• Media type: E-Article
  • Title: Formation of B- and M-group aflatoxins and precursors by Aspergillus flavus on maize and its implication for food safety
  • Contributor: Schamann, Alexandra; Schmidt-Heydt, Markus; Geisen, Rolf; Kulling, Sabine E.; Soukup, Sebastian T.
  • Published: Springer Science and Business Media LLC, 2022
  • Published in: Mycotoxin Research, 38 (2022) 2, Seite 79-92
  • Language: English
  • DOI: 10.1007/s12550-022-00452-4
  • ISSN: 0178-7888; 1867-1632
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:p>Aflatoxins count to the most toxic known mycotoxins and are a threat to food safety especially in regions with a warm and humid climate. Contaminated food reaches consumers globally due to international trade, leading to stringent regulatory limits of aflatoxins in food. While the formation of aflatoxin (AF) B<jats:sub>1</jats:sub> by the filamentous fungus <jats:italic>Aspergillus flavus</jats:italic> is well investigated, less is known about the formation kinetics of its precursors and further aflatoxins. In this study, autoclaved maize kernels were inoculated with <jats:italic>A. flavus</jats:italic> and incubated at 25 °C for up to 10 days. Aflatoxins and precursors were analyzed by a validated UHPLC-MS method. Additional to AFB<jats:sub>1</jats:sub> and AFB<jats:sub>2</jats:sub>, AFM<jats:sub>1</jats:sub> and AFM<jats:sub>2</jats:sub> were detected, confirming the ability of the formation of M-group aflatoxins on cereals by <jats:italic>A. flavus</jats:italic>. The measured relative levels of AFB<jats:sub>2</jats:sub>, AFM<jats:sub>1</jats:sub>, and AFM<jats:sub>2</jats:sub> on maize compared to the level of AFB<jats:sub>1</jats:sub> (mean of days 5, 7, and 10 of incubation) were 3.3%, 1.5%, and 0.2%, respectively. The occurrence and kinetics of the measured aflatoxins and their precursors sterigmatocystin, O-methylsterigmatocystin, 11-hydroxy-O-methylsterigmatocystin, aspertoxin, and 11-hydroxyaspertoxin (group 1) as well as of dihydrosterigmatocystin and dihydro-O-methylsterigmatocystin (group 2) supported the so far postulated biosynthetic pathway. Remarkable high levels of O-methylsterigmatocystin and aspertoxin (17.4% and 4.9% compared to AFB<jats:sub>1</jats:sub>) were found, raising the question about the toxicological relevance of these intermediates. In conclusion, based on the study results, the monitoring of O-methylsterigmatocystin and aspertoxin as well as M-group aflatoxins in food is recommended.</jats:p>