Abstract

Cajanus cajan (L) Millsp., named Arhar in Hindi and Pigeon pea in English, is an important grain crop of rain-fed agriculture in semi-arid tropics, belonging to family Leguminosae. It is a food and a forage crop, rich in proteins with amino acids like methionine, lysine and tryptophan. Extensive studies on chemical composition of C. cajan have been done during last few decades. This article presents an overview of phytochemicals as a source of natural antioxidants in C. cajan seed extracts. The antioxidant potentials of the different fractions, that is, n-hexane, ethyl acetate, chloroform, methanol, n-butanol and aqueous, of C. cajan seeds were screened by using ABTS^∙+ assays, ferric reducing antioxidant power (FRAP) assay, total phenolic contents determination (TPC), total flavonoid contents (TFC) and metal chelating activity. Aqueous extract shows the highest trolox equivalent antioxidant capacity (TEAC) value, 140.69±0.34mM in ABTṠ⁺ assays and the highest total phenolic content (TPC) value, 927.5±0.8 gallic acid equivalent (GAE). Hexane soluble fraction showed the highest percentage of metal chelating activity, that is, 79.0±0.5% bound iron and the highest FRAP value 49.08±0.55 g/ml, whereas n-butanol soluble fraction indicated the highest total flavonoid contents as 1691.1±0.2 mg/g QE.

Key words: Leguminosae, Cajanus cajan, antioxidant potential, ABTS^̇+ assay, ferric reducing antioxidant power (FRAP) assay, total phenolic contents, total flavonoid contents, metal chelating activity.