Arabica and Conilon coffee flowers: Bioactive compounds and antioxidant capacity under different processes

Abstract

This study presents innovative research for comparison of the effect of the different dehydration techniques and methods of extraction on the antioxidant potential and bioactive compounds of Conilon and Arabica coffee flowers. The compounds were analyzed by high performance liquid chromatography and the antioxidant capacity evaluated by the 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide assays. Among the compounds evaluated, trigonelline, gallic acid, chlorogenic acid, and caffeine were identified, with trigonelline and caffeine being those with the highest concentration. The investigated factors significantly influenced the profile of the bioactive compounds identified, and the antioxidant capacity. The 92 °C infusion of freeze-dried Conilon coffee flowers, in general, showed greater antioxidant capacity by ABTS and DPPH assays, as well as total phenolic content. Lyophilization had a positive influence on maintaining the content of phenolic compounds and antioxidant capacity of the samples. Coffee flowers proved to be a potential raw material for making tea-like drinks.

Keywords: Caffeic acid (PubChem CID 689043); Caffeine; Caffeine (PubChem CID2519); Chlorogenic acid (PubChem CID1794427); Coffee; Ferulic acid (PubChem CID445858); Gallic acid (PubChem CID370); PCA; Phenolic compounds; Trigonelline; Trigonelline (PubChem CID5570); Vanillic acid (PubChem CID8468); p-cumaric acid (PubChem CID637542).