Anthocyanin accumulation, biosynthesis and antioxidant capacity of black sweet corn (Zea mays L.) during kernel development over two growing seasons

In this study, the content changes of anthocyanins levels, antioxidant activities as well as related genes in their biosynthesis pathways of two seasons black sweet corn kernels were determined. Generally, three anthocyanins contents showed similar trend with peak at 10 days after pollination (DAP) in both seasons existing as free forms, and they gradually grew afterwards as kernel matured. Pelargonidin as the leading component was decreased significantly in autumn comparing to contents in summer which may be affected by lower photosynthetically active radiation (PAR) and distinct gene expression levels. CF1, F3H and LAD as the essential genes in flavonoid and anthocyanin biosynthesis had high expression levels indicating higher production of flavonoid and anthocyanin. Black sweet corn (BSC) exhibited good in vitro and cellular antioxidant abilities compared to many fruits and vegetables indicating that BSC could be developed as a substitute food with high anthocyanin profiles and antioxidant capacity.