Aflatoxin contamination is a serious problem in the global food supply chain. This study was aimed at investigating the use of ultraviolet radiation (UV), hydrogen peroxide (H2O2), and their combination to detoxify aflatoxin in contaminated peanuts, as well as the quality changes in peanut kernels after treatments. To analyze aflatoxin concentration changes, a method employing immunoaffinity column and normal phase HPLC-FLD was developed. The method had better performance and less time and preparative procedures than that of the official method. To determine the uniformity of UV radiation, peanuts were coated with AgCl as the UV dosimeter and rotated in a drum at different speeds. The dose of radiation received on each area of peanuts was measured by color change after UV treatment. Rotating the drum at 11 rpm uniformly distributed UV radiation on peanuts and increased aflatoxin reduction by 23%. To evaluate the effects of different wavelengths on aflatoxin reduction and oil quality of peanuts, three low-pressure UV lamps emitting UV-A, UV-B, and UV-C were used to decompose aflatoxin. The low-pressure UV-A lamp demonstrated a higher aflatoxin reduction (26%) in an hour of irradiation than that of UV-B (16%) or UV-C (21%) and had a lower effect on oil quality of aflatoxin-spiked peanuts than those treated by UV-C. To understand the interaction between the contaminated peanuts and H2O2, peanuts were subjected to a short-time roasting to inactivate the catalase followed by the treatment with 30 g/hg of H2O2 at 50˚C. A 90% aflatoxin reduction was observed in aflatoxin-spiked peanuts after being subjected to the treatment for 8 h, but the oil quality was not seriously affected. The aflatoxin reduction found in peanuts was higher than in the model solution, indicating that peanuts may assist in aflatoxin degradation. To further improve the aflatoxin reduction efficiency, low-pressure UV-C lamps and H2O2 were combined to decompose aflatoxin in spiked peanuts. The treatment reduced 33% of aflatoxin in an hour. The oil quality was slightly affected. The residual H2O2 was completely removed by drying treated peanut at 35˚C for 12 h. These results indicate that the combination treatment significantly increased aflatoxin reduction efficiency.
