Antioxidant Activity of Aqueous Extracts of Roasted Bean Seeds of Coffea canephora Rubiaceae

Abstract

Phenolic compounds are highly solicited bioactive substances, present specifically in plants and playing a powerful antioxidant role. These secondary metabolites are endowed with several very interesting biological properties, which find applications in various fields, in particular in medicine, cosmetics and nutrition. Given the various virtues of these compounds, we were interested in determining by High Pressure Liquid Chromatography) HPLC their contents in the aqueous extract of roasted beans of Coffea canephora (EAGTCc) and particularly the contents of chlorogenic acid, caffeic acid and catechol. In addition, the antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH). Total polyphenols and total flavonoids were also assayed spectrophotometrically. HPLC showed levels of 3.7 % catechol, 5.4 % chlorogenic acid and 2.8 % caffeic acid in 100 g of dry matter of EAGTCc. The concentration of EAGTCc responsible for 50 % inhibition (IC50) of the DPPH radical is 75.54 ± 2.08 µg / mL. The contents of total polyphenols and total flavonoids are 81.67 mg EAG / g and 293.33 mg EQ / g. This antioxidant activity present in the EAGTCc is probably linked to the richness of the seeds of this plant in phenolic compounds. The results obtained are very interesting insofar as the use of natural compounds as antioxidants remains without side effects on the body and could replace the use of antioxidant molecules resulting from chemical synthesis.