Antioxidant capacity and germination power of NaCl-elicited cowpea (Vigna unguiculata) sprouts with various NaCl concentrations and elicitation durations

Abstract

Cowpea (Vigna unguiculata) is one of legumes that have the potential as a source of food antioxidant related to the phenolic compounds. Germination can enhance the antioxidant capacity of cowpea and elicitation using NaCl within the germination process. It has been reported as an effective technique to improve the antioxidant potential of legumes sprouts. This study aimed to evaluate the antioxidant capacity (total phenolic content, DPPH radical scavenging activity, and reducing power (RP)) of NaCl-elicited cowpea sprouts with different concentrations of NaCl (50, 100, 150 mM) and elicitation durations (8, 12, 16 hours). The germination power of the NaCl-elicited cowpea was also investigated. Results showed that the total phenolic content, DPPH radical scavenging activity and RP of NaCl-elicited cowpea sprouts increase in line with the increase in NaCl concentrations and elicitation durations. Both DPPH radical scavenging activity and RP had significant correlation (p<0.01; r = 0.805; 0,785) with the total phenolic content. Nevertheless, germination power decreased along with increasing NaCl concentration and elicitation duration. The results of this study provide an alternative strategy for increasing the antioxidant capacity of cowpea through NaCl-elicitation. Thus, it can be a reference for developing cowpea-based functional food.