Antioxidant potential of Indian eggplant: comparison among white, purple and green genotypes using chemometrics

Abstract

Twenty-six eggplant genotypes of different colours were evaluated for their variations in total phenolics, total flavonoids, total monomeric anthocyanin and antioxidant activity. Antioxidant potentiality was determined using two in vitro assays, viz. cupric ion reducing antioxidant capacity and 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Additionally, five colour attributes were evaluated. Among the eggplant genotypes, significant differences (p\ 0.05) were observed with respect to antioxidant composition and antioxidant activity. Total phenolics and total flavonoids varied from 13.00 to 49.29 mg/100 g fresh weight (FW) and 5.30 to 28.70 mg/100 g FW, respectively. Chemometric tools such as principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) were used to understand the possible classification of Indian eggplant genotypes based on their colour properties, antioxidant composition and antioxidant potentiality. PCA revealed that the first two components represented 80.68% of the total variability in the total variation. AHC classified genotypes into three main groups on the basis of the measured parameters. A white-coloured genotype was found to be the richer source of phenolics and flavonoids with high antioxidant activity.