analysis of total phenol, flavonoid, and chlorogenic acid content of robusta coffee leaves extract using nades (natural deep eutectic solvent)

Robusta coffee (coffea canephora l.) is a widely traded tropical commodity recognized for alkaloids and flavonoids found in leaves, primarily identified as polyphenols. the use of natural deep eutectic solvent (nades) as a green solvent proves effective in extracting these compounds. therefore, this study aimed to determine total phenol, flavonoid, and chlorogenic acid content of robusta coffee leaves extract using 96% ethanol and nades. this study was carried out experimentally, including sample preparation, phytochemical screening, simplified extract characterization, nades formulation, testing physicochemical properties of nades, and preparing coffee leaves extract. nades had a 2:1 ratio of choline chloride to citric acid and a 1:1 ratio of choline chloride to lactic acid. simplified extract was extracted through maceration using a combination of 96% ethanol and nades, with varying extraction times of 15, 30, 45, 60, 120, and 240 minutes. phytochemical screening results showed the presence of alkaloids, flavonoids, tannins, saponins, glycosides, and triterpenoids/steroids. simplified extract composition included 6% water, 17.35% water-soluble essence, 8.06% ethanol-soluble essence, 7.95% total ash, and 0.76% acid-insoluble ash. in coffee leaves extract with nades2 (choline chloride:lactic acid) after 240 minutes, peak concentrations of total phenol (detected via the folin-ciocalteau method), total flavonoid (assessed with the alcl3 reagent), and chlorogenic acid were identified. the levels obtained were 29.42 mg gae/g extract for total phenol, 68.84 mg qe/g extract for total flavonoid, and 2.77 mg/g for chlorogenic acid at a concentration of 40.86. notably, nades exhibited superior extraction of total phenol and flavonoid compared to ethanol from coffee leaves.