Corn is one of the most cultivated cereals in Brazil. However, its grains are constantly exposed to contamination by mycotoxins. Corn grits are used by the food industry to produce a large variety of corn products such as canjiquinha, a cultural food easily purchased by the Brazilian consumer at low prices. Some studies have demonstrated high contamination of this product by aflatoxins (AFs), representing a potential risk of exposure due to such a contamination. In this study, the efficacy of gaseous ozonation was evaluated on the levels of aflatoxins and on the microbial contamination of corn grits. The application of gaseous ozone was tested in different combinations of exposure time, ozone concentration, and canjiquinha mass. After the ozonation treatment, samples were collected for aflatoxin and microbiological analyses. Aflatoxins were evaluated using a high-performance liquid chromatography with fluorescence detection (HPLC-FD) system using pre-column derivatization, and the microbiological analyses were carried out for toxin-producer fungi and mesophilic bacteria. After ozone detoxification, results showed reductions up to 57% in aflatoxin levels. Total fungal count was reduced around 3.0 cycles log CFU g⁻¹ and total mesophilic counts were reduced to non-detectable levels. These results demonstrated that ozonation is an effective alternative for reducing aflatoxin and microbial contamination in products like canjiquinha, thereby improving food safety.

Gaseous ozonation, an emerging technology, is applied to microbiological decontamination and to the degradation of residues and contaminants in wheat grains. However, due to its high oxidizing capacity, ozone may cause undesirable effects on the quality of grains or in their derivatives. This study aimed to evaluate the influence of ozone gas on wheat grain quality when exposed to different levels of ozone concentration, exposure time, and grain mass, using a full 2³ factorial design. After the milling of ozonized grains, two fractions were evaluated: flour (A) and bran plus germ (B). In fraction A, the quality of the wheat flour was analyzed by both alveography and farinography. The flour extraction rate, falling number and gluten contents were also measured. The chemical and mineral profiles were determined in both fractions. A sensory evaluation, using the difference-from-control test, was applied to investigate the possible differences in aroma or in overall appearance of the flour obtained from the ozonized grains. The results showed that ozone concentration (60 mg/L) positively affected (p < 0.05) the toughness and the falling number of the flour. The other parameters of alveography, as well as farinography, gluten content, chemical composition, mineral, and sensory profiles were not affected (p > 0.05) by ozonation. This study demonstrated that gaseous ozonation, when applied under the conditions of 10 to 60 mg/L, from 2 to 5 h of exposure, grain mass from 2 to 5 kg, does not cause any negative impact on the wheat quality.