Efficacy of Ozone Treatment on Mycotoxins and Fungal Reduction in Artificially Contaminated Soft Wheat Grains

Abstract

The effects of O3 concentration, exposure time and grain mass were evaluated on the levels of deoxynivalenol, aflatoxins and total fungal count (TFC) in wheat grains, using a full 23 factorial design. Grain samples were contaminated with fungal conidia and spiked with mycotoxins standards and then submitted to ozonation treatments. The most significant reductions obtained for deoxynivalenol and total aflatoxins corresponded to 64.3 and 48.0%, respectively. TFC reduced approximately 3.0 cycles log cfu/g of wheat grain. O3 concentration and exposure time influenced (P < 0.05) positively the reductions of both mycotoxins and TFC, while the grain mass had a negative effect on both responses. The most significant reduction in TFC and mycotoxin levels was achieved by using 60 mg/L of O3 for 300 min, with 2 kg samples. Gaseous O3 can be considered an excellent method for remediation of these contaminants. Practical Applications Gaseous ozonation is an interesting nonthermal technology that can be applied to reduce fungal and mycotoxin contamination in wheat grains (Triticum aestivum L.). The O3 concentration and exposure time positively influence reductions in mycotoxins and fungi count, while grain mass has a negative effect on both variables. Using 60 mg/L of O3 at 300 min of exposure and 2 kg grain samples (11.3% moisture content) is possible to obtain reductions of 3.0 cycles log cfu/g in total fungal count, 64.3% in DON levels and 48.0% in total aflatoxin levels. Data found in this research should contribute in greater interest of ozonation by the food industry and consequently a wider popularization of ozonized products by consumers.