Comparative analysis of phenolic compounds and biological activities of four varieties of Coffea arabica L.

Document Type : Research Paper

Authors

Department of Biology, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran

10.22034/jppb.2023.56453.1305

Abstract

Coffee consumption has been growing globally due to its appreciated taste and its beneficial effects on health. In the present study, the content of phenolic compounds and biological activity of four varieties of Coffea arabica L. (Heirloom 1-4) from the flora of Africa were investigated. Ethanolic extracts of the green and roasted coffee beans were screened in vitro for their total phenol and flavonoid contents using Folin-Ciocalteu and AlCl3 assays, respectively. Also, the antioxidant activity of the extracts was evaluated by three complementary test systems, namely DPPH free radical-scavenging, metal chelating activity, and β-carotene/linoleic acid. The antibacterial activity of the aqueous extracts of the samples against two gram-positive and two gram-negative bacteria was also studied by the disk diffusion method. Results showed that the ethanolic extracts from both green and roasted beans of the variety Heirloom 4 contain the highest amounts of phenols and flavonoids. In addition, results from antioxidant activity assays showed that the studied extracts were less active than ascorbic acid as a standard synthetic antioxidant in the DPPH radical scavenging assay and also in the metal-chelating activity. However, in the β-carotene/linoleic acid system, oxidation of linoleic acid was effectively inhibited by all studied extracts. Furthermore, the aqueous extracts of the green and roasted beans of all varieties showed proper antibacterial activity against the bacterial strains tested.

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