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1,2-Unsaturated pyrrolizidine alkaloids (PA), their corresponding N-oxides (PANO), and tropane alkaloids (TA) are toxic secondary plant metabolites. Their possible transfer into the milk of dairy cows has been studied in feeding trials; however, only few data on the occurrence of these toxins in milk are available. In this study, the development of a sensitive analytical approach for the simultaneous detection and quantification of a broad range of 54 PA/PANO as well as of the TA atropine and scopolamine in milk of dairy cows is presented. The method optimisation focused on sensitivity and separation of PA/PANO isomers. Milk samples were extracted using liquid–liquid extraction with aqueous formic acid and n-hexane, followed by a cation-exchange solid-phase extraction for purification. Reversed phase liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis was performed using alkaline solvent conditions. Validation proved low limits of detection and quantification of 0.005 to 0.054 µg/L and of 0.009 to 0.123 µg/L, respectively. For 51 of the 54 tested PA/PANO and both TA, the recovery rates ranged from 64 to 127% with repeatability (RSDr) values below 15% at concentration levels of 0.05 and 0.50 µg/L and below 8% at a concentration level of 3.00 µg/L. Only three PANO did not match the validation criteria and were therefore regarded as semiquantitative. The final method was applied to 15 milk samples obtained from milk vending stations at farms and from local marketers in Bavaria, Germany. In three of the milk samples, traces of PA were detected. [ABSTRACT FROM AUTHOR]

Straw is the main by-product of grain production, used as bedding material and animal feed. If produced or stored under adverse hygienic conditions, straw is prone to the growth of filamentous fungi. Some of them, e.g. Aspergillus, Fusarium and Stachybotrys spp. are well-known mycotoxin producers. Since studies on mycotoxins in straw are scarce, 192 straw samples (wheat n = 80; barley n = 79; triticale n = 12; oat n = 11; rye n = 12) were collected across Germany within the German official feed surveillance and screened for the presence of 21 mycotoxins. The following mycotoxins (positive samples for at least one mycotoxin n = 184) were detected: zearalenone (n = 86, 6.0–785 μg/kg), nivalenol (n = 51, 30–2,600 μg/kg), deoxynivalenol (n = 156, 20–24,000 μg/kg), 15-acetyl-deoxynivalenol (n = 34, 20–2,400 μg/kg), 3-acetyl-deoxynivalenol (n = 16, 40–340 μg/kg), scirpentriol (n = 14, 40–680 μg/kg), T-2 toxin (n = 67, 10–250 μg/kg), HT-2 toxin (n = 92, 20–800 μg/kg), T-2 tetraol (n = 13, 70–480 μg/kg). 15-monoacetoxyscirpenol (30 μg/kg) and T-2 triol (60 μg/kg) were only detected in one barley sample. Macrocyclic trichothecenes (satratoxin G, F, roridin E, and verrucarin J) were also found in only one barley sample (quantified as roridin A equivalent: total 183 μg/kg). The occurrence of stachybotrylactam was monitored for the first time in four samples (n = 4, 0.96–7.4 μg/kg). Fusarenon-X, 4,15-diacetoxyscirpenol, neosolaniol, satratoxin H and roridin-L2 were not detectable in the samples. The results indicate a non-negligible contribution of straw to oral and possibly inhalation exposure to mycotoxins of animals or humans handling contaminated straw. [ABSTRACT FROM AUTHOR]

The Bacillus (B.) cereus group consists of nine recognized species which are present worldwide. B. cereus play an important role in food-borne diseases by producing different toxins. Yet, only a small percentage of B. cereus strains are able to produce the heat stable cereulide, the causative agent of emetic food poisoning. To minimize the entry of emetic B. cereus into the food chain, food business operators are dependent on efficient and reliable methods enabling the differentiation between emetic and non-emetic strains. Currently, only time-consuming cell bioassays, molecular methods and tandem mass spectrometry are available for this purpose. Thus, the aim of the present study was to establish a fast and reliable method for the differentiation between emetic/non-emetic strains by MALDI-TOF MS. Selected strains/isolates of the B. cereus group as well as other Bacillus spp. (total n = 121) were cultured on sheep blood agar for 48 h before analysis. Subsequently, the cultures were directly analyzed by MALDI-TOF MS without prior extraction steps. The samples were measured in the mass range of m/z 800–1800 Da. Using ClinProTools 3.0 statistical software and Flex analysis software (Bruker Daltonics GmbH, Bremen, Germany), a differentiation between emetic/non-emetic isolates was possible with a rate of correct identification of 99.1% by means of the evaluation of two specific biomarkers (m/z 1171 and 1187 Da). • Fast/reliable MALDI-TOF MS method for differentiation of emetic/non-emetic B. cereus. • Directly analyzed by MALDI-TOF MS without prior extraction steps (direct smear). • Differentiation of emetic/non-emetic B. cereus with 99.1% correct identification. • Biomarkers for differentiation of emetic/non-emetic B. cereus (m/z 1171 and 1187 Da). [ABSTRACT FROM AUTHOR]

Pyrrolizidine alkaloids (PA) and PA N-oxides (PANO) are secondary plant metabolites exhibiting genotoxic and carcinogenic properties. Apart from the roots and leaves, PA/PANO are particularly present in pollen and nectar. Therefore, the spread of Jacobaea vulgaris in certain regions of northern Germany has an impact on the safety of honey produced in that region. In this study, raw honey samples (n = 437) were collected from usually three individual beehives per site (n = 73) in the district of Ostholstein and analyzed for 25 PA/PANO. The results reveal mean levels of 8.4, 1.5, and 72.6 µg/kg and maximum levels of 111, 59.4, and 3313 µg/kg, depending on the season (summer 2015 and spring/summer 2016, respectively). As far as individual data are concerned, sites near areas with J. vulgaris growth did not necessarily result in high PA/PANO values. Furthermore, intra-site investigations revealed remarkable differences in PA/PANO levels of raw honey collected by different bee colonies at the same site. Consumption of these regionally produced honeys entails an increased exposure to PA/PANO, especially in children and high consumers. Margin of exposure values of <10,000 and an exceedance of the health-based guidance value highlight that regionally produced and marketed honey must be considered with care for a proper risk assessment and risk management. [ABSTRACT FROM AUTHOR]

1,2-Dehydro-pyrrolizidine alkaloids (PA), their corresponding N -oxides (PANO) and tropane alkaloids (TA), are toxic plant metabolites. If plant material, containing these toxins, is present in the feed of dairy cows these toxins can be transferred into milk. Here, milk was sampled directly from dairy farms in the German federal states of Bavaria and Schleswig-Holstein in 2020-2022 in order to investigate a possible contamination of milk at the production stage. In total, 228 milk samples were analysed for 54 PA/PANO and two TA by a sensitive LC-ESI-MS/MS method. In addition, a subset of milk samples ( n  = 85) was independently analysed for TA by a cooperating laboratory for verification. PA/PANO were found in 26 samples (11%) with a low median sum content of the contaminated samples of 0.024 µg/L. The highest level of contamination was 5.6 µg/L. Senecionine-, lycopsamine- and heliotrine-type PA/PANO were detected. In four samples (1.8%), atropine was determined up to 0.066 µg/L. The toxin levels in the milk samples hardly contributed to the total daily exposure. These data are first-time results on contamination rates and levels occurring in milk from individual dairy farms, based on a large sample number.

Brewer's yeasts are rich in vitamins of the B-group and contain other nutritive factors; therefore, they are recommended as valuable food supplements for people with special dietary requirements like pregnant women, children, and adolescents, or for people with high physical activity. Additionally, certain strains of brewer's yeast are known to be capable of adsorbing xenobiotics such as mycotoxins. Because of that, these yeasts are regarded as having positive effects in food, beverage, and feed technology. Their potential to bind mycotoxins such as ochratoxin A (OTA), however, can subsequently lead to a contamination of such brewer's yeasts used as food supplements. In the present study, we analyzed 46 samples of brewer's yeasts for the occurrence of OTA by HPLC with fluorescence detector (HPLC-FLD) and for confirmatory measurements by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Nearly 90% of the samples were contaminated with OTA, the levels ranging from the limit of detection (LOD, 0.01 μg/kg) to 4.2 μg/kg. The mean and median levels of contamination were 0.49 and 0.27 μg/kg, respectively. Based on these results, the additional weekly OTA exposure by regularly consuming such supplements was assessed. Depending on different subpopulations (adults, children) and levels of contamination used for calculation, the additional OTA intake via brewer's yeast products ranged from 9.3% (mean case) to 114% (worst case) of the published mean weekly OTA intake in Germany (adults 279.3 ng, children 195.3 ng). At present, maximum levels for OTA in nutritional supplements like brewer's yeast do not exist. Based on our results, however, it is recommended that producers of these dietary supplements should include mycotoxin analyses in ongoing and future self-monitoring programs and in product quality checks.