Abstract: Given the fact that moist-heat and alkaline conditions can destroy mycotoxins, corn germ was steamed with superheated steam at 115 ℃ for 30 min after adjusting its moisture content to the suitable value for steaming (14%) with different concentrations of NaOH solution. The contents of aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON) in steamed and unsteamed corn germ as well as crude oil prepared from each of them were tested to explore the effect of dilute alkali steaming of corn germ on the degradation of mycotoxins in corn germ and crude corn oil. The results showed that steaming corn germ with 5.29% NaOH exhibited the highest degradation of ZEN and DON, whose contents decreased by 64.69% (246.25 versus 697.41 μg/kg) and 66.78% (802.83 versus 2 417.07 μg/kg) in steamed corn germ, also decreased (140.02 versus 266.44 μg/kg, and 108.47 versus 150.76 μg/kg) in the resulting corn oil compared with their respective unsteamed counterparts. Steaming corn germ with 6.55% NaOH resulted in the highest degradation of AFB1, whose content decreased by 90.30% (0.77 versus 7.91 μg/kg) in steamed corn germ and also decreased (0.51 versus 2.11 μg/kg) in the resulting corn oil compared with their respective unsteamed counterparts. As the alkali concentration increased, the color of both corn germ and the resulting corn oil became darker, and the acid value and peroxide value of the oil were significantly reduced. The dilute alkali steaming method can effectively reduce the mycotoxin content in corn germ as well as the resulting crude oil and corn germ meal, thereby improving the safety of corn oil and meal for human and animal consumption respectively.

Key words: corn germ, steamed corn germ with dilute alkali, corn germ oil, a?atoxin B1, zearalenone, deoxynivalenol, degradation