Purple-corn kernels
contain anthocyanins, a group of antioxidants proposed to be beneficial
to human health. This study investigated the concentrations of anthocyanins
and amino acids and the composition of fatty acids in the kernels
of purple waxy corn (Zea mays L.) “Heukjinjuchal”
during grain filling to determine when the grain nutritional value
is at its highest. During grain filling, anthocyanin contents increased
as the kernel color darkened. Among the anthocyanins measured, cyanidin-3-β-O-glucoside reached the highest contents, 57.0–409.1
mg kg–1 fresh weight in raw kernels and 1027.6 mg
kg–1 in dry seeds. Pelargonidin-3-β-O-glucoside and malvidin-3-β-O-glucoside
became detectable at 21 days after silking; they occurred in the second-
and third-highest amounts, respectively, among anthocyanins in the
purple-corn cultivars tested. The anthocyanin accumulation pattern
was strongly associated with physicochemical properties and partly
associated with amino acid content. Anthocyanin contents increased
in a stepwise rather than linear fashion. This study showed that kernels
undergo dramatic changes that affect the nutritional value of fresh
corn.