Gamma Irradiation for the Inactivation of Aspergillus flavus Link in Copra (Dried Cocos nucifera L. Meat)

Abstract

Aspergillus flavus is a known source of aflatoxin and other carcinogens that contaminates perishable goods such as copra, one of the top exports of the Philippines. Fungal contamination in perishable products has caused post-harvest losses and a significant threat to food safety and security. Existing methods to control or prohibit the growth of fungi have been a tedious process proven to be open to subsequent contamination. This study assessed the capability of gamma irradiation in inactivating A. flavus in copra. Locally acquired copra was inoculated with 5.8 × 103 CFU⁄ml of A. flavus’ spores. The contaminated copra was irradiated with varying doses of gamma radiation (0.3, 0.7, 1, 3 kGy). Results showed a decreasing trend in the fungal count as the absorbed doses of gamma irradiation increased. Irradiation of 0.7 kGy achieved a significant reduction of fungal count satisfying regulatory limits. The largest reduction in the fungal count was achieved by 3 kGy with < 1 log CFU⁄ml molds and yeast count (MYC). This study concludes that gamma radiation is effective in inactivating A. flavus.