DOI: 10.21276/sjet

Pages: 146-152

Antifungal properties of ozone (O3) gas were evaluated in stored naturally contaminated dry maize grains. An experimental design was applied at three concentrations (20, 40, 60 μmol/mol) and different exposure times (30 to 180 min) for Groups I to III, respectively. O3 gas had evaluated its antifungal efficiency at Day zero and after 30 days of storage, at the lower and upper layers of each silo. Regarding O3 concentration, it was observed with the increase of its concentration (from 20 to 60 µmol/mol) a decrease of 2.5x10(16.2%) and 0.5x10(3.2%) CFU/g in the silo upper and the lower layers, respectively. On the other hand, regarding O3 time of exposure, when the ozonation time increased (from 30 to 180 min) on contaminant mycoflora there was a total fungi load decrease of 1.0x10(6.5%) and 0.5x10(3.2%) CFU/g in the upper and lower layers, respectively exposed to O3 gas. The response surface presented the maximum of 94.5% of spores inhibition. After 30 days of storage no statistical difference was observed between the applied treatments. Therefore, both treatments were effective. It was observed at Control silo (no gas treatment) at day 30th a total fungi load of 22x10 CFU/g.