Bioactive compounds and antioxidant activities in pigmented maize landraces

In Mexico, Central and South America, maize exhibits high diversity that is recognized phenotypically by color, grain shape and size, and cob and plant characteristics. The objective was to evaluate the effect of cropping location, accessions, and location-accession interaction on the phenolic compound contents and antioxidant activities in a collection of pigmented native maize from Oaxaca, Mexico. To accomplish this goal, 57 native maize accessions and three commercial varieties were planted and cultivated in the towns of San Agustín Amatengo and Santa María Coyotepec, Oaxaca, using a randomized complete block design with four replicates. The total anthocyanin, phenolic, and flavonoid contents were evaluated in samples of dry and ground grain, and DPPH and FRAP antioxidant activities were spectrophotometrically evaluated. The results showed significant differences (P≤0.05) between cropping lo cations, grain color groups, accessions within groups and locality-group and genotype-location interactions. The cropping location affected the total anthocyanins and phenolic contents and the antioxidant activities. The anthocyanin content in blue maize was higher than that in red maize. Significantly, decreasing differences were observed among the different grain colors (i.e., blue red>yellow in total phenolic, total flavonoids, and antioxidant activity), and significant interactions were observed between the localities and grain colors. High variability was observed between the accessions for bioactive compounds and antioxidant activities, and significant interactions were observed between locations and accessions of pigmented grains. Some accessions with remarkable composition and antioxidant activity were RJ02, RJ03, RJ04, RJ06, AZ10, AZ13, AZ16, and AZ18.