Effects of extraction time on total phenolic and flavonoid contents and antioxidant activities of a polyherbal drink

Abstract

Abstract The effect of extraction time on the color, total flavonoid content (TFC), total phenolic content (TPC), and antioxidant activity of the polyherbal drink consisted of 10% turmeric (Curcuma longa L.), 20% Java tea (Orthosiphon aristatus (Blume) Miq.), and 70% seed-under-leaf (Phyllanthus niruri L.) crude drugs were evaluated in this study. The drinks were prepared by decoction at various extraction times. The drink color was read by LAB colorimetry. TPC and TFC were determined by the official methods in the Indonesian Herbal Pharmacopeia (IHP). The antioxidant activity was evaluated by the standard 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The color of the extracts obtained from different extraction times was statistically equal in L*, a*, and b* of color parameters. The TPC, TFC, DPPH radical scavenging activity, and FRAP of the extracts were considerably increased during the first 15 mins of extraction. The TPC value started to decrease after being extracted for 45 mins. The value of TFC, DPPH radical scavenging activity, and FRAP of the drinks remained unchanged until the final extraction time. Thus, the recommended extraction time of the polyherbal drink was 15 mins to preserve the phenolic compounds and flavonoids and obtain optimum antioxidant activity.