Effects of increasing concentrations of sodium sulfite on deoxynivalenol and deoxynivalenol sulfonate concentrations of maize kernels and maize meal preserved at various moisture content.

Under moderate climatic conditions, deoxynivalenol (DON) contamination occurs frequently on cereals. Detoxification measures are required to avoid adverse effects on farm animals. In the present study, a wet preservation method with sodium sulfite (Na2SO3) and propionic acid was tested to titrate the optimum Na2SO3-dose for maximum DON reduction of contaminated maize kernels and meal and to examine the interaction between dose and moisture content in dependence on the preservation duration. The DON concentration decreased with increasing amounts of supplemented Na2SO3 and with increasing duration of the preservation period in a bi-exponential fashion. Additionally, the feed structure and moisture content had a significant influence on the decontaminating effect. Variants with 30% moisture content favored higher DON reduction rates compared to 14% moisture, but especially at low moisture contents, DON reduction was more pronounced in maize kernels than in maize meal. In addition to the decrease of DON, a concomitant formation of three different DON sulfonates was observed which differed in their formation pattern over the time course of preservation. The overall results and statistical analysis clarified that Na2SO3 addition of 10 g/kg maize at 30% moisture for eight days was necessary to obtain a complete DON reduction.