Use of gaseous ozone to reduce aflatoxin B1 and microorganisms in poultry feed

• Poultry feed was ozonated at the concentrations of 2.8 and 5.3 mg/L for up to 240 min.
• Ozonation for 240 min yielded up to 86.4% reduction in the aflatoxin B1 level.
• Ozonation for 120 min resulted in microbial reductions ranging from 2.3 to 3.2 log CFU/g.
• Ozonation at 2.8 mg/L up to 120 min did not caused significant changes in the lipid oxidation.

This study was undertaken to evaluate the efficacy of gaseous ozone for the degradation of aflatoxin B1 (AFB1) and inactivation of indigenous microflora in poultry feed. Feed samples were treated with continuous stream of two different constant concentrations (2.8 and 5.3 mg/L) of ozone at room temperature up to 240 min. The initial AFB1 level in artificially contaminated feed samples, determined as 32.8 μg/kg, decreased by 74.3 and 86.4% after 240 min of exposure at 2.8 and 5.3 mg/L, respectively. At the both ozone concentrations, 240 min exposure was reduced the aerobic plate and yeast and mold counts below the detection limit (<10 CFU/g) with a reduction more than 3.2 and 2.7 log, respectively. The thiobarbituric acid reactive substances (TBARS) assay indicated that no significant (P ≥ 0.05) increase occurred in the level of lipid oxidation in feed samples during 120 min ozonation at 2.8 mg/L. At the end of the 240 min of exposure at 2.8 and 5.3 mg/L, initial TBARS concentration, determined as 2.4 mg/kg, reached to 4.4 and 5.3 mg/kg with a significant (P < 0.05) increases, respectively. The results presented in this study suggested that significant (P < 0.05) reductions in the AFB1 level and microbial population can be achieved in poultry feed by ozonation with an acceptable changes in lipid oxidation.