Content and bioaccessibility of phenolic compounds in blue corn products and tortillas using traditional and ecological nixtamalization

Abstract

The purpose of this work is to study the effect of the traditional processing conditions of the corn (maize) tortilla on the content and bioaccessibility of total phenolic compounds (TPC). Corn tortillas are part of the staple diet in Mexico and previous work has been conducted on industrially-prepared tortillas, however, no research on the effect of traditional or industrial process conditions on the bioavailability of TPC has been reported. In addition, this study evaluates the effect of traditional preparation with Ca(OH)2 and the ecological method of nixtamalization (EN), which uses CaCl2, CaCO3 and CaSO4 for the process. Physical, bioactive properties in corn products (corn grain, nixtamalized corn and tortillas) and bioaccessibility in the oral, gastric, and intestinal phases were assessed using the CIELab, Folin-Ciocalteu and simulated digestion methods, respectively. Blue and purple colors were found to predominate in all products and nixtamalization released up to 64% more TPC than corn grain. A TPC retention of >92% was observed in tortillas prepared using the EN method with CaCl2, whereas traditional nixtamalization (TN) with Ca(OH)2 resulted in a 96% retention compared to that found in the grain. The corn tortilla is a valuable source of antioxidants because of the high (greater than 390%) bioaccessibility of TPC.