Tracing interactions among column height, exposure time and gas concentration to dimension peanut antifungal ozonation

Ozone presents high oxidative potential and a broad antimicrobial spectrum. We evaluated the effect of ozonation on the control of fungi and on quality of peanuts. A PVC cylindrical column of 0.15 m diameter was used for peanut ozonation, with the kernels column height equivalent to 0.75 m. Peanuts were placed in organza bags and arranged at 0, 0.25, 0.50 and 0.75 m from the base of the column. Concentrations of 2.77 and 6.41 mg/L of ozone were applied, with exposure times of 0, 3, 6, 9 and 12 h. The effect of ozone on several parameters including percentage of kernels infected by fungi, moisture content, color and acceptance of kernels, peroxide value and acidity of peanut oil was assessed. The percentage of peanut kernels infected by aflatoxigenic fungi was significantly reduced and it was more accelerated in the concentration of 6.41 mg/L, at lower layers of the kernels column and at longer exposure times. In general, ozonation did not significantly affect the quality of the kernels. Acceptance of ozonated peanuts were equal or higher than non-ozonated kernels. Ozonation can be used to control aflatoxigenic fungi in peanut kernels without affecting product quality.