Reduction of Aspergillus flavus and aflatoxin on almond kernels using gaseous chlorine dioxide fumigation

Abstract

The almond industry suffers product losses caused by mold growth and toxin contamination. Gaseous chlorine dioxide (ClO 2 ) has the potential for postharvest reduction of mycotoxic Aspergillus flavus . In this study, almonds inoculated with A. flavus were fumigated with gaseous ClO 2 for 1, 2, 3, 8, 12, and 24 h using a dry precursor sachet batch method. The headspace concentration ranged from 0.5 to 2.4 mg/L, depending on initial dosing and time. At its highest concentration, gaseous ClO 2 demonstrated an 84.4 % degradation efficiency of aflatoxin B1 (AFB1) with a reduction of 2.4 log CFU/g of A. flavus on almond kernels. Additionally, suppression of AFB1 continued after one-month storage at 4 °C. No significant oxidative effect and color difference ( ΔE ) was observed on the treated kernels. The almond industry can apply gaseous ClO 2 technology to reduce mold contamination and product losses.