Abstract:To establish the extraction technology of polyphenols from lotus root, the polyphenol yield and DPPH free radical scavenging rate were investigated to optimize the technological parameters. Then, the polyphenol composition and antioxidant activity of extracts were comparatively analyzed. The parameters of technology A optimized by polyphenol extraction yield were as follows: volume ratio of hydrochloric acid to methanol was 2278 (VV), homogenization time was 6.8 min and homogenization speed was 10 500 r/min. Those of technology B optimized by DPPH free radical scavenging rate were as follows: volume ratio of hydrochloric acid to methanol was 1981 (VV), homogenization time was 8.6 min and homogenization speed was 9 100 r/min. The effects of experimental factors on polyphenol extraction yield and DPPH free radical scavenging rate could be both ordered as: hydrochloric acid to methanol > homogenization time > homogenization speed. Technology A showed a higher extraction yield (165.85 mg GAE/100 g·FW) than technology B (P<0.05), and their IC50 values of DPPH free radical scavenging were 4.75 and 6.83 μg GAE/mL, respectively. The results indicate that technology A better fits the extraction of antioxidant polyphenols from lotus root.