Month: June 2025

Détection de falsifications des baies de poivre noir Piper nigrum (L.) par d’autres espèces végétales avec BotaniCERT

Detection of adulteration in black pepper berries Piper nigrum L. with other plant species

Written by Loïc Loffredo on June 17, 2025. Posted in blog.

Black pepper is one of the most widely used spices in households. It is often purchased in whole berry form and ground before use. In the agri-food sector or bulk plant trade, pepper is sold as whole berries, ground powder, or dry extracts.

Active compounds in black pepper

In dry extracts, the focus is on extracting piperine, an alkylamide and the major compound in black pepper. Piperine is responsible for the pepper’s pungent taste and is also linked to its beneficial properties, including antimicrobial and anti-inflammatory effects.

Black pepper adulteration

As with all processed products, the risk of adulteration is much greater. In the case of black pepper, there is a long history of adulteration that continues today: the use of olive pits. While this may seem rather crude, the fact that if it is still being used it is because the quality controls don’t detect it.

Indeed, as with all cases of adulteration by mixing with a contaminant, if the testing only looks for the presence of expected markers (in this case, piperine) the addition of the adulterant can never be detected. The study presented here outlines how to overcome this type of problem.

Standard control of a dry black pepper extract

As with all plants containing a high concentration of a single substance, quality control is usually based solely on the presence of this predominant molecule. However, such testing is insufficient. Indeed, if the analysis focuses only on the correct presence of the predominant compound (namely piperine) most cases of fraud, errors, or contamination will go undetected.

HPTLC profiles (366 nm on the left, white light on the right) of pepper samples
1: Piperine standard
2: Customer dry extract of *Piper nigrum* L.
3: Reference sample of *Piper nigrum* L. berries

Cases that can be detected	Cases that cannot be detected
– Absence of black pepper and presence of another plant species that does not contain piperine (absence of piperine) – Extreme dilution of the extract (absence of piperine) – Presence of another species whose molecules will be detected by this analysis	– Unintentional presence of another species as a contaminant – Confusion with a closely related species – Intentional presence of another species as an adulterant – Enrichment with synthetic piperine

It is clear that the vast majority of frauds and errors found on the market fall into the cases that cannot be detected by methods relying solely on the presence of a single compound. Detecting adulteration with olive pits is therefore impossible using such an approach. So, what is the point of carrying out this type of test? The value is purely regulatory, because from a risk analysis perspective, this test does not reduce the potential risks associated with this raw material.

Detection of fraudulent compounds in samples

To detect adulteration of black pepper with olive pits, it is necessary to look for markers of both black pepper and olive pits. Using a more comprehensive compositional analysis, as shown in the chromatograms below, unexpected compounds in a black pepper sample can be quickly identified, revealing the presence of a mixture of black pepper and olive pits.

1: UHPLC-DAD profile (190–600 nm) of a commercial black pepper sample
2: UHPLC-DAD profile (190–600 nm) of a reference sample of Olea europaea L. pits
3: Overlay of the two UHPLC-DAD profiles above: commercial black pepper (green) and olive pits (red)

An untargeted analysis to identify all types of black pepper adulteration

Using the characteristic compounds of olive pits is therefore not a solution. Indeed, if we focus once again on a single marker, we can only conclude that the specific target marker is present or not. In this case, it only confirms whether olive pits are absent from the black pepper sample. But what about other potential adulterations?

The solution is to perform an untargeted analysis, as this would reveal unexpected markers and therefore, all types of adulteration.

Performing an inadequate inspection (such as a simple check for the presence of piperine) may prove too limited, especially considering that frauds are often subtle and difficult to detect.

How can you ensure the quality of your black pepper samples?

By confirming the presence of black pepper, the absence of other species that could be used as adulterants, and by measuring piperine as the target marker.

Contact us to know more

Detection of adulteration of Rhodiola rosea L. with other plant species

Written by Loïc Loffredo on June 16, 2025. Posted in blog.

Formerly known by its more familiar name Rhodiola rosea L., Rhodiola is also called “golden root.” It grows in cold, mountainous regions. In Scandinavian countries, Rhodiola root has long been used to protect against and its the particularly stressful effects.

Properties and benefits of Rhodiola rosea L.

It is an antioxidant adaptogenic plant that helps the body adapt and protect cells during periods of physical and emotional stress. Rhodiola root extract helps reduce stress related fatigue or intense mental activity, and contributes to normal blood circulation. It is also linked to performance and intellectual responsiveness as well as optimal cognitive activity. Rhodiola root extract helps stimulate the nervous system and has beneficial effects on stress-induced fatigue and headaches, as well as on the cardiovascular system. It contributes to protecting the body from stress and helps maintain normal blood pressure.

Chemical activity of Rhodiola rosea L.

These effects are linked to the presence of specific substances such as rosavins (including rosavin, rosarin, rosine, and rosiridin), as well as salidroside and tyrosol. Dry extracts are also titrated for these molecules to ensure optimal quality. However, due to high demand, this plant is becoming increasingly rare and will become more difficult to source in the coming years. As a result, fraud is commonplace in an attempt to meet market demand.

Figure 1: Chemical structure of the major compounds of *Sedum roseum* (L.) Scop.

How to detect the adulteration of Rhodiola with other plant species

First of all, it is known that other species can be used in place of Sedum roseum, particularly Rhodiola crenulata (Hook.f. & Thomson) H.Ohba, which is known as the main adulterant. The absence of a monograph in pharmacopoeias means that internal methods must be used, and knowing the key features that differentiate Sedum roseum from other closely or distantly related plant species is crucial.

Examples of Rhodiola adulteration based on customer sample analyses

Each species has a distinct chemical profile. It is therefore essential to know what to expect from a typical profile of Sedum roseum (L.) Scop. root. In the various chemical profiles analysed, at BotaniCERT we have concluded that there are few compositional differences based on geographic origin (see Figure 2). In a campaign involving 74 commercial Rhodiola samples, 27 were identified as non-compliant with regard to the target species, representing 36% non-compliance. Among the various potential adulterants, Rhodiola crenulata (Hook.f. & Thomson) H.Ohba was the most frequently used in place of the intended species.

Figure 2: HPLC-UV overlay of 6 samples of *Sedum roseum* (L.) Scop.

R. crenulata can be distinguished by the absence of rosavin derivatives, although it still contains high levels of salidroside and tyrosol. This species has significantly higher tannin content than S. roseum, particularly numerous gallate derivatives / esters of gallic acid (see Figure 3, compounds highlighted in blue). However, other species also contain rosavin derivatives, albeit in different proportions. Therefore, an analysis that focuses solely on these compounds is insufficient to reliably determine the plant species used to produce the extract.

Figure 3: Overlay of commercial sample and authentified reference of *Sedum roseum* (L.) Scop. roots

Proving the authenticity of Rhodiola through BotaniCERT testing

Rhodiola is a high-risk plant due to its complex sourcing and the numerous cases of fraud found on the market. Currently, the roots of Rhodiola crenulata (Hook.f. & Thomson) H.Ohba are frequently used to adulterate the target species, but fraud is evolving, and new types of adulteration will inevitably emerge. To effectively mitigate potential fraud, it is best to rely on the most comprehensive chemical profile possible, rather than on a single group of markers, which is often too restrictive to draw relevant conclusions.

Carrying out appropriate testing is essential for your plant-based products, particularly for extracts that are frequently adulterated.

How can you ensure the quality of your Rhodiola samples?
By performing an authentication adapted to dry extracts, and by confirming the presence of the target species, the absence of other plant species in the mixture, the absence of enrichment, and verifying the quantities of claimed active compounds.