VARIATION IN ANTIOXIDANT POTENTIAL OF CURCUMA LONGA L. COLLECTED FROM DIFFERENT ECOLOGICAL NICHES OF WESTERN HIMALAYAN REGION

Objective: The present study aims to evaluate the nutritional content and antioxidant activities of twenty accessions of turmeric rhizome from various locations of Uttarakhand. Methods: The antioxidant activity was evaluated by different method viz; DPPH radical scavenging activity, ferric reducing antioxidant power assay (FRAP), Hydroxyl radical scavenging activity, Nitric Oxide (NO) scavenging activity, Superoxide anion radical scavenging activity and nutritional value viz; total phenolic content, total flavonoid content, total ortho-dihydroxy phenols, total ascorbic acid content and total antioxidant capacity. Results: Alcoholic extracts of different turmeric rhizomes showed wide variation in abilities to scavenge nitric oxide, hydroxyl, superoxide free radical, DPPH with IC 50 values in the range of 39.03-76.14, 39.77-72.85, 43.77-77.13, 64.38-271.95 µg/ml and FRAP value 19.54-54.84 µmole. The total phenolic content, total flavonoid content, total ortho-dihydroxy phenols, total ascorbic acid content and total antioxidant capacity of different alcoholic extracts of rhizomes were found in the range of 11.19-51.49, 6.35-30.95, 0.93-8.12, 0.14-1.29 and 27.44-94.78 mg/g respectively. Conclusion: The alcoholic extract of different accessions of Curcuma longa L. has shown excellent biochemical and antioxidant potential and therefore refers as an important natural source of antioxidant.