Fumonisin Determination in Tunisian Foods and Feeds. ELISA and HPLC Methods Comparison

A survey for fumonisins B1 and B2 (FBI and FB2, respectively) was performed on 180 samples of high-consumption food commodities and 15 feed samples randomly collected from various regions of Tunisia. The determination of fumonisin level was performed by an in-house validated high-performance liquid chromatography and an enzyme-linked immunosorbent assay (ELISA) methods. Detection limit by ELISA for fumonisins sum was 25 mu g/kg, and those by HPLC were 50 mu g/kg for FBI and 70 mu g/kg for FB2. Recoveries of fumonisins spiked at 130 mu g/kg ranged from 68.5 to 75.6% by ELISA, whereas those by HPLC for FBI at 400 mu g/kg and for FB2 at 300 mu g/kg varied from 75.2 to 90.5%. Naturally occurring fumonisins were found in 10.5% of food samples with levels ranging from 70 to 2130 mu g/kg. All contaminated samples contained FBI, and 31.5% of them contained FB2. In addition, the most contaminated commodities were corn foods and sorghum, whereas no fumonisin contamination was found in any nut or rice samples. For analyzed feed samples, fumonisins were detected in 86.6% of them with concentrations ranging from 50 to 2800 mu g/kg. In addition, the performance of analytical methods was investigated in a comparison between ELISA and HPLC results for samples analyzed by both methods.