Measuring antioxidant activity in yellow corn (Zea mays L.) inbreds from three different geographic regions

Corn (Zea mays L.) provides a major source of calories for human consumption and therefore, the nutritional components of corn have a large impact on human health. For example, corn kernels contain antioxidants, such as polyphenols (including anthocyanins and other flavonoids) and carotenoids. Such compounds represent useful targets for biofortification breeding. In this study, we used 34 corn inbred lines from three different regions (East Asia, Southern Asia, and subtropical regions) and 11 F1 hybrids derived from the inbreds to investigate antioxidant activity in yellow corn. We compared different methods for measuring antioxidant activity to test their consistency and to determine whether color could be used as an indicator of antioxidant activity. We also measured carotenoid levels in yellow corn. No difference in antioxidant activity was detected between inbred corn lines from temperate vs. tropical regions. We determined that carotenoid is a major contributor to antioxidant activity in yellow corn and that kernel color, especially yellowness, could be used as an indicator of antioxidant activity in yellow corn. These findings lay the foundation for the biofortification of yellow corn by providing information about the correlations among kernel color, carotenoid contents, and antioxidant activity and by identifying an easy method to assess antioxidant activity in yellow corn.