PURPOSE: To produce a starch flour for use in SOBA noodle making, which has almost the same properties as of SOBA noodles with microorganisms reduced.

CONSTITUTION: The starting substance of starch is fed into the mixing and granulating machine. For example, about 12wt.%, based on the starch, of an additive solution is added with a binary fluid nozzle for 5min, then granulated for about 1min. The concentration of the additive solution is about 20% in case of low polymerization degree soluble starch, or about 7.5% in case of high polymerization degree. The drying time after granulation depends upon the water content. The water content of the product is preferably about 14W15%.