STUDY OF AFLATOXIN DISTRIBUTION AND OFF-FIELD PRACTICES THAT REDUCE ITS CONTAMINATION IN ARACHIS HYPOGAEA L_ UPPER EAST REGION_GHANA

Abstract

Aflatoxin is a known secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus. They mostly contaminate oil seed crops such as groundnuts. Their impact on food safety and liver related diseases globally is becoming worrisome. This research was conducted in thirty (30) communities across four administrative districts in the Upper East Region of Ghana to determine the aflatoxin distribution in the region and the effect of post-harvest drying and storage treatments on the incidence of aflatoxin contamination in harvested groundnuts. Three drying techniques (Rack, Tarpaulin and Status Quo) methods were studied to determine the most effective technique that reduces aflatoxin to an acceptable level. FluoroQuant Afla reader was used for the aflatoxin analysis and fungal species isolation was done using PDA and tetracycline solution 1.2 mL / 240 mL of PDA. The study revealed that, Bolgatanga municipality had the lowest aflatoxin level of 10.63±6.10 ppb while Kassena/Nankana had the regional highest of 14.14±13.68 ppb. The study also revealed that groundnut dried on tarpaulin effectively reduced aflatoxin level by 58 % with a mean value of 8.40±0.67 ppb. Groundnuts dried on racks and farmers method (status quo) were found to have aflatoxin levels increased by 225.8 % and 53.73 % per the US standard with mean values of 48.87±19.75 and 23.06±14.66 ppb respectively. The fungal species isolated from the harvested groundnuts were; aflatoxicogenic species (A. flavus, A. parasiticus) and non aflatoxicogenic (A. niger, A. fumigatus, and Rhizopus stolonifer). In general, the data showed that aflatoxin levels in groundnuts can be reduced by drying the nuts on a tarpaulin.