Occurrence of Alternaria toxins in fibre flax, linseed, and peas grown in organic and conventional farms: Monitoring pilot study

Abstract

Fungi representing Alternaria spp. are ubiquitous pathogens that may under certain conditions cause spoilage of various food crops. Several Alternaria species are known producers of toxic secondary metabolites in some fruits and vegetables, nevertheless, only limited knowledge is available on the occurrence of these mycotoxins in legumes and/or oilseeds used for human nutrition. In the first part of the presented study, the analytical method employing reversed phase high-performance liquid chromatography (HPLC) coupled with fluorescence detection (FLD) was implemented to enable the examination of these food commodities for the presence of altenuene (AE), alternariol (AOH), and alternariol monomethyl ether (AME); the limits of detection were 1, 3 and 2 µg/kg for AE, AOH, and AME, respectively. Altogether 122 flax and 84 pea seed samples grown under organic and/or conventional farming conditions were analysed in the years 2002-2003. AME was detected in 20 flax seed samples; AE and AOH were present in only 2 and 4 samples, respectively. More frequent incidence of Alternaria toxins was recognised in fibre flax seeds as compared to linseed samples. Compared to the crops from the conventional farming, the concentrations of these mycotoxins found in positive organic samples were higher. No Alternaria mycotoxins were detected in the pea samples, probably due to the presence of antifungal compounds in the respective crop.

Keywords

• alternaria
• fungi
• altenuene
• alternariol
• alternariol monomethyl ether
• mycotoxins
• fibre flax seeds
• linseed seeds
• pea seeds