Aflatoxin Inactivation in Gamma-Ray-Irradiated Almonds

Aflatoxins are foodborne toxins that occur naturally in various crops because of fungal contamination, particularly from two strains, namely Aspergillus flavus and Aspergillus parasiticus. Given their adverse properties, which are teratogenic, mutagenic, and carcinogenic, aflatoxins present a significant public health concern. Consequently, efforts are underway to inactivate aflatoxins and inhibit the growth of these fungi to prevent toxin formation. Since chemical treatments for food products are undesirable or even restricted in some countries, alternative approaches are also implemented. This study investigated gamma-ray (γ-ray) irradiation as a potential method for reducing aflatoxin levels. Specifically, solutions of aflatoxins B1, B2, G1, and G2 were irradiated with doses of 1, 2, 4, and 8 kGy using a cobalt-60 irradiation source. Following γ-irradiation, a notable reduction in aflatoxin levels was observed, particularly for types B1 and G1, which process higher toxicity. This finding suggests γ-irradiation as a feasible method for aflatoxin deactivation. Additionally, as a proof of concept, almond samples spiked with aflatoxins and A. flavus were irradiated. The results showed a decrease in both aflatoxin levels and microbial load in these samples. Overall, these findings indicate that γ-irradiation is a promising approach to aflatoxin reduction, microbial decontamination, and the potential extension of almonds’ shelf life.