Genotypic variability in anthocyanins, total phenolics, and antioxidant activity among diverse waxy corn germplasm

Abstract

Identification of germplasm sources of waxy corn (Zea mays L. var. ceratina) with high variability for anthocyanins, phenolic compounds, and antioxidant activity is an important phase for waxy corn breeding for improvement of useful phytochemicals. The objectives of this study were to evaluate 49 genotypes of waxy corn for color parameters, monomeric anthocyanin content (MAC) and total phenolic content (TPC), and antioxidant activities. The experiment was conducted under field conditions in a randomized complete block design with three replications for two seasons in the rainy and the dry season 2010. Corn genotypes and seasons were significantly different (P ≤ 0.01) for most traits under study except for TPC. Variations due to genotype were large for all characters, accounting for 74.43–95.70 % of total variations. The interactions between genotype and season were significant for all characters. Forty-nine corn genotypes were divided into four groups based on antioxidants and their activities. Significant and positive correlations were found among the anthocyanins, phenolics, and antioxidant activities, and correlation coefficients between anthocyanins with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability and Trolox equivalent antioxidant capacity (TEAC) assays were high (r = 0.94 and 0.88, respectively). All of the Hunterlab color parameters, including chroma and hue angle were highly correlated with anthocyanins, phenolics and their activities and therefore could be used as indirect selection criteria for improving levels of antioxidants and antioxidant activity in waxy corn.