Evaluación de dos procedimientos de medición de color en granos de maíces pigmentados

Abstract

El grano de maíz con pigmentos tipo antociano, no presenta una coloración homogénea en su superficie, por lo que la forma de presentar el grano para tomar la lectura de color afecta los resultados. En este trabajo se compararon dos formas de tomar la lectura de color en muestras de grano de colores diversos. Se emplearon muestras de grano de color azul morado (AZM), rojo cereza (RC), rojo ladrillo (RL), amarillo (AM) y blanco (BCO), este último como testigo. Los dos procedimientos para medir la coloración del grano fueron: montado sobre una base de plastilina, simulando como se encuentra en la mazorca (GMP) y grano en charola (GCH). El color se determinó con un colorímetro Hunter-Lab Mini Scan. En los colores de grano AZM, RC y RL el procedimiento para tomar la lectura de color afectó las variables de color. En los maíces AZM, las diferencias se presentaron tanto en la luminosidad, como en hue y croma, en los RC y RL fue la variable hue la más afectada. En los maíces de grano AM y BCO, los valores de luminosidad, hue y croma fueron numéricamente cercanos entre las dos formas de tomar la lectura de color en el grano. De acuerdo con los resultados, en los maíces AZM, RC y RL el color debería tomarse en el GMP, para obtener valores en las variables de color, que se relacionan con la apreciación visual de color, en tanto que en los maíces de grano AM y BCO el procedimiento para tomar la lectura, si bien afecta las variables de color, el valor de hue corresponde con la apreciación visual del color.

Bioactive Compounds from Pigmented Corn (Zea mays L.) and Their Effect on Health

“…Pigmented maize is appreciated in the producing communities and is used to prepare traditional dishes; however, it is at risk of disappearing due to the decrease in the cultivation area, its limited use and its low demand as a raw material for corn mills. In view of this, strategies are being sought to conserve them, promote their planting and increase their production in the field [ 3 ].…”

“…Pigmented corns contain anthocyanins in different ranges, depending on the breed and variety, which give them colorful colors, as well as carotenoid compounds (carotenes and xanthophylls). These phytochemical compounds give pigmented corn a nutraceutical advantage over white and even yellow corn, despite the latter’s high carotenoid content [ 3 ]. Anthocyanins can be found in the pericarp and aleurone, or only in one of them.…”

“…Pigments have also been observed in its endosperm [ 9 ]. The location of the pigments is of great importance because it is an indication of the amount of pigments that can be extracted and allows one to decide on the best way to use these compounds without degrading them [ 3 ]. Other groups of compounds found in pigmented corn, although in smaller quantities, are free phenols, non-anthocyanidic flavonoids, ferulic acid, lutein, zeaxanthin, cryptoxanthin, alpha and beta carotenes, among others.…”

Bioactive Compounds from Pigmented Corn (<em>Zea mays</em> L.) and Their Effect on Health

“…Pigmented maize is appreciated in the producing communities and is used to prepare traditional dishes; however, it is at risk of disappearing due to the decrease in cultivation area, its limited use and low demand as a raw material for corn mills. In view of this, strategies are being sought to conserve them, promote their planting and increase their production in the field 2 .…”

“…Pigmented corns contain anthocyanins in different ranges, depending on the breed and variety, which give them colorful colors, as well as carotenoid compounds (carotenes and xanthophylls). These phytochemical compounds give pigmented corn a nutraceutical advantage over white and even yellow corn, despite the latter's high carotenoid content 2 . Anthocyanins can be found in the pericarp and aleurone, or only in one of them.…”