Improvement of nutritional and nutraceutical value of nixtamalized maize tortillas by addition of extruded chia flour

Abstract

In this work the objectives were: (1) To optimize the extrusion conditions of defatted chia seeds maximizing antioxidant activity (AoxA), total phenolic content (TPC) and in vitro protein digestibility (IVPD), and (2) To evaluate the nutritional, nutraceutical, and sensory (acceptability) properties of tortillas formulated with commercial nixtamalized maize flour (MASECAMR) and optimized extruded defatted chia flour. Response surface methodology was applied as an optimization tool. A central composite rotatable design with two factors [Extrusion temperature (ET=50-160°C), screw speed (SS=50-240 rpm)] in five levels were used. The extruded from each treatment (13) were dried and ground to obtain extruded defatted chia flours (EDCF). The desirability function was applied as optimization technique. The prediction models for each response variable were adequate and reproducible. The optimal extrusion conditions to obtain optimized extruded defatted chia flour (OEDCF) were ET=147°C/SS=237 rpm; a high global desirability (D=0.815) was associated with these optimal conditions. The tortillas elaborated with MASECATM flour + OEDCF had higher IVPD, C-PER, TPC and AoxA, and better antihypertensive potential than elaborated with only MASECATM flour. The addition of OEDCF to MASECATM flour increased the nutritional and nutraceutical value of the tortillas.