Abstract:In order to study the effects of micronization on crystal structure and direct ethanol fermentation of corn flour，corn flour samples were prepared by wet-milling，and then the direct ethanol fermentation of corn flour were carried out by using commercially available glucoamylase and yeast.The commercial corn flour with a median diameter of 273.6 μm was micronized to 8.3 μm in median diameter by wet-milling.And X-ray diffracometry revealed that the crystals of starch granules in the corn flour could be destroyed by wet-milling.The fermentation rate and alcoholicity of micronized corn flour were significantly higher than that of the commercial corn flour.And when the initial pH and concentration of feed mixture were 6 and 20%respectively，the samples ferment most efficiently with alcoholicity of 11.2%.The results indicated that wet-milling led to the destruction of corn flour crystal structure，which resulted in a remarkable increase of alcoholicity in the ethanol fermentation of corn flour.