Pyrrolizidine Alkaloids in Food on the Italian Market

Abstract

Pyrrolizidine alkaloids (PAs) are secondary metabolites produced by over 6000 plant species worldwide. PAs enter the food chain through accidental co-harvesting of PA-containing weeds and through soil transfer from the living plant to surrounding acceptor plants. In animal studies, 1,2-unsaturated PAs have proven to be genotoxic carcinogens. According to the scientific opinion expressed by the 2017 EFSA, the foods with the highest levels of PA contamination were honey, tea, herbal infusions, and food supplements. Following the EFSA’s recommendations, data on the presence of PAs in relevant food were monitored and collected. On 1 July 2022, the Commission Regulation (EU) 2020/2040 came into force, repealed by Commission Regulation (EU) 2023/915, setting maximum levels for the sum of pyrrolizidine alkaloids in certain food. A total of 602 food samples were collected from the Italian market between 2019 and 2022 and were classified as honey, pollen, dried tea, dried herbal infusions, dried herbs, and fresh borage leaves. The food samples were analyzed for their PA content via an in-house LC-MS/MS method that can detect PAs according to Regulation 2023/915. Overall, 42% of the analyzed samples were PA-contaminated, 14% exceeded the EU limits, and the items most frequently contaminated included dried herbs and tea. In conclusion, the number of food items containing considerable amounts of PAs may cause concern because they may contribute to human exposure, especially considering vulnerable populations—most importantly, children and pregnant women.

Recent food alerts and analytical advances related to the contamination of tropane and pyrrolizidine alkaloids in food

“…Atropine was detected in 12 samples, whereas scopolamine was detected only in one, with concentrations of 2.7-3.4 μg/kg. In the case of PAs, they have been determined in borage leaves using solvent extraction with 0.05 M H 2 SO 4 followed by SPE with MCX cartridges (Peloso et al, 2023). As expected, all borage samples presented PAs (mean concentration 530.8 μg/kg), and only in one the content (3410 μg/kg) exceeded the maximum limit (750 μg/kg).…”

“…This miniaturization has allowed improving the QuEChERS strategy, leading to a more sustainable and green method. Nonetheless, despite the technique employed, PA levels exceeding the maximum limit established by regulation for aromatic herbs have been detected in these works, namely, in oregano, marjoram, cumin, thyme, parsley, savory, dill and chive (Kaltner et al, 2020a;Izcara et al, 2020;Kaczyński and Łozowicka, 2020;Izcara et al, 2022;Peloso et al, 2023).…”

“…In fact, oregano is one of the most adulterated herbs (Maquet et al, 2021). Due to the high frequency of contamination of these products with TAs and PAs, different authors have developed several analytical procedures for the determination of these alkaloids in aromatic herbs and spices (Kaltner et al, 2020a;Izcara et al, 2020;Kaczyński and Łozowicka, 2020;González-Gómez et al, 2022b;Izcara et al, 2022;González-Gómez et al, 2023a;Peloso et al, 2023). For instance, in the case of TAs, extraction has been performed with acidic water solution (1.1.% HCl) followed by solid-phase extraction (SPE) (González-Gómez et al, 2022b;González-Gómez et al, 2023a).…”

“…The results obtained in these works revealed coriander, basil, fennel and cloves as the products with the highest concentrations of TAs (González-Gómez et al, 2022b;González-Gómez et al, 2023a). For PAs, acidic solvent extraction with 0.05 M H 2 SO 4 followed by SPE with cation-exchange sorbents (e.g., SCX and MCX) has been used as sample treatment (Kaltner et al, 2020a;Peloso et al, 2023). However, besides SPE, other techniques such as QuEChERS have successfully been applied to the analysis of PAs in herbs and spices (Izcara et al, 2020;Kaczyński and Łozowicka, 2020;Izcara et al, 2022).…”

“…On the one hand, some authors have determined the presence of these alkaloids in the dry product (Kwon et al, 2021;Han et al, 2022a;Han et al, 2022b;Jansons et al, 2022;León et al, 2022;Luo et al, 2022;Jiao et al, 2023b;Gumus, 2023;Mateus et al, 2023;Peloso et al, 2023). For PAs, many authors have performed and acidic solvent extraction with H 2 SO 4 (0.05-0.1 M) followed by SPE purification with MCX cartridges or dispersive clean-up with GCB, PSA and C18 sorbents (Kwon et al, 2021;Han et al, 2022a;Han et al, 2022b;Jiao et al, 2023b;Peloso et al, 2023). Likewise, QuEChERS has been used for both PAs and TAs (Han et al, 2022b;Jansons et al, 2022;León et al, 2022;Jiao et al, 2023b;Mateus et al, 2023).…”