UTILIZAÇÃO DO OZÔNIO NA DESCONTAMINAÇÃO DE GRÃOS DE MILHO

Abstract

This study aimed to evaluate the use of ozone gas in the degradation and decontamination of aflatoxin and polycyclic aromatic hydrocarbons in corn kernels. We used two lots of corn (Zea mays L.) produced in the Rio Verde region - GO: one with a moisture content of approximately 14% (wb) and contaminated with aflatoxins, and other newly harvested with a water content of approximately 16% (wb). It was used to dry the natural convection with direct fire furnace in both lots, to evaluate degradation of aflatoxins with low water content and also contaminate the grain with polycyclic aromatic hydrocarbons. Then chromatographic analysis of samples was performed to identify and quantify mycotoxins aromatics. Subsequently the pellets were ozonized using ozone generating equipment oVEC- XT with based dielectric discharge cm coupled to a PVC container with a concentration of 1.74 mg L-1 and 112 min of soak time. The first batch was divided in two parts: one with a low moisture content and the other part remained without drying. The ozonation times used were 0, 2, 4 and 6 hours and 1.0 kg of grain for each repetition in order to decontaminate the grains. The ozonated grains were evaluated for: moisture content, germination percentage, germination speed index, classification of grain, color analysis (L *, a *, b *), and chemical composition. The experiment was conducted using a completely randomized design (CRD) in a factorial scheme. Treatments (with and without drying) had no effect on the electrical conductivity variable, rot grains, L *, a *, b *, moisture content, germination rate index, the centesimal composition moisture content, ash, lipids and xvi carbohydrates. The O3 time influenced the fermented grains. Regarding mycotoxins time ozonation showed no efficiency. The second batch of corn contaminated with PAH's had its low moisture content to approximately 11% (wb). Then, the samples were analyzed by high-performance liquid chromatography (HPLC) with fluorescence detection for quantifying the compounds and then were sprayed with the ozone gas using seven times: 0, 4, 8, 12, 16, 20 and 24 h in three replicates and 1.5 kg of grains. After fumigations evaluations were carried out as: moisture content, germination percentage, color analysis (L *, a *, b *, C * and h °) and chemical composition. The experiment was conducted using a randomized design (CRD). Data were analyzed using analysis of variance and means were compared by the Scott-Knott test at 5% significance. There was no effect of ozone on the moisture content variables, electrical conductivity, germination percentage, h ° C *, L *, a * and b *, carbohydrate, crude protein and crude fiber. The ozonation times had an effect on lipid content, ash and moisture content. Regarding the degradation of the hydrocarbons, there was no effect of ozonation time. It follows then that the ozonation time and concentration used were not enough to decontaminate all aflatoxins and degrade the PAH's present in corn grain.