Survey of Chinese Cowpea Cultivars for Phenolic Compounds and Antioxidant Activity

Distribution of phenolic compounds and antioxidant activities was surveyed in 24 varieties of Chinese cowpea from 4 provinces. Identity of phytochemicals were determined by UPLC-ESIQTOF-MS/MS and quantified by HPLC-ESI-QqQ-MS/MS. Seven phenolic acids, 16 flavonoids and 9 other compounds were identified and several of these were quantified. Quercetin-3-glucoside and kaempferol-glucoside were the major phenolic compounds. In addition, our study indicated that OJYDH cultivar from Jiangxi province had the highest total phenolic content, total flavonoid content and stronger antioxidant activities than other cowpea cultivars. This study made a comprehensive investigation on antioxidants from cowpea and provided the useful data to support its function.