Suchergebnisse

The attention gained by cereals and derived products, such as tortillas, is due to their richness in phenolic and anthocyanin compounds. Although white maize tortillas have been a staple of the Mexican diet for centuries, blue maize has been adopted as a healthier alternative because of its important natural antioxidant source. The aim of the present work was to evaluate the involvement of colonic microbiota in the release of phenolic compounds with antioxidant activity present in traditional tortillas made from commercial white (WMT) and blue (BMT) maize flours. Nutritional composition in WMT and BMT exhibited no differences in protein (9.10 and 9.20%), ash (1.33 and 1.39%), energy (384.30 and 384.70 kcal), or phenolic consumption (323.44 and 437.33 mg/day) among tortillas. The highest anthocyanin (6.61 CGE/100 g), total phenolic contents (235.76 mg GAE/100 g), and antioxidant activity (5,992.14 and 1,651.64 µmol TE/100 g in ORAC and ABTS, respectively) were observed in BMT. Through microbiota fermentation, phenolic released content (13.4 mg GAE/g), ORAC (804.6 and 880.7 µmol TE/g), ABTS (27.4 and 30.7 µmol TE/g), and bioaccessibility (> 80%) displayed the highest values at 5 h. The present work demonstrated that colonic microbiota improved bioaccessibility of insoluble phenolics present in tortillas, favouring an antioxidant environment that positively impacts colonic health.

Germination improves seed functionality due to increased phytochemicals and associated antioxidant activities. These effects are enhanced with a suitable inductor which is applied at appropriate time and dose. The aim of the present work was to evaluate the effect of germination + UV-B elicitation on the chemical compositions, antioxidant activities (AoxA), total phenolic (TPC), total anthocyanin (TA), and γ-aminobutyric acid (GABA) contents in blue maize seeds. The application of UV-B radiation (wavelengths of 280 - 311 nm) during 37.0 h was an effective elicitor. Germinated-elicited blue maize flour (GEBMF) had higher proteins (+29.1%), dietary fibres (+22.0%), and AoxA (ABTS: +133.9%; DPPH: +173.4%) than unprocessed blue maize flour (UBMF). The increase in AoxA was closely related to the observed increase in TPC (+587.2%), TA (+29.9%), and GABA (+199.9%). Therefore, GEBMF could be used as a source of proteins, dietary fibres, and natural antioxidants in the formulation of new functional foods and beverages. These results could also contribute to the use and conservation of blue maize, an underutilised cereal.