Comparison of Physical Degradation Techniques of Aflatoxin B₁ in Guizhou Tartary Buckwheat Rice

Aflatoxin B₁(AFB₁)contents in tartary buckwheat rice was estimated by HPLC after degradation by microwave,ultraviolet and γ ray irradiation. The microwave power,microwave time,ultraviolet irradiation time,ultraviolet irradiation height and γ radiation dose were investigated. The results showed that:The degradation rate of AFB₁ in tartary buckwheat rice was gamma irradiation > UV degradation > microwave degradation. When the radiation dose was 20 kGy,The degradation rate were 33.6%±1.5%(pollution dose of 7.5 μg/kg),35.1%±1.7%(pollution dose of 30 μg/kg),and 45.7%±1.3%(pollution dose of 60 μg/kg),respectively. Compared to separate degradation technologies,after combining any two or three degradation technologies,the degradation rate was significantly increased compared to the single degradation technique(P<0.05).The combined degradation rates of the three technologies of microwave,ultraviolet and γ ray irradiation reached 51.9%±0.9%(pollution dose of 7.5 μg/kg),66.5%±0.7%(pollution dose of 30 μg/kg),and 71.5%±0.9%(pollution dose of 60 μg/kg),respectively. Three kinds of physical degradation technologies would have certainly application value for low-dose AFB₁ pollution in tartary buckwheat rice.