Ultrasound-assisted enzymatic extraction, process optimization, and antioxidant activity of polysaccharides from sugarcane peel

In this research, ultrasound-assisted enzymatic extraction of sugarcane peel polysaccharides and optimization of process conditions were used to investigate their properties and antioxidant activities. The effects of liquid-material ratio, ultrasonic temperature, ultrasonic time, and cellulase dosage on the extraction rate of SPP were investigated by one-way experiments and response surface analysis to determine the optimal process conditions. Meanwhile, structural characterization (FT-IR and NMR analyses) and antioxidant activity studies (DPPH and hydroxyl radical scavenging rates) were carried out to determine the total sugar content of SPP. The results showed that the optimal conditions for SPP extraction by the ultrasound-assisted enzymatic method were 40 mL/g liquid-material ratio, 50 °C ultrasound temperature, 40 min ultrasound time, 5% cellulase enzyme dosage, and the yield of SPP was 5.38% and the total sugar content was 75.52% under these conditions. The extracted SPP showed some scavenging ability for both DPPH and hydroxyl radicals, and the scavenging rate for both was 54.63% and 33.91%, respectively, when the mass concentration of the SPP solution was 4 mg/mL. The present study demonstrated that ultrasound-assisted enzymes can effectively extract SPP with antioxidant activity, which provides a theoretical basis for developing and utilizing sugarcane peel polysaccharides and has potential application value.