TY - JOUR A1 - Siegel, David A1 - Merkel, Stefan A1 - Bremser, Wolfram A1 - Koch, Matthias A1 - Nehls, Irene T1 - Degradation kinetics of the Alternaria mycotoxin tenuazonic acid in aqueous solutions N2 - The degradation kinetics of the Alternaria mycotoxin tenuazonic acid (l-TA) in aqueous buffer were studied over a period of 4 months at different pH levels (3.5 and 7.0) and temperatures (4, 25 and 40°C). l-TA and its degradation products were quantified by newly developed high-performance liquid chromatography methods with UV or electrospray multistage mass spectrometry detection. At pH 3.5, significant degradation occurred at 25 and 40°C, the respective l-TA half-lives being 73.8±0.4 and 14.0±0.1 days. Two degradation processes, epimerization and hydrolysis, were evaluated kinetically. The hydrolytically formed iso-deacetyl TA (iso-DTA, epimeric mixture) was found to be the stable end product of l-TA degradation under the conditions of this study. This indicates that iso-DTA as well as the l-TA epimer u-TA are formed in aqueous beverage matrices. KW - Tenuazonic acid KW - Alternaria KW - Epimerization KW - Degradation KW - Kinetics PY - 2010 DO - https://doi.org/10.1007/s00216-009-3288-5 SN - 1618-2642 SN - 1618-2650 VL - 397 IS - 2 SP - 453 EP - 462 PB - Springer CY - Berlin AN - OPUS4-21373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Koch, Matthias A1 - Siegel, David A1 - Merkel, Stefan A1 - Maul, Ronald A1 - Nehls, Irene T1 - Determination of mycotoxins in foods: current state of analytical methods and limitations N2 - Mycotoxins are natural contaminants produced by a range of fungal species. Their common occurrence in food and feed poses a threat to the health of humans and animals. This threat is caused either by the direct contamination of agricultural commodities or by a "carry-over" of mycotoxins and their metabolites into animal tissues, milk, and eggs after feeding of contaminated hay or corn. As a consequence of their diverse chemical structures and varying physical properties, mycotoxins exhibit a wide range of biological effects. Individual mycotoxins can be genotoxic, mutagenic, carcinogenic, teratogenic, and oestrogenic. To protect consumer health and to reduce economic losses, surveillance and control of mycotoxins in food and feed has become a major objective for producers, regulatory authorities and researchers worldwide. However, the variety of chemical structures makes it impossible to use one single technique for mycotoxin analysis. Hence, a vast number of analytical methods has been developed and validated. The heterogeneity of food matrices combined with the demand for a fast, simultaneous and accurate determination of multiple mycotoxins creates enormous challenges for routine analysis. The most crucial issues will be discussed in this review. These are (1) the collection of representative samples, (2) the performance of classical and emerging analytical methods based on chromatographic or immunochemical techniques, (3) the validation of official methods for enforcement, and (4) the limitations and future prospects of the current methods. KW - Mycotoxins and fungal metabolites KW - Food KW - Rapid and validated methods KW - Regulations KW - Sampling KW - Multi-mycotoxin determination PY - 2010 DO - https://doi.org/10.1007/s00253-010-2535-1 SN - 0175-7598 VL - 86 IS - 6 SP - 1595 EP - 1612 PB - Springer CY - Berlin AN - OPUS4-21184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Troyanov, S. A1 - Noack, J. A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Alternariol N2 - In the title compound (systematic name: 3,7,9-trihydroxy-1-methyl-6H-benzo[c]chromen-6-one), C14H10O5, the methyl group is shifted out of the molecular plane due to a steric collision, thus causing a slight twist of the benzene rings. The molecular structure is stabilized by an intramolecular O-H...O hydrogen bond, generating an S(6) ring. In the crystal, molecules are connected by intermolecular O-H...O hydrogen bonds into a three-dimensional network. KW - Alternariol KW - Kristallstruktur PY - 2010 DO - https://doi.org/10.1107/S1600536810017502 SN - 1600-5368 VL - 66 IS - 6 SP - o1366 PB - Munksgaard CY - Copenhagen AN - OPUS4-21400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Babuscio, T. T1 - Mycotoxin management in the European cereal trading sector N2 - On the world scale, the European Union has established the most comprehensive regulations for mycotoxins in food and feed. These regulations, which areinter alia expressed in the form of maximum levels, largely affect cereal traders. To ensure the safety of their products and compliance with EU legislation traders are required to quantify the mycotoxin levels in their lots. However, while the analytical approaches of research and enforcement are well known and frequently reviewed in the scientific and legal literature, little detailed information is available on the mycotoxin management concepts of trade. The present article is intended to close this gap. On the basis of the results of two surveys conducted amongst European cereal traders in the years 2007 and 2009, three key issues in commercial mycotoxin management are outlined and discussed in the context of the current scientific literature. These are: the issue of sampling, the availability and performance of suitable analytical methods as well as issues evolving from variations between regulatory and contractual maximum levels. KW - Mycotoxins KW - Cereals KW - Trading KW - Analysis KW - Food safety PY - 2011 DO - https://doi.org/10.1016/j.foodcont.2011.02.022 SN - 0956-7135 VL - 22 IS - 8 SP - 1145 EP - 1153 PB - Elsevier CY - Amsterdam AN - OPUS4-23526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Bremser, Wolfram A1 - Köppen, Robert A1 - Krüger, Rita A1 - Rasenko, Tatjana A1 - Siegel, David A1 - Nehls, Irene T1 - Certification of reference materials for ochratoxin A analysis in coffee and wine N2 - Mycotoxins are important non-anthropogenic food and feed contaminants, which can be present on almost every agricultural commodity. Effective consumer protection therefore essentially depends on food surveillance by reliable quantitative analysis enabled by appropriate quality control. Certified (matrix) reference materials (CRMs) are versatile tools to support Quality assurance. However, in the case of ochratoxin A (OTA), a hepato- and nephrotoxic mycotoxin, which is regulated in various foods, there is a lack of suitable CRMs. This lack has now been overcome by the development of two European Reference Materials (ERM®) for the Determination of OTA in roasted coffee (ERM®-BD475) and red wine (ERM®-BD476). This article discusses the material preparation process as well as the results of homogeneity and stability testing. Furthermore, the results of the inhouse certification studies carried out at BAM Federal Institute for Materials Research and Testing are presented and discussed. Interlaboratory comparison studies involving selected expert laboratories with documented Expertise in the field of mycotoxin analysis were conducted to confirm the certified values determined by BAM. The certified ochratoxin A values and their corresponding expanded uncertainties (k = 2) were assigned in full compliance with the requirements of ISO Guide 35 and are as follows: (6.0 ± 0.6) µg kg-1 for roasted coffee, ERM®-BD475, and (0.52 ± 0.11) µg L-1 for red wine, ERM®-BD476. KW - OTA KW - Coffee KW - Wine KW - Food safety and quality KW - European reference materials KW - CRM PY - 2011 DO - https://doi.org/10.1007/s00769-011-0783-0 SN - 0949-1775 SN - 1432-0517 VL - 16 SP - 429 EP - 437 PB - Springer CY - Berlin AN - OPUS4-24235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, M.E.H. A1 - Steier, I. A1 - Köppen, Robert A1 - Proske, Matthias A1 - Korn, U. A1 - Koch, Matthias A1 - Siegel, David T1 - Cocultivation of phytopathogenic Fusarium and Alternaria strains affects fungal growth and mycotoxin production N2 - Aims: A laboratory study was conducted to evaluate the influence of cocultivation of toxigenic Fusarium (F.) and Alternaria (A.) fungi with respect to growth and mycotoxin production. Methods and Results: Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were simultaneously or consecutively co-incubated on wheat kernels in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (DON, NIV and ZON) and three Alternaria toxins (AOH, AME and ALT) were analysed by a newly developed HPLC/MS/MS method. In simultaneous cocultures, the fungal biomass was enhanced up to 460% compared with individual cultures; Alternaria toxins were considerably depressed down to <5%. Combining At18 and At220 with Fg23 inhibited the toxin production of both fungal partners. In contrast, Fc13 increased its DON and ZON production in competitive interaction with both A. strains. Conclusions: The interfungal competitive effects aid the understanding of the processes of competition of both fungi in natural environments and the involvement of mycotoxins as antifungal factors. Significance and Impact of Study: Cocultivation significantly affects fungal growth and mycotoxin production of phytopathogenic Alternaria and Fusarium strains. The impact of mycotoxins on the interfungal competition is highlighted. KW - Alternaria KW - Cocultivation KW - Ergosterol KW - Fusarium KW - Interfungal competition KW - Multimycotoxin analysis PY - 2012 DO - https://doi.org/10.1111/j.1365-2672.2012.05388.x SN - 1364-5072 VL - 113 IS - 4 SP - 874 EP - 887 PB - Wiley-Blackwell CY - Malden, Mass., USA AN - OPUS4-26932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, M.E.H. A1 - Urban, K. A1 - Köppen, Robert A1 - Siegel, David A1 - Korn, U. A1 - Koch, Matthias T1 - Mycotoxins as antagonistic or supporting agents in the interaction between phytopathogenic Fusarium and Alternaria fungi N2 - The role of mycotoxins in the microbial competition in an ecosystem or on the same host plant is still unclear. Therefore, a laboratory study was conducted to evaluate the influence of mycotoxins on growth and mycotoxin production of Fusarium and Alternaria fungi. Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were incubated on wheat kernels supplemented with alternariol (AOH), tetramic acid derivates (TeA), deoxynivalenol (DON) and zearalenone (ZEA) in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (DON, nivalenol and ZEA) and three Alternaria toxins (AOH, alternariol methyl ether (AME) and altenuene) were analysed by HPLC-MS/MS. If Alternaria strains grew in wheat kernels spiked with Fusarium mycotoxins, their growth rates were moderately increased, their AOH and AME production was enhanced and they were simultaneously capable of degrading the Fusarium mycotoxins DON and ZEA. In contrast, both Fusarium strains behaved quite differently. The growth rate of Fc13 was not distinctly influenced, while Fg23 increased its growth in wheat kernels spiked with AOH. TeA depressed the ergosterol content in Fc13 as well as in Fg23. The DON production of Fc13 was slightly depressed, whereas the ZEA production was significantly increased. In contrast, Fg23 restricted its ZEA production. Both Fusarium strains were not capable of degrading the Alternaria mycotoxin AOH. Mycotoxins might play an important role in the interfungal competitive processes. They influence growth rates and mycotoxin production of the antagonistic combatants. The observed effects between phytopathogenic Alternaria and Fusarium strains and their mycotoxins aid the understanding of the complexity of microbial competitive behaviour in natural environments. KW - Phytopathogen KW - Trichothecenes KW - Alternaria mycotoxins KW - Multi-mycotoxin analysis KW - Inter-fungal competition PY - 2015 DO - https://doi.org/10.3920/WMJ2014.1747 SN - 1875-0710 SN - 1875-0796 VL - 8 IS - 3 SP - 311 EP - 321 PB - Wageningen Academic Publishers CY - Wageningen AN - OPUS4-32849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -