Timing and Pattern of Anthocyanin Accumulation during Grain Filling in Purple Waxy Corn (Zea mays L.) Suggest Optimal Harvest Dates

Abstract

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.

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

“…Therefore, the a (green/red) and b (blue/yellow) color values of the kernels could be used as indicators of carotenoid contents and polyphenol contents, respectively. In purple waxy corn, kernel color is thought to reflect anthocyanin levels [16]. Lower correlation coefficients could be caused by the greater genetic diversity of the corn samples examined in this study.…”

“…The two hybrids between Korean inbred lines Shinwangok and Hwandaok are cultivars developed by the National Institute of Crop Science, Korea [14,15]. All kernel samples were harvested from corn grown in the field at the NICS, Suwon, Korea (37°15′47″N, 126°59′16″E) in 2019 with field preparation performed as previously described [16].…”

Nitrogen application impacts timing of nitrogen and anthocyanin biosynthesis in the kernels of purple waxy maize

“…Regarding harvest time, we found that the anthocyanin content in grains of purple waxy corn reached its maximum value at 20 DAP, but the accumulation amount of anthocyanins increased gradually and reached its maximum value at 31 DAP according to regression analysis. Kim et al (Kim et al 2020) reported that the anthocyanin accumulation in purple corn occurs largely during grain lling, and the anthocyanin content in waxy corn kernels increases continuously from 15 to 31 DAP, with a sharp increase at 24 and 29 DAP. This is different in our analysis results; the reason could be the selection of different varieties.…”

High phytosterol levels in corn cobs point to their sustainable use as a nutritional source

“…Increasing levels of stearic and oleic acids from 30 to 60 DAP in corn cobs coincided with decreases in palmitic acid levels. This observation is reasonable, since palmitic acid is elongated to stearic acid, which is then converted to oleic acid by stearoyl-CoA desaturase [32]. Linolenic acid levels in kernels are a determinant of the quality of corn oils [33].…”