RESUMO
Waxy corn kernels with different colors have high phenolic content and good application potential in medicine and food healthcare. In our work, the content changes of phenolic and anthocyanins profiles were related to genes in the anthocyanin biosynthesis pathway, and the antioxidant activities of three different colors of waxy corn kernels (black, white, and yellow) were determined during kernel development. Results showed that growing temperature and light intensity could affect the accumulation of phytochemicals and antioxidant activities in waxy corns during maturation. Phenolic and antioxidant activities decreased over kernel maturation, and spring had higher nutrition levels during the best harvest time (20 and 25 days after pollination in the spring and autumn, respectively) for waxy corns. Cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside were the main anthocyanins detected in the black waxy corns. The contents of cyanidin are higher than pelargonidin followed by peonidin in the autumn, while on the other hand, pelargonidin had a slightly higher content compared to cyanidin in the spring. DFR, CF1, and ANS were the key genes affecting anthocyanin accumulation. This work provided information on the best harvest time for the pigment of waxy corn in order to achieve relatively high phenolic profiles and antioxidant activities. It also illustrated the possible relationship between weather conditions, gene expression levels, and phenolic content during kernel development.
