Aflatoxin M1 degradation using high voltage atmospheric cold plasma (HVACP) technology

Abstract

ABSTRACT Aflatoxins are one of the highly toxic secondary metabolites with high decomposition temperatures, ranging from 237 °C to 306 °C. Therefore, non-thermal treatments are preferred to ensure safe food while preserving food quality. High voltage atmospheric cold plasma (HVACP) is a novel non-thermal technology with the potential to reduce contaminants (e.g. mycotoxins) owing to reactive species such as ozone. Therefore, the aim of this study was to investigate the efficacy of HVACP to degrade Aflatoxin M1 (AFM1) in pure water. A dielectric barrier discharge HVACP was performed at 90 kV using modified air (MA65: 65% O2, 30% CO2, 5% N2) fill gas for 1, 3, and 5 min in a direct and indirect mode with no post-treatment or 4.0 h post-storage at room temperature. The chemical properties of water were evaluated. Ozone concentration in both gas and liquid phases was also measured. A 77% reduction of AFM1 was observed after 1 min of direct treatment with no post-treatment storage. The nitrate and peroxide contents after 1 min of direct treatment were 4.50 ± 0.70 and 9.5 ± 0.70 mg/L, respectively. Longer treatment time and direct mode of exposure resulted in a higher ozone concentration in either the gas or liquid phase. These results demonstrate the potential of HVACP as a non-thermal treatment for reducing AFM1 concentration. HVACP was capable of significantly degrading AFM1 using a very short treatment time and 4.0-h post-treatment storage.