Effect of simulated gastrointestinal digestion on the phenolic compound content and in vitro antioxidant capacity of processed Cowpea (V. unguiculata) cultivars

Abstract

The aim of this study was to analyze the phenolic content and antioxidant activity of five cowpea cultivars after processing and in vitro digestion. Raw cowpea samples showed a significant decrease in total phenolic content (TPC) when compared with the processed samples, however an increase was subsequently observed in digested samples. The antioxidant activity determined using, DPPH, ABTS, ferric reducing antioxidant power (FRAP) assay, and total peroxyl radical-trapping antioxidant parameter showed a similar trend to the phenolic content with a significant decrease in activity upon processing and an increase after digestion. In conclusion, all cowpea cultivars showed a high TPC content as well as an increased antioxidant activity after digestion indicating the potential health benefits which cowpea could provide to consumers. Therefore, this study shows that in vitro digestion improves the digestion and absorption of beneficial components of processed cowpea at the intestinal level.

Keywords

• Simulated gastric digestion
• FRAP
• DPPH
• TRAP
• Cowpea