Preparation method of ferulic acid from corn bran

The invention relates to a preparation method of a ferulic acid from corn bran. The preparation method comprises the following steps: (1) cleaning and drying the corn bran, deactivating enzyme, milling and screening the corn bran to obtain the processed corn bran; (2) adding water in the processed corn bran to be stirred uniformly to obtain slurry; (3) adding high temperature resistant alpha-amylase in the slurry, and performing water bath and vibration to obtain the starch-removed corn bran; (4) cooling the starch-removed corn bran to room temperature, adding compound protease in the corn bran, performing water bath, keeping warm and continuously stirring to obtain the protein-removed corn bran; (5) performing enzyme deactivation, centrifuging and drying to the protein-removed corn bran till constant weight, and obtaining the dried starch-removed protein-removed corn bran; (6) adding a sodium hydroxide solution in the dried starch-removed protein-removed corn bran, performing constant-temperature water bath and centrifuging to obtain a ferulic acid extracting solution; (7) keeping the ferulic acid extracting solution out of the sun and standing, centrifuging, and diluting the extracting solution to 100 mL; (8) concentrating and drying the diluted ferulic acid till constant weight to obtain the ferulic acid coarse powder. The preparation method is simple to operate, low in cost, and high in yield of the ferulic acid.