Production of nixtamalized flour and tortillas from amarantin transgenic maize lime-cooked in a thermoplastic extruder

Effect of Pleurotus agaves mushroom addition on the physicochemical and sensory properties of blue maize tortillas produced with traditional and ecological nixtamalization

The physicochemical, nutritional and sensory properties of flours, doughs and tortillas made with traditional nixtamalization (TN) and ecological nixtamalization (EN) and enriched (9%) with the traditional maguey mushroom (Pleurotus agaves) were analysed. EN resulted in flours and tortillas having a greater content of bioactive compounds than that of TN flours, which represents a production process of maize tortillas containing high amounts of antioxidants. The addition of mushrooms to EN flours improved their sensory properties, whereas the addition of mushrooms to TN flours decreased them. The amount of P. agaves added to tortillas was equivalent to 3% enrichment with β-glucans. The edible mushroom P. agaves, highly appreciated in many Mexican regions, improved the nutritional and sensory quality of blue maize tortillas when added to flours prepared by EN. A new product was developed using local traditional foods of complementary nutritional value.

Emerging techniques assisting nixtamalization products and by-products processing: an overview

The production of worldwide nixtamalized products has increased in Latin American countries over the last years. For a better maize handling and exploitation of its nutritional elements, maize is subjected to a nixtamalization pretreatment protocol, which produces meaningful chemical, nutritional and quality changes in maize and its derived products, but large amounts of its primary by-product, well-known as 'nejayote', are also produced. Importantly, nejayote is usually discarded into the urbanized sewage with minimal treatment. Today, according to the recent research reports, new emerging techniques and protocols have been implemented to improve the nixtamalization products and by-products processing. New valorization approaches and biotechnological developments (including biotransformations) toward the reuse of nejayote have been developed according to its considerable content of biomolecules. Therefore, the goal of this paper is to provide a comprehensive review of the main development works at assisting nixtamalization products and by-products processing. Herein, particular attention is paid to experimental insights dealing with the valorization of nejayote.

Physicochemical, Rheological, and Morphological Characteristics of Products from Traditional and Extrusion Nixtamalization Processes and Their Relation to Starch

The aim of this study was to compare the physicochemical, rheological, and morphological characteristics of corn, nixtamalized flour, masa, and tortillas from the traditional nixtamalization process (TNP) and the extrusion nixtamalization process (ENP) and their relationship with starch. The traditional and extrusion processes were carried out using the same variety of corn. From both processes, samples of ground corn, nixtamalized flour, masa, and tortillas were obtained. The extrusion process produced corn flour with particle sizes smaller (particle size index, PSI = 51) than that of flour produced by the traditional nixtamalization process (PSI = 44). Masa from the TNP showed higher modulus of elasticity (G') and viscosity (G ″) values than that off masa from the ENP. Furthermore, in a temperature sweep test, masa from the TNP showed a peak in G' and G ″, while the masa from the ENP did not display these peaks. The ENP-produced tortillas had higher resistant starch contents and comparable firmness and rollability to those from the TNP but lower quality parameter values. A comparison of the products' physicochemical properties obtained by the two processes shows the importance of controlling the damage to starch during the milling and extrusion processes to obtain tortillas of better quality. For the first time, we propose the measurement of the viscoelastic parameters G' and G ″ in temperature sweep mode to monitor changes in the degree of starch damage.