US Patent 7501550 Method of destroying seeds

A method of sterilizing seeds comprises heating the seeds to substantially 95° C. or higher and maintaining same at that temperature for substantially 30 minutes. Preferably a combination of steam and microwaves is used to maintain the temperature. Dampening the seeds with steam and water at the start of the process helps the microwaves work more efficiently in maintaining temperature. The method further comprises treating the seeds with ozone which functions both to sterilize seeds as well as to sterilize pathogenic organisms and to degrade residual herbicides, pesticides and like chemicals that may be present in a seed sample. An auger conveyor (7) carries the seed through the process. Temperature sensors (13) monitor the temperature of the seeds and control the speed of the auger so that the seeds are maintained at substantially 95° C. for substantially 30 minutes prior to exiting the output end of the auger conveyor (7). Ozone sensors (17) monitor ozone concentration in order to maintain a concentration of ozone effective to sterilize biological materials as well as to degrade residual chemicals present in seed samples. The auger (7) continuously agitates the seed to expose the seeds to the microwaves and ozone.