A Cleaner Approach for Corn Starch Production by Ultrasound-assisted Laboratory Scale Wet-milling

An ultrasound-assisted laboratory scale wet-milling process was explored and the yield, purity and properties of corn starch were studied. The highest starch yield was obtained when the steeping time was 32 h, the concentration of sulfur dioxide was 0.05 % (w/w), the ultrasonic duration time was 15 min, the ultrasonic power was 200 W and the solid-liquid ratio of the slurry was 1:1 (g/mL). Starch yield increased by 10 % using the ultrasound-assisted wet milling (68.96 %) compared to traditional wet milling (62.48 %). The purity of starch remained unchanged. The results of X-ray diffraction, particle size, optical microscopy, scanning electron microscopy and differential scanning calorimeter revealed that the granular and crystalline structure and thermal properties were not statistically different for the starches isolated by two methods. The starch isolated using ultrasound-assisted wet milling exhibited lower yellowness, higher peak viscosity, similar thermal properties, and larger moduli compared to starch extracted by traditional wet milling.