Phase II-Inducing, Polyphenols Content and Antioxidant Capacity of Corn (Zea mays L.) from Phenotypes of White, Blue, Red and Purple Colors Processed into Masa and Tortillas

Abstract

White, blue, red and purple corns (Zea mays L.) were lime-cooked to obtain masa for tortillas. The total phenolics and anthocyanins content, antioxidant activity expressed as total reducing power (TRP), peroxyl radical bleaching (PRAC), total antioxidant activity (TAA) and quinone reductase (QR) induction in the murine hepatoma (Hepa 1 c1c7 cell line) as a biological marker for phase II detoxification enzymes were investigated. Among the extracts prepared from raw corn varieties the highest concentration of total phenolics, anthocyanins, antioxidant index and induction of QR-inducing activity were found in the Veracruz 42 (Ver 42) genotype. The nixtamalization process (masa) reduced total phenolics, anthocyanins and antioxidant activities and the ability for QR induction when was compared to raw grain. Processing masa into tortillas also negatively affected total phenolics, anthocyanin concentration, antioxidant activities, and QR induction in the colored corn varieties. The blue variety and its corresponding masa and tortillas did not induce QR. Ver 42 genotype and their products (masa and tortilla) showed the greatest antioxidant activity and capacity to induce QR.

Effect of different calcium sources on the bioactive compounds stability of extruded and nixtamalized blue maize flours

“…These two factors synergistically contribute to anthocyanins loss. Additionally, it should be noted that anthocyanins are located mainly in pericarp and aleurone layer of the grain (Urías-Peraldí et al 2013) and that most of these parts of the grain are degraded during nixtamalization (Salinas-Moreno et al 2003) and leached into the nejayote (Cortés-Gómez et al 2006;López-Martínez et al 2011). Some investigations reported anthocyanins losses of 55.…”

“…EFs prepared with both calcium sources and without calcium showed higher retention of polyphenols (61.7-87.5 %) and antioxidant activity (65.1-87.2 %) than . These losses can be attributed to combined effect of alkalinity and temperature during nixtamalization process, as well as physical losses of pericarp and bioactive compounds including the phenolic compounds leaching into the nejayote (Del Pozo-Insfran et al 2007;López-Martínez et al 2011). The phenolic compounds, which are bound to hemicellulose in the cell wall of pericarp, aleurone layer and kernels germ (Adom et al 2005;De la Parra et al 2007;Mora-Rochín et al 2010) are hydrolyzed and released into the cooking liquid during thermalalkaline treatment.…”

“…Instant corn flour is used to make tortillas and derivative products (Ruiz-Gutiérrez et al 2012). However, the nixtamalization of pigmented maize has the disadvantage that the bioactive compounds, like the anthocyanins are degraded in the alkaline pH of the cooking solution (Salinas-Moreno et al 2003;Del Pozo-Insfran et al 2007) and at the same time free phenolic compounds are released from the pericarp into the cooking solution (Cortés-Gómez et al 2006;López-Martínez et al 2011). The alkaline medium provokes some chemical changes in the molecular structure of the anthocyanins resulting in color changes (Salinas-Moreno et al 2003;Cortés-Gómez et al 2006), additionally, nejayote discharges generates environmental pollution problems.…”

Effect of different calcium sources on the antioxidant stability of tortilla chips from extruded and nixtamalized blue corn (Zea mays L.) flours

“…This could be attributed to the short-time thermal extrusion that minimized the damage in the total phenolic content in the flour (Mora-Rochín et al, 2010), whereas the nixtamalization process caused physical loss of the pericarp and leaching of phenolics into the cooking liquor (Del Pozo-Insfran et al, 2007;Pflugfelder et al, 1988;López-Martínez et al, 2011), resulting in lower phenolic content in NF. All TCEF showed significantly higher phenolic content than that of TCNF.…”

“…This may also due to the small variation in the pH (pH 5.66) of the flour with C 6 H 10 O 6 Ca and the pH (6.57) of the flour with Ca(OH) 2 ), which resulted in greater retention of antioxidant activity in TC. During nixtamalization, some of these compounds are lost by the severity of thermal-alkaline process and by the leaching of these same compounds to the nejayote, causing a decrease in the antioxidant content (Del Pozo-Insfran et al, 2007;López-Martínez et al, 2011) and therefore a decrease in the antioxidant activity of the flours and TCNF, which showed a significant reduction of 60% of NF, on average. Correlation analysis between the values of the bioactive compounds, phenolics, and anthocyanins and the antioxidant activity and color of tortilla chips was performed for the different treatments ( Table 2).…”