Phytochemical characterization of eighteen colored corn varieties and coproducts from the 2022 season of the Missouri colored corn adaptation program

Colored corn varieties have been widely acknowledged for their relatively higher phytochemical contents entailing potential value-added applications. In this study, a continuation of the Missouri colored corn adaption program, eighteen colored corn varieties from the 2022 season were analyzed for dry milling characteristics and phytochemical contents using metabolomic, HPLC and spectrophotometric techniques. The mean pericarp yield for the varieties from 2022 was higher at 7.96 % (dry basis, db) compared to 4.65 % (db) for the varieties from 2020 and 2021. Six selected varieties were identified and further analyzed. The highest concentrations of total anthocyanins (TAC), phenolics (TPC), total flavonoids (TFC) and condensed tannins (CT) detected were 28.8 g cyanidin-3-glucoside (C3G)/kg, 53.1 g gallic acid (GA)/kg, 155.7 g epicatechin (EE)/kg and 13.7 g catechin (CT)/kg of pericarp, respectively. Overall, the mean of TAC, TPC, CT contents for the best five varieties from 2022 was greater at 20.6 g, 45.4 g, 138.2 g compared to 14.5 g of C3G, 27.7 g of GA, and 130.9 g of EE equivalent per kg of pericarp for the varieties from 2020 and 2021, respectively. Metabolomic analysis identified 43 distinct phytochemicals. Antioxidant potential was evaluated using four different assays, the mean antioxidant activities for the best five varieties from 2022 were higher. Histological analysis revealed the concentration of phytochemicals in pericarp, whose thickness ranged between 129.2 and 182.3 µm. The varieties from 2022 showed greater pericarp yield, higher concentrations of phytochemicals, and greater antioxidant potential compared to the previous year’s varieties, implying successful progression of the program. • Utilization of best varieties from previous breeding cycle for further adaptation. • Dry milling characteristics of 18 Midwest grown colored corn varieties in 2022. • Spectrophotometric, HPLC and UHPLC-MS analyses for phytochemical quantification. • Antioxidant assays revealed high biological activities of corn phytochemicals. • Greater phytochemical contents demonstrate successful progression of the program.