Antioxidant activity and physico-chemical characterstics during development of Prosopis cineraria pods

Abstract: Prosopis cineraria commonly called ‘khejri’ is highly versatile tree supporting wildlife, human beings and livestock in Indian desert. It is used as food, fodder, fixes atmospheric nitrogen, stabilizes sand dunes and its fruits are consumed fresh as well as after drying. Pods were sampled at 5 developmental stages viz., S1(3.5 cm), S2 (5.7 cm), S3 (9.2 cm), S4 (15.3 cm), S5 (17.4 cm, naturally dried pods on tree) to evaluate the changes in phytonutrients(total sugars, reducing sugars, protein and total phenol) and antioxidant activity in terms of DPPH radical scavenging activity, nitric oxide scavenging and ferric reducing power assay during fruit development from S1 to S5. Total soluble sugar content increased from S1 stage (47.1 mg^-1f.wt.) to S5 stage (64.28 mg^-1f.wt.), reducing sugar and sucrose content also increased from 20.65 mg^-1f.wt to 29.45 mg^-1f.wt and 18.75 to 33.84 mg^-1f.wt, respectively. Free amino acid and protein content increased during the development of the pods from very young to ripened stage. Whereas, total phenol content (TPC) was high at S1 stage (229.59 mg^-1f.wt.) as compared to S5 stage (55.24 mg^-1 g.f.wt.) DPPH radical scavenging activity decreases from 78.46 to 22.72 % during fruit development but ferric reducing activity increased with maturity of the pods. These studies are significant in evaluating phytochemical and antioxidant activities of the fruits that are consumed in every season by the local rural people. This study can help in prioritization of these local underutilised fruits as they are rich in some of the phytonutrients and antioxidants.