Analysis Quercetin of Green Coffee Beans (Coffea liberica) Extract Using Spectrophotometry UV-Vis

Abstract

Coffee is one of the most popular beverages in the world. coffee is one of the best sources of other bioactive compounds, such as flavonoids and phenolic acids. The aim of the present experiment was to determine qualitative and quantitative quercetine on green coffee beans (Coffea Liberica). Qualitative analysis was carried out using Thin Layer Chromatography (TLC) with the mobile phase chloroform:ethanol (24:1) producing Rf values 0,705 which were in accordance with the quercetin standard Rf 0,588. Confirmation of the presence of quercetin was strengthened by its characteristic greenish yellow fluorescence under 366 nm UV light. Quantitative analysis was carried out using UV-Vis spectrophotometry at a wavelength of 442 nm with quercetin as a standard. The results showed that the quercetin content in Liberica coffee bean extract was 0.263% ± 0.0042% extract, with a calibration curve linearity of r = 0.993 in the concentration range of 2-10 ppm. This research provides scientific information regarding the quercetin content in Liberian coffee which can be developed as a functional drink with antioxidant activity