Total phenolics, flavonoids and antioxidant activity in thirty litchi genotypes of Eastern India

A good amount of phenolics have been found in fruit of litchi which shows diverse biological activities. The purpose of this present study was to evaluate phenolics and antioxidant activity in 30 different genotypes of litchi growing at National Active Germplasm Site, ICAR-NRC on Litchi, Muzaffarpur. The total phenolics (0.20 to 124.99 mg GAE/ g FW) and total flavonoids (0.50 to 96.37 mg Catechin/g FW) varied significantly among genotypes in different parts of plant. Total phenolics in thirty genotypes varied from 18.20 to 48.7 mg GAE/g, 46.10 to 107.30 mg GAE/g, 62.70 to 115.50 mg GAE/g, 19.82 to 124.99 mg GAE/g, 0.20 to 8.41 mg GAE/g, 8.57 to 61.24 mg GAE/g, 23.68 to 86.56 mg GAE/g, in inflorescence, flower bud, new and mature leaf, pulp, pericarp and seed, respectively. The total flavonoids contents in thirty genotypes ranged from 8.61 to 21.11 mg CAE/g, 17.26 to 46.79 mg CAE /g, 2.29 to 23.02 mg CAE /g, 8.15 to 26.55 mg CAE/g, 0.50 to 23.88 mg CAE/g, 0.75 to 96.49 mg CAE/g, 2.41 to 27.50 mg CAE/g in inflorescence, flower bud, new and mature leaf, pulp, pericarp and seed, respectively. A 32.3-fold difference in phenolics in pulp was found between highest and lowest genotypes, IC-0615586 and IC-0615600 (p < 0.05). A 7.14-fold difference in phenolic in pericarp was found between highest and lowest genotypes, IC-0615613 and IC-0615606 (p < 0.05). A 47.7-fold more difference in flavonoids in pulp was found between highest and lowest genotypes, IC-0615613 and Coll. 36 (p < 0.05). A 128.6-fold more difference in flavonoids in pericarp was found between highest and lowest genotypes, IC-0615610 and Coll. 37 (p < 0.05). Total antioxidant capacity in pulp varied from 3.39 to 7.8 mol TE/ g FW with highest in genotype IC-0615596 and lowest in genotype IC-0615600 and DPPH radical-scavenging activities varied from 25.63 to 73.15% with highest in genotype IC-0615593 and lowest in genotype IC-0615594. Similarly, total antioxidant capacity of pericarp varied from 6.35 to 10.28 mol TE/ g FW with highest in genotype IC-0615591 and lowest in IC-0615597 and DPPH radical-scavenging activity varied from 56.75 to 90.35% with highest in IC-0615585. A significant (p<0.01) positive relationship was found between antioxidant and total phenolics in pulp (r = 0.708) and total phenolics in pericarp (r = 0.571). Similarly, radicle scavenging activity of pulp was positively correlated with phenolics in pulp (r = 0.552) and antioxidant activity (r = 0.838) in pulp. This information on diverse accessions can help breeders select superior litchi varieties as well as in parental selection in crop improvement programmes.