Abstract:The activity of procyanidins in peanut red coat was studied.Procyanidins were extracted from peanut red coat by ultrasound-assisted enzymatic method，and the extraction conditions were optimized by establishment of a multivariate regression model.The DPPH，hydroxyl，and ABTS+ radical scavenging activities of five peanut red coat samples were compared，and the composition of procyanidins in peanut red coat was analyzed by high performance liquid chromatography-mass spectrometry（HPLC-MS）.The results showed that the yield of procyanidins was 10.07% after three times of parallel extraction under the conditions of 5.00% enzyme addition，20.00 min sonication，and 90 .00 min enzymatic digestion.The procyanidins from the red coat of the peanut cultivar “Jihua 27” had the strongest ability to scavenge DPPH，hydroxyl，and ABTS+ radicals at 91.04%，76.64%，and 87.11%，respectively.The HPLC-MS results showed that the crude extract of “Jihua 27” peanut red coat contained procyanidins A1，A2，B1，and B2，catechins，and epicatechin，in which procyanidin A2 had highest content of 5.33 mg/g.Procyanidins in peanut red coat had strong antioxidant activity and were potential raw materials for the development of natural antioxidants.