Anthocyanin Profiling of Maize Grains Using DIESI-MSQD Reveals That Cyanidin-Based Derivatives Predominate in Purple Corn, whereas Pelargonidin-Based Molecules Occur in Red-Pink Varieties from Mexico

Corn seeds contain natural pigments
and antioxidants, such as the
molecular variants of flavonoids and carotenoids. The aleurone and
pericarp tissues from pigmented genotypes were extracted for metabolic
fingerprinting and evaluated using UV–vis and mass spectrometry
(MS). MS ionomic fingerprints classified samples according to genetic
background and kernel color. The MS/MS fragmentation pattern (Daughter
and Neutral Loss methods) allowed the tentative identification of
18 anthocyanins with glycosyl, malonyl, and succinyl moieties, including
535 m/z for cyanidin-3-O-(6″-malonyl-glucoside) and 621 m/z for cyanidin-3-O-(3″,6″-dimalonyl-glucoside).
We also detected 663 m/z for pelargonidin-3-O-(disuccinyl-glucoside) and 633 m/z for peonidin-3-O-(disuccinyl-glucoside).
Cyanidin-based anthocyanins were the most abundant in dark purple
colored kernels, while pelargonidins predominated in the red-pink
kernels of the “Elote occidental” landrace. Grains of “Conico negro” had a simultaneous pigmentation of aleurone and pericarp,
while Vitamaize had purple pigmentation only in the aleurone layer.
Most landraces had a white endosperm, while Vitamaize had a yellow
endosperm and a dark seed coat. We conclude that Vitamaize grains
contain both carotenes and anthocyanins, and therefore it is proposed
as a nontransgenic agronomically improved variety of tropical purple
maize, a good source for organic superfoods.