Effect of nixtamalization on morphological and rheological characteristics of maize starch

Nixtamalization of maize grain is an ancient process that until now is used for tortilla production. This thermal-alkaline process produces important changes in morphology and rheological characteristics of starch that is the major component of maize. The aim of this study was to evaluate changes in the morphological and rheological properties of starch brought by nixtamalization of maize using image analysis and dynamic rheometry, respectively. Nixtamalized maize starch (NS) presented granule sizes higher than starch isolated from raw maize (S) due to the partial swelling produced in the nixtamalization process. In dynamic tests during the retrogradation kinetics, an inverse effect of the temperature was observed in the re-arrangement of starch components. NS was affected due to the thermal-alkaline process presenting an annealing that provoked a reduction in its ability to develop gels. This information is important during the processing of nixtamalized maize to masa and tortilla production.