Effect of dry heat and sunlight on the aflatoxin content in compounded feed

This study was undertaken to confirm the effect of drying on aflatoxin degradation in feed. Compounded feed spiked with 50 mg of ground broken rice containing crude aflatoxin material (AFB₁ 605–655 ppb) was kept in hot air oven at 60, 80, 100 and 120°C for 0, 30, 60, 120 and 180 min. Maximum aflatoxin reduction (80–90%) was observed at 120°C for 120 and 180 min of drying. Moderate reduction (36–40%) was observed at 80°C for 120–180 min of drying. However, drying of aflatoxin contaminated feed at 60°C did not result in much reduction in aflatoxin content even upto 180 min. In an another study, aflatoxin contaminated feed (AFB₁ 502 ppb) was exposed to sunlight for 0–14 hr (ambient temperature 27–35°C). Aflatoxin content in feed reduced linearly with increased duration of drying in sunlight. About 27% aflatoxin reduction was noticed within 30 min of exposure and 90–94% of reduction was recorded after 10–14 hr (2 days of 7 h each) of sun drying. It was concluded that sun drying of feeds was an effective and practical way of reducing the aflatoxin level in contaminated feeds.