Ultrasound assisted extraction of polyphenolic compounds from red sorghum (Sorghum bicolor L.) bran and their biological activities and polyphenolic compositions

Ultrasonic-assisted extraction (UAE), using aqueous ethanol as the solvent, was firstly applied to extract polyphenolic compounds from red sorghum bran. In this study, ultrasonic time (min), ethanol concentration (%) and solvent to solid ratio (mL/g) were investigated and optimized using a Box-Behnken design. The optimized result for UAE was 21 min of ultrasonic time, 53% of ethanol concentration, and 52:1 mL/g of solvent to solid ratio, 49.743...