Analysis of pyrrolizidine alkaloids and isomers

Maximum levels for tea, herbs and other food products

May 2023 (update).Since July 2022 new maximum levels for pyrrolizidine alkaloids apply in certain food matrices. They are laid down in Commission Regulation (EU) 2023/915^[1] setting maximum levels for certain contaminants in foodstuffs. Foods that were lawfully placed on the market before July 2022, may continue to be marketed until the end of 2023.

With the regulation the requirements for the analysis of pyrrolizidine alkaloids also increased. The maximum levels refer to the sum of 21 pyrrolizidine alkaloids as well as 14 additional isomers that can analytically overlap with the 21 regulated ones. The sums are formed using the "lower bound" approach.

Maximum levels were established for the following product groups:

tea (including flavoured tea) and herbal tea
food supplements containing herbal ingredients
pollen (products) and pollen-based food supplements
various dried herbs and borage
cumin seeds

The maximum levels refer to the sum of 21 pyrrolizidine alkaloids and N-oxides and 14 additional pyrrolizidine alkaloids and N-oxides which may analytically interfere. The sum is calculated according to the "lower-bound" principle.

Occurrence in plants

An estimated 6000 plant species – which are 3% of all blooming plants – may contain pyrrolizidine alkaloids. The content depends on the plant species and part of the plant, additionally influenced by factors such as soil conditions and climate. The most relevant pyrrolizidine alkaloids producing plants are ragwort (Senecio jacobaea L.) and other members of the daisy family (asteraceae), the forget-me-not or borage family (boraginaceae) and the family of pulses (fabaceae or leguminosae).

Occurrence in food and feed

Pyrrolizidine alkaloids usually contaminate food and feed via PA-containing weeds. Lettuce, leafy vegetables, herbs, spices, tea, honey and pollen-based products, as well as borage oil, have long been known as potentially affected food groups. The German Federal Institute for Risk Assessment (BfR) has also reported the occurrence of pyrrolizidine alkaloids in pseudocereals in 2014. Pyrrolizidine alkaloids can also pose a serious problem in animal feed, especially in hay and silage, as the characteristic inherent odour of the specific plants is no longer noticeable for animals.

Toxicology

Pyrrolizidine alkaloids can cause liver damage and show genotoxic and carcinogenic effects in animal experiments with no safe threshold value being derived. In June 2020, the German Federal Institute for Risk Assessment published an updated Risk Assessment on pyrrolizidine alkaloids in foodstuffs in its statement 026/2020 (in German). New data from the years 2015-2019 show that the intake of pyrrolizidine alkaloids e.g. from honey, milk, spinach and especially tea and herbal tea has decreased in recent years. For food groups also relevant for PA intakes such as herbs, spices and food supplements, no conclusive statement could be made due to the lack of sufficient data. However, according to the BfR, there is reason to recommend continuing efforts to reduce the levels of pyrrolizidine alkaloids in food groups such as herbs and spices by improving cultivation, harvesting and cleaning methods.

Analysis of pyrrolizidine alkaloids and isomers

Our experts from the Competence Center for Mycotoxins and Plant Toxins within the Eurofins Food & Feed Testing laboratory network in Germany have many years of experience with LC-MS/MS analysis of pyrrolizidine alkaloids in all relevant food and feed matrices. Our participation in (inter)national committees has enabled us for years to continuously improve and adapt the analysis and evaluation of pyrrolizidine alkaloids to the latest legal/scientific status quo. Our method adjustments allow the complex summations of the 21 plus 14 pyrrolizidine alkaloids or N-oxides according to the new regulation. In addition to the 21+14 pyrrolizidine alkaloids, our analysis portfolio also includes testing under GMP conditions for selected matrices.

Please contact us

Do you have questions about the analysis of pyrrolizidine alkaloids? Please contact your personal account manager or our experts Carina Kellner or Sandra Kobüssen.

Relevant Regulations

[1] Commission Regulation (EU) 2023/915 (Contaminants-Regulation)