Comparison of methods and optimization of the analysis of fumonisins B1 and B2 in masa flour, an alkaline cooked corn product

Annalisa de Girolamo (1) , Michelangelo Pascale (2) , Angelo Visconti (2)

1 ISPA - Istituto Scienze delle Produzioni Alimentari
2 ISPA - Institute of Sciences of Food Production

A comparison study of different extraction and clean up procedures for the liquid chromatographic analysis of fumonisins B1 (FB1) and B2 (FB2) in corn masa flour has been performed. They included extraction with (heated or at room temperature) acidic conditions or EDTA containing solvents, and clean up by immunoaffinity or C18 solid phase extraction columns. Thereafter an analytical method has been optimized using extraction with an acidic mixture of methanol-acetonitrile-citrate/phosphate buffer, clean-up through immunoaffinity column and fumonisins determination by high performance liquid chromatography with automated pre-column derivatization with o-phthaldialdehyde reagent. Recovery experiments performed on yellow, white and blue masa flours at spiking levels of 400, 800 and 1200 µg kg-1 FB1, and 100, 200 and 300 µg kg-1 FB2 gave overall mean recoveries of 99% (± 6%) for FB1 and 88% (± 6%) for FB2. Good recoveries (higher than 90% for both FB1 and FB2) were also obtained with corn tortilla chips. The limit of quantification of the method (signal to noise ratio of 6) was 15 µg kg-1 for FB1 and 10 µg kg-1 for FB2. The method was tested on different commercial corn masa flours as well as on white and yellow corn tortilla chips, showing fumonisins contamination levels (FB1 + FB2) up to 1800 µg kg-1 (FB1 + FB2) in masa flour and 960 µg kg-1 in tortilla chips. Over 30% of masa flours originated from Mexico exceeded the EU maximum permitted level.

Mots clés: Life Sciences

Annalisa de Girolamo, Michelangelo Pascale, Angelo Visconti. Comparison of methods and optimization of the analysis of fumonisins B1 and B2 in masa flour, an alkaline cooked corn product. Food Additives and Contaminants, 2011, pp.1. ⟨10.1080/19440049.2011.555846⟩. ⟨hal-00677971⟩