Nutraceutical content and free radical scavenging capacity of brinjal (Solanum melongena L.) genotypes

Abstract The present study compared the nutraceuticals in thirty different genotypes of brinjal, cultivated in the Punjab state of India. Activity of enzyme polyphenol oxidase was studied in selected genotypes of brinjal in correlation with the phenolic compounds. The free radical scavenging capacities were evaluated by three assays viz. 2,2′-azinobis (3-ethylbenzothiazoline-6 sulfonic acid) (ABTS); 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). Study showed wide variation in content of phenolic compounds (total phenols, flavonols, ortho-dihydroxyphenols, quinones and tannins) in different brinjal genotypes. Polyphenol oxidase (PPO) activity was higher in P-71 and SR-305 with different substrates, catechol and caffeic acid respectively. PPO activity had positive correlation with quinone content whereas negatively correlated with phenols. SR-301 genotype had maximum free radical scavenging capacity as studied by different assays: ABTS assay (92.21 ± 2.15 EC 50 , μg ml −1 ), DPPH assay (124.58 ± 4.55 EC 50 , μg ml −1 ) and FRAP assay (29.92 ± 1.64 μmol TE g −1 ). The results indicated perspectives for the usage of selected brinjal genotypes with considerable level of nutraceuticals and radical scavenging activity.