Optimization of Ultrasound-Assisted Alkali Alcohol Extraction and Macroporous Resin Purification of Ferulic Acid from Corn Husk

To explore the extraction and purification process of ferulic acid from corn bran, ferulic acid from corn husks was extracted by ultrasound-assisted alkali alcohol method. The best extraction conditions were obtained by using the content of ferulic acid in the crude extract of corn husk as the index through single factor tests and response surface optimization test. Further purification of corn ferulic acid was used macroporous adsorption resin method, and suitable resin was selected by static adsorption method. Determined the optimal sample loading amount in the dynamic adsorption method, and obtained the optimal purification process conditions using recovery rate as an indicator through single factor experiments and response surface optimization experiment. Results showed that, the best extraction conditions of ferulic acid from corn bran were obtained as follows: Solid-liquid ratio 1:12 g/mL, mass concentration of lye was 4%, alkali-alcohol ratio was 2:1, ultrasound time 30 min, ultrasonic thermometer 59℃, ultrasonic power 229 W, and the amount of ferulic acid extracted could reached 22.31 mg/g under these conditions. The purification of ferulic acid was performed using HPD-100 macroporous adsorption resin. The optimal loading volume was 6 times the bed volume. The optimal purification process conditions are as follows: Sample loading concentration 0.3 mg/mL, loading flow rate 3 mL/min, mass concentration of ethanol 75%, elution flow rate 1 mL/min. Under these conditions, the recovery rate of ferulic acid from corn peel was up to 95.17%, and the purity of ferulic acid was 81.56%. This experiment increased the added value of corn brans, and would provide the theoretical basis and data support for the further processing of corn brans and the development of ferulic acid.