Optimization of ultrasonic-assisted extraction (UAE) of phenolics and antioxidant compounds from rhizomes of Rheum moorcroftianum using response surface methodology (RSM)

This study for the first time designed to optimize the extraction of polyphenols compounds from rhizomes of Rheum moorcroftianum using response surface methodology (RSM). Solvent was selected based on the preliminary experiments, and a four-factors-three-level, Box-Behnken Design (BBD) including 29 experimental runs. The polyphenols content and antioxidant activity was significantly (p < 0.05) affected by vessel diameter - 6 cm (X-1), sample to solvent ratio - 1:28.42 g/mL (X-2) and extraction temperature - 37.11 degrees C (X-3) under ultrasonic assisted extraction (UAE). The measured parameters were found in accordance with the predicted values. High Performance Liquid Chromatography (HPLC) analysis in optimized condition revealed the presence of 12 phenolic antioxidant compounds with the highest concentration of chlorogenic acid (26.68 mg/g). The results indicate that optimization of extraction conditions in R. moorcroftianum is critical for precise quantification of antioxidant phenolics and its further utilization in industry.