Abstract: The extraction process of non-extractable polyphenols (NEPPs) from Pyracantha fortuneana was optimized by response surface methodology (RSM).The content and antioxidant capacity of NEPP was determined.Taking extraction yield of NEPP as evaluation index and Folin-Ciocalteu colorimetry as assay method,on the basis of single factor experiments,the effects of ethanol concentration (%,v/v),the proportion of ethanol in sulfuric acid-ethanol (%,v/v),solid to liquid ratio (g/mL),extraction time (h) and temperature ( ℃) on the NEPP yield was investigated.In addition,Box-Behnken design was further adopted to optimize extraction process of NEPP from P.fortuneana. Moreover,the antioxidant capacity of the extracted NEPP was determined by ABTS and FRAP assays.The optimal extraction conditions was as follows:extraction time of 2.68 h;the volume fraction of ethanol,94.44% (v/v);extraction temperature of 83.47 ℃.Under these conditions,the extraction yield of NEPP and EPP reached 167.328 mg/g and 40.4 mg/g,respectively.RSM was feasible to optimize extraction process of NEPP from P.fortuneana. NEPP accounted for a high proportion of 80.55% in TEPP and the NEPP content had positive correlation with its antioxidant capacity.

Key words: Pyracantha fortuneana, non-extractable polyphenols;response surface methodology;antioxidant