Advanced grain cleaning solutions for mycotoxin reduction

Mycotoxins in the feed and food chain are a major threat both for human and animal health. Just a few highly contaminated grains can make a whole lot unsafe for use as human or animal nutrition. For efficient mycotoxin reduction, a full value chain approach is needed, starting from measures to prevent contamination in the field, to control measures to avoid mycotoxin production during storage and over the process line, until final consumption. Grain cleaning is the most effective post-harvest mitigation strategy to reduce high levels of mycotoxins due to the efficient removal of mold-infected grains and grain fractions with high mycotoxin content. Several studies have been performed during the last years to investigate the reduction of deoxynivalenol in wheat and barley, ergot in rye, and total aflatoxins in peanuts and maize. In this study, the reduction of Fusarium mycotoxins content in maize, i.e. deoxynivalenol (DON), zearalenone (ZEA) and fumonisins (FBs), was tested. Three online cleaning processes were used: (i) mechanical size separation and dust removal by aspiration, (ii) separation based on density differences, and finally (iii) optical sorting. Samples were taken dynamically according to the Commission Regulation No. 401/2006 along the entire process line, including cleaned and rejected project streams. Mycotoxin analyses were performed of water-slurry aggregate samples by validated HPLC methods based on immunoaffinity column clean-up of extracts. The overall reduction rate were up to 55% for DON, up to 100% for ZEA, and up to 65% for FBs. High levels of mycotoxins were found in all rejected fractions.