Genotypic Variation in Anthocyanins, Phenolic Compounds, and Antioxidant Activity in Cob and Husk of Purple Field Corn

Abstract

Information on phytochemicals in the cob and husk of field corn is important for the use of corn waste in the production of value-added corn products. The objectives of this study were to evaluate the variation in monomeric anthocyanin content (MAC), total phenolic content (TPC), and antioxidant activity, as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) in 53 purple field corn genotypes, and to study the correlations of these traits with color parameters. Fifty-three corn genotypes were planted in a randomized complete block design with three replications in two locations in the dry season of 2015/2016. The effects of genotype, location, and the interaction between genotype and location were significant for most characters. Genotypic variation contributed to a large portion of the total variance for all traits, accounting for 63.9⁻86.9%. Corn genotypes were classified into six groups based on MAC, TPC, and antioxidant activity determined by the DPPH and the TEAC methods. The highest MAC, TPC, and antioxidant activity were obtained in TB/KND//PF3 and TB/KND//PF8 for husk, and only TB/KND//PF8 for cob. They should be used as parental lines to develop corn varieties with high phytochemicals. Chroma (C*) and hue (H°) of color parameters could potentially be used as an indirect selection criterion for improving MAC, TPC, and antioxidant activity in cob. The information is useful for the improvement of phytochemicals in cob and husk of field corn.

Keywords

• <i>Zea mays</i> L.
• maize
• germplasm
• diversity
• phytochemicals
• colorimeter
• pH-differential