Summary

The aim of this study was to recover the phenolic compounds from coffee industry residues and evaluate their antioxidant capacity. The residues (husk, pulp and spent coffee) were obtained from different steps of the industrial processing of coffee. The phenolic extracts were obtained using a mixture of acetone and water and the phenolic compound contents ranged between 72.88 and 159.50 mg GA g^–1 residue. Chlorogenic acid was detected and quantified in the coffee husk and pulp by high performance liquid chromatography (HPLC). The antioxidant capacity of the phenolic extracts was evaluated and they showed DPPH radical scavenging ability and reducing action against peroxyl radicals. The residue with the highest antioxidant capacity was the coffee husk. The results suggest the possibility of reusing the coffee industry residues to obtain antioxidant compounds, since these compounds have numerous applications in the food, cosmetic and pharmaceutical industries.

Key words:
Coffee residues; Phenolic compounds; Chlorogenic acid; DPPH free radical; Peroxyl radical