Pigmented Corn Varieties as Functional Ingredients for Gluten-Free Products

Abstract

Oxidative stress, one among the several factors responsible for the gluten toxicity in celiac disease, together with inflammation and duodenal mucosal injury, are only partially reduced by the gluten-free diet. Thanks to their phenolic profile, the pigmented varieties of corn could be an interesting source of dietary antioxidants for the formulation of new gluten-free ingredients. The aim of this research was: (1) to characterize the phenolic profile and the associated antioxidant properties of corn samples with different pigmentation, using spectrophotometric and chromatographic techniques and (2) to assess the stability of anthocyanins during the gastro-intestinal digestion. The pigmented varieties showed a significantly higher content of polyphenols compared to the common yellow varieties and, as a consequence, a higher antioxidant activity. Although corn is among the cereals most frequently used in gluten-free products, it can produce an inflammatory response in some celiac patients. Therefore, after the chemical characterization, the safety of the pigmented varieties for celiac patients was confirmed using different in vitro models (cell agglutination test and the measure of transepithelial electrical resistance). Although in vivo studies are necessary, the data collected in this study underline that the pigmented corn could have a role in reducing the oxidative stress at the intestinal level in celiac subjects.

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

“…Therefore, after chemical characterization, the safety of pigmented varieties for patients with gluten intolerance was confirmed by different in vitro models (a cell agglutination test and measurement of transepithelial electrical resistance). Although in vivo studies are necessary, the data collected in the aforementioned study underline that pigmented corn could play a role in reducing oxidative stress at the intestinal level [ 59 ]. Cellular assays applied in another study confirmed the absence of alterations by pigmented strains in the permeability of the cell monolayer, a key step in the mucosal inflammatory cascade in various intestinal disorders [ 60 ].…”

Does Plant Breeding for Antioxidant-Rich Foods Have an Impact on Human Health?

“…Maize is naturally rich in antioxidants and pigmented varieties of corn could be used as healthy ingredients for the formulation of novel gluten-free products [91]. The antioxidant activity of maize flour is dependent on phenolics, mainly ferulic acid, carotenoids, phlobaphenes, and anthocyanins, which confer different colours to five types of corn (white, yellow, blue, purple, and red).…”

“…An alternative source of anthocyanins suitable for the development of dietary supplements is the purple corn cob with a concentration range of 3.1 to 12.6 mg of cyanidin-3-glucoside equivalents/g [79,80]. Finally, red pigmentation depends on the MYB P1 gene, which activates phlobaphene accumulation (27.53 mg/g) in pericarp of maize seeds [91]. Yellow corn varieties contain lutein, zeaxanthin, β-cryptoxanthin, and β-carotenes mainly in the germ, followed by aleurone and endosperm [68,93,94].…”

Phenolic Profile and In Vitro Antioxidant Activity of Different Corn and Rice Varieties

“…Corn and rice are among the most frequently consumed cereals in GFD; their pigmented varieties could be used as innovative ingredients to improve the quality of the celiac diet [ 10 ].…”