Ozonation of Brazil nuts: Decomposition kinetics, control of Aspergillus flavus and the effect on color and on raw oil quality

The objective of this study was to evaluate the decomposition kinetics of ozone gas for preservation of Brazil nuts, the effect on Aspergillus flavus and possible effects on color and on raw oil quality. With regards to the saturation process, an exponential reduction of the saturation time was observed, while the saturation concentration increased linearly in the porous medium as the initial gas concentration was increased. Ozone half-life in the Brazil nuts at 25 °C was equivalent to 4.20 min. As for the effect of ozone on A. flavus, at the concentration of 8.88 mg L−1, for 240 min, the gas was able to cause a reduction in the count of microorganisms greater than 3.10 log cycles. Changes in the structure of the microorganisms and color of the colonies were also evidenced. Ozonation did not alter the quality of Brazil nut oil or its lipid profile. From the obtained results, it was concluded that: the initial ozone concentration influences the time and saturation concentration; ozone efficiently inactivates A. flavus in Brazil nuts; and in the conditions adopted for the present study, ozone does not affect the quality of the raw oil, including the lipid profile. •Decomposition kinetics of ozone in media containing Brazil nuts was studied.•The effect of ozonation on Aspergillus flavus was studied.•Ozone was efficient in the inactivation of Aspergillus flavus in Brazil nuts.•The ozonation does not affect the lipid profile of the raw oil of Brazil nuts.