Distribution of fumonisins and aflatoxins in corn fractions during industrial cornflake processing

Abstract

The aim of this study was to investigate the distribution of fumonisins (B1 B2, and B3) and total aflatoxins (B1, B2, G1, and G2) in various corn processed fractions. 92 batches of whole corn and derived dry-milled fractions (animal feed flour, flaking grits, corn flour and corn meal) and cooked and roasted cornflakes fractions were industrially obtained. Samples were analyzed for both groups of mycotoxins by enzyme-linked immunosorbent assay (ELISA). Dry milling of corn led to a heterogeneous distribution of the two groups of mycotoxins in the different parts of the grain, with increased levels in fractions processed from outer layers (animal feed flour and corn flour) and decreased levels in fractions processed from inner portions, such as corn meal and flaking grits. Levels of fumonisins in cornflakes were lower than 400 μg/kg, the maximum tolerable limit set by the EU. By contrast, three samples of final product were found to exceed the aflatoxin maximum tolerable limit of 4 μg/kg. Animal feed flour showed concentration factors of 317 and 288% for fumonisins and aflatoxins, respectively. Food traceability system was used by the industrial companies which processed corn into breakfast cereals. Nevertheless, even though the use of food traceability, which is defined as the ability to trace any food, feed, food-producing animal or substance that will be used for consumption through all stages of production, processing and distribution, only initial fumonisin contamination of whole corn and contamination of animal feed flour and corn flour were found to be correlated.

The authors are grateful to the Spanish Government (CICYT, AGL 2002-00555 and Ramón y Cajal Program).