Evaluation of biobased solutions for mycotoxin mitigation on stored maize

Worldwide maize (Zea mays L.) is one of the most important cereals in food and feed. It is highly susceptible to fungal contamination and when mycotoxigenic fungi are present, maize also shows high susceptibility to mycotoxin contamination at pre and post-harvest. The adoption of good pest management practices in the storage of maize is mandatory for grain quality assurance and the search of biobased solutions to avoid the mycotoxin contamination is a current challenge.

The objective of this study was to evaluate the effectiveness of the biobased products mustard powder and rice bran oil as post-harvest mitigation strategies towards maize quality control. Dried maize (moisture <15%) was stored in barrels simulating the real ‘in silo’ conditions during ten months.

The application of mustard powder (0.2%, m/m) showed an apparent negative effect on aflatoxins biosynthesis and after six months of storage the levels of aflatoxins (Afla B1 + Afla B2) were lower than in the control (4.8 µg kg^-1 and 7.6 µg kg^-1, respectively). However, the levels of fumonisins in maize increased during first six months of storage. The application of rice bran oil (1%, v/m) shows apparent effect on the reduction of fumonisins on the maize grain during the first six months of storage when compared with the control.

The results obtained with mustard and rice bran oil applications for mycotoxin mitigation in stored maize under real ‘in silo’ conditions are promising, but further research are needed for deliver useful recommendations to the different maize chain stakeholders.