Effect of nixtamalization extrusion conditions in purple creole corn (Zea mays L.) from the state of Guerrero on nutraceutical and functional properties of the optimized corn flour

Abstract In Mexico, pigmented creole corn varieties are used for its consumption in a great diversity of foods. Purple corn has a high content of phytochemicals (health promoters). The extrusion process improved the accessibility of these phytochemicals. The aim of this work was to evaluate the effect of extrusion factors on the nutraceutical and functional properties of nixtamalized purple corn flour, and determine the optimal process conditions that allows obtaining a flour with the best characteristics to be used in the preparation of a beverage. The processing factors were temperature (T = 50-170 °C) and screw speed (SS = 50-240 rpm). The properties evaluated were total phenolic compounds (TPC), total anthocyanins (TA) antioxidant activity (AOX), and water solubility index (WSI). The optimization was carried out using the response surface methodology. The optimization yielded the following values: AOX: 676.34 µmol ET/100 g, TPC: 299.61 mg EGA/100 g, TA: 29.9 mg EC3G/100 g and WSI: 6.31%, under process conditions T = 50 °C and SS = 50 rpm. It was demonstrated that it is possible to generate a flour with the use of pigmented corn native to the state of Guerrero, with suitable properties for developed new corn based products.