In this study, we collected and prepared ethanol extracts from 30 vegetable and fruit by-products. The extracts were screened on antioxidant activities using three methods including determination of total phenolic content (TPC), DPPH free radical scavenging assay (DPPH assay), and ferric reducing/antioxidant power (FRAP) assay. The extracts prepared ginger skin (TN-17) and coffee sediment (TN-16) showed strong activity. |