Fungal mycotoxins reduction by gamma irradiation in naturally contaminated sorghum

Abstract

The objective of this study was the evaluation of the effects of different gamma irradiation doses on the survival of natural mycoflora as well as on the reduction of mycotoxin contamination (ochratoxin A [OTA] and aflatoxin B1 [AFB1]) in naturally contaminated sorghum samples. Mycotoxin levels were determined by ultra-high-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). The results have demonstrated that the dose of 3 kGy was sufficient to eliminate 90% of the natural fungal load of sorghum. Increasing gamma irradiation dose showed significant effects (p < .05) on initial mycotoxin content. At radiation dose of 10 kGy, maximum reduction of 59% and 32% were achieved in naturally contaminated sorghum for AFB1 and OTA, respectively. The obtained results clearly showed that gamma irradiation can be a promising method to control fungal and mycotoxin contamination in sorghum. Practical applications Sorghum is an important staple cereal crop intended for human foods and animal feeds worldwide. This study investigated the potential application of gamma irradiation to reduce fungal load and the mycotoxins (OTA and AFB1) in naturally contaminated sorghum. The results showed significant decrease in the natural fungal load. The amounts of OTA and AFB1 in sorghum were also reduced by applying this method. The results showed that gamma irradiation was a promising method to control fungal and mycotoxin contamination in sorghum within the permissible dose range applicable to food preservation (≤10 kGy).