approaches.The best solution remains training and information. Fraudulent practices must not be concealed but exposed, and consumers educated to limit them.
Need training in essential oil authentication? Contact us!
FAQ – Adulteration of plant extracts and essential oils
What is adulteration of a plant extract?
Intentional modification of a botanical raw material for economic gain, altering its chemical, botanical, or isotopic authenticity.
What are the most common forms of adulteration in essential oils?
Dilution with solvents or vegetable oils, addition of synthetic molecules, botanical substitution, or artificial enrichment of analytical markers.
Are GC/MS analyses sufficient to detect adulteration?
No. Classical chromatographic profiles detect only part of adulteration; advanced isotopic or chemometric methods are required.
What is the role of isotopic analysis (IRMS, SNIF-RMN)?
It distinguishes biosynthetic/geographical origin from synthetic molecules through isotopic distribution analysis.
Is DNA analysis always applicable to essential oils?
No. Extraction processes may destroy genetic markers.
Can 100% detection of adulteration be guaranteed?
No analytical strategy currently allows full detection. A multi-technique integrated approach is required.
References
Scientific work on plant extract and essential oil adulteration covers analytical, regulatory, and forensic aspects. The following references constitute a recognized body of literature in botanical authentication and fraud detection.
Prevention Bulletins and Reports (BAPP)
Bejar, E. (2020). Adulteration of English Lavender (Lavandula angustifolia) essential oil. Botanical Adulterants Prevention Bulletin. ABC-AHP-NCNPR Botanical Adulterants Prevention Program.
Botanical Adulterants Prevention Program (BAPP). (2022). Best Practices Standard Operating Procedure (SOP) for the Disposal / Destruction of Irreparably Defective Articles.
Hobbs, C., Upton, R., & Gafner, S. (2024). Cordyceps - Botanical Adulterants Prevention Bulletin. ABC-AHP-NCNPR.
Shulha, O. (2023). English lavender essential oil laboratory guidance document. ABC-AHP-NCNPR Botanical Adulterants Prevention Program.
Scientific Journal Articles
Cordella, C. et al. (2002). Recent Developments in Food Characterization and Adulteration Detection: Technique-Oriented Perspectives. Journal of Agricultural and Food Chemistry, 50, 1751–1764.
Do, T. K. T. et al. (2015). Authenticity of essential oils. TrAC Trends in Analytical Chemistry, 66, 146–157.
Everstine, K., Spink, J., & Kennedy, S. (2013). Economically motivated adulteration (EMA) of food: Common characteristics of EMA incidents. Journal of Food Protection, 76, 723–735.
Gafner, S. et al. (2023). Botanical ingredient forensics: detection of attempts to deceive commonly used analytical methods. Journal of Natural Products, 86(2), 460–472.
Ichim, M. C. (2019). The Global Herbal Products’ Lack of Authenticity: A Survey of DNA Barcoding and Metabarcoding Studies. Frontiers in Pharmacology, 10, 1227.
Velázquez, R. et al. (2023). Spice and Herb Frauds: Types, Incidence, and Detection: The State of the Art. Foods, 12, 3373.
Reference Books
Schmidt, E., & Wanner, J. (2015/2016). Adulteration of Essential Oils. In: Başer, K. H. C., & Buchbauer, G. (Eds.), Handbook of Essential Oils: Science, Technology, and Applications, 2nd ed. CRC Press, pp. 707–746.
