Extraction and determination of total polyphenols and antioxidant capacity of red coffee (Coffea arabica L.) pulp of wet processing plants

Abstract

Background

Coffee waste disposal from wet processing units is increasing with an increase in coffee consumption throughout the world. This not only has a limitation in terms of environmental pollution, but also high waste volume is an opportunity to extract essential bioactive compounds and antioxidants for food and pharmaceutical industries. The aim of this paper was to investigate the effects of extraction solvents and coffee cherry pulps of different varieties in terms of their yield potential for total polyphenols and antioxidant capacity.

Results

Results show that coffee cherry pulps from different varieties extracted by different solvents showed significant effects. Among the studied varieties, coffee cherry pulp from Ababuna variety was found to be superior in total polyphenols (1809.9 mgGAE/gm) content and antioxidant capacity (70 % inhibition). This value was followed by pulp from the Dessu variety. But the pulp from variety 741, extracted using aqueous ethanol solvent, showed inferior results for both total polyphenol content and antioxidant capacity. Among the solvents studied in this work, aqueous methanol responded better for pulps of all varieties except Dessu which responded better for aqueous acetone solvent.

Conclusions

Red coffee cherry pulp discarded as a waste from wet coffee-processing plants can be used as a raw material to extract important value-added products like polyphenols and other antioxidants. These compounds can be used as biological additives in food and pharmaceutical industries to fight chronic diseases and aging. Furthermore, the study shows the possibility of extracting value-added bioactive compounds from biological wastes.[Figure not available: see fulltext.]