Natural occurrence of Alternaria mycotoxins in wheat and potential of reducing associated risks using magnolol

J Sci Food Agric. 2021 May;101(7):3071-3077. doi: 10.1002/jsfa.10901. Epub 2020 Nov 13.

Abstract

Background: Wheat is one of three major food crops in China. Alternaria species can cause spoilage of wheat with consequent mycotoxin accumulation. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are the most common and frequently studied mycotoxins. There are limited regulations placed on Alternaria mycotoxin concentrations worldwide due to the lack of toxicity data available. More data on the levels of mycotoxin contamination are also needed. It is also important to reduce the risks of Alternaria mycotoxins.

Results: One hundred and thirty-two wheat samples were collected from Hebei Province, China, and analyzed for AOH, AME, and TeA. Tenuazonic acid was found to be the predominant Alternaria mycotoxin, especially in flour samples. Studying Alternaria species that cause black-point disease of wheat indicated that Alternaria alternata and Alternaria tenuissima were the dominant species. Most of the Alternaria strains studied produced more than one mycotoxin and TeA was produced at the highest concentration, which may have resulted in the high level of TeA contamination in the wheat samples. Furthermore, magnolol displayed obvious antifungal and antimycotoxigenic activity against Alternaria. This is the first report on the antimycotoxigenic activity of magnolol against Alternaria species.

Conclusion: The Alternaria mycotoxin contamination levels in wheat and wheat products from Hebei Province, China, were correlated with the toxigenic capacity of the Alternaria strains colonizing the wheat. Considering its safety, magnolol could be developed as a natural fungicide in wheat, or as a natural alternative food preservative based on its strong antifungal and antimycotoxigenic activity against Alternaria strains. © 2020 Society of Chemical Industry.

Keywords: Alternaria; TeA; antifungal; magnolol; mycotoxins; wheat.

MeSH terms

  • Alternaria / drug effects*
  • Alternaria / metabolism
  • Biphenyl Compounds / pharmacology*
  • China
  • Flour / analysis
  • Flour / microbiology
  • Food Contamination / analysis
  • Fungicides, Industrial / pharmacology*
  • Lactones / analysis
  • Lactones / metabolism
  • Lignans / pharmacology*
  • Plant Diseases / microbiology
  • Plant Diseases / prevention & control
  • Tenuazonic Acid / analysis
  • Tenuazonic Acid / metabolism
  • Triticum / chemistry
  • Triticum / microbiology*

Substances

  • Biphenyl Compounds
  • Fungicides, Industrial
  • Lactones
  • Lignans
  • magnolol
  • Tenuazonic Acid
  • alternariol
  • alternariol monomethyl ether

Supplementary concepts

  • Alternaria alternata
  • Alternaria tenuissima