Optimization of procyanidins extraction from pericarpof Litchi chinensis by response surface methodology

LI Huan-qing，DENG Hong，ZHANG Shu，HU Xue-yan，CUI Yue-xin，CHI Xu-ying（Institute of Materia Medica，Guangdong Pharmaceutical University/Guangdong Provincial Key Laboratory of Advanced Drug Delivery，Guangzhou 510006，China）Abstract：To optimize the conditions for extracting procyanidins from pericarp of Litchi chinensis，Heiye growingin western Guangdong was used as experimental material. Based on single factor test and the Box-Behnken designprinciples，using procyanidins yield as the index，a response surface optimization test was established by using Design-Expert8.0 design software. And the efficiency of antiradical of procyanidins extracted from pericarp of Litchi chinensiswas determined by the DPPH assay. The results show that the optimized extraction conditions of procyanidins frompericarp of Litchi chinensis were obtained as follows：ethanol concentration was 68%，extraction temperature was59℃，extraction time was 93 min，solid-liquid ratio was 20∶1 and extracted twice. Under these conditions，the yield ofprocyanidins was 5.26%. The yield of procyanidins increased after optimizing，and the ability of antiradical of the purifiedprocyanidins was similar or even better than Vc.