Is coffee powder extract a possible functional ingredient useful in food and nutraceutical industries?

Abstract

The present study aimed to assess the phytochemical content and in vitro bioactivity of ethanolic extracts of Arabica (A) and/or Robusta (R) coffee powder having different geographical origins. For this purpose, total phenols (TPC) and flavonoids (TFC) content as well as a- and b-tocopherol were quantified. The antioxidant activity was assessed by using a multi-target approach in which the radical scavenging potential, the protection from lipid peroxidation, and the involvement of the iron-reducing mechanism were applied. The carbohydrate hydrolyzing enzymes’ (a-amylase and a-glucosidase) inhibitory activities were also assessed. Arabica coffee sample (C2-A) showed the highest TPC, TFC, and a-tocopherol content with values of 63.1 mg chlorogenic acid equivalents (CAE)/g dry powder, 16.2 mg of quercetin (QE) equivalents/g dry powder, and 5.6 mg/100 g dry powder, respectively. Relative Antioxidant Capacity Index (RACI), used to statistically integrate results from 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing ability power (FRAP), and protection of lipid peroxidation assays, evidenced that sample C4-R derived from Robusta from Guatemala showed the highest antioxidant potential with a value of –0.61. Arabica from Puerto Rico was the most active against a-amylase, whereas the blend Arabica/Robusta sample (C5-A60R40) showed the highest inhibitory activity against a-glucosidase with IC50 values of 120.2 and 134.6 mg/mL, respectively. The results show how the qualitative-quantitative composition of the extracts is strongly associated not only with the variety but also with the geographical origin of the samples.