Phenolics, anthocyanins and antioxidant activities in waste products from different parts of purple waxy corn (Zea mays l.)

The objective of this study was to evaluate total phenolic content (TPC), total anthocyanin content (TAC), antioxidant activities (AOA) and identify the components of phenolic and anthocyanin in each type of purple waxy corn (PWC) waste, including tassel, cob, kernel pericarp and silk. The results revealed that the silk had the greatest amount of TPC related to the highest AOA, while the cob had the highest TAC. Cyanidin-3-glucoside was the dominant anthocyanin in PWC, followed by peonidin-3-glucoside and pelargonidin-3-glucoside in rank order. Protocatechuic acid was the most abundant phenolic compound in kernel pericarp and silk, while rutin was the dominant component detected in tassel and cob. Additionally, hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic and sinapic acid as well as quercetin and kaempferol were also detected in different parts of PWC.