Optimization of ultrasound-assisted extraction conditions of antioxidative components from Arundina graminifolia by response surface methodology based on DPPH radical scavenging assay.

Response surface methodology(RSM) was employed to optimize conditions for ultrasound-assisted extraction(UAE) of antioxidantive components from Arundinagraminifolia. 1,1-diphenyl-2-picryl-hydrazyl(DPPH) free radical scavenging assay was used to evaluate the activity of antioxidative components. Based on the single-factor test, we identified extraction time, ethanol volume fraction, extraction temperature and liquid-solid ratio as the main variables that influence DPPH free radical scavenging activity of A. graminifolia extract. The optimal conditions to achieve the maximum activity were determined as follows: extraction time 35 min, extraction temperature46 degrees C, ethanol volume fraction 74% and liquid-solidratio27 mL.g(-1). The scavenging rateof 78.71% was achieved under the optimal extraction conditions, which was well in agreement with the optimal predicted values (79.16%). This extraction method was simple and efficient and provided a method of sample preparation to determine DPPH radical scavenging activity of total antioxidative components from A. graminifolia. The research also provided a reference for full utilization of A. graminifolia and identified a technique to extract antioxidative components.