Physicochemical characterization of white, yellow and purple maize flours and rheological characterization of their doughs

Abstract

White, yellow and purple maize flours were obtained after dried kernels milling with two different sieves (200 and 500 μm). Hygroscopic characteristics, particle size distribution, colour and total starch and damaged starch (DS) of flours were determined. Maize flour doughs were obtained by mixing of flour and water in a laboratory kneader (Mixolab®) at constant dough consistency (1.10 ± 0.07 Nm). Dough properties like water absorption (WA), development and stability times were determined. Rheological characterization was carried out at 30°C by means of oscillatory frequency sweep (1-100 rad s −1 ) at 0.1 % strain and creep (50 Pa, 60 s) -recovery (0 Pa, 180 s) tests using a controlled stress rheometer. No significant differences were observed among water desorption isotherms of maize varieties and Halsey model was satisfactorily employed. Under the same milling conditions, white maize flours showed higher average particles size than purple and yellow maize flours. A model to predict flours colour involving colour parameters of the particle size fractions is proposed. Flours obtained with smaller particle size showed higher DS content and WA. For tested doughs, the mechanical spectra showed that elastic component was dominant over the viscous one. Damping factor varied slightly with angular frequency. Moduli values depended on average particle size and WA of dough. Creep-recovery data were satisfactorily fit with Burgers model. Instantaneous creep compliance varied with the same trend than elastic modulus. Viscoelastic creep compliance increased linearly with WA of the tested doughs and, at constant average flour particle size, increased with increasing DS.

Physicochemical, Thermal, and Sensory Properties of Blue Corn (Zea Mays L.)

“…The L * , a * , and b * values of blue corn kernels indicated that their color was on the blue and purple scale (Table ) and they were measured as 26.52, 5.74, and 1.60, respectively. In a study the L * , a * , and b * color values of purple corn flour were reported as 53.80, 2.22, and 2.54, respectively (Moreira and others ). While the L * and b * color values of blue corn flour were lower, the a * value was higher than the results of the reported studies.…”

“…Corn is not only consumed as a whole kernel by human and animals, but it also used to produce flour, starch, sugar syrups, and oil in the food industry. Other industry branches, such as chemistry, pharmaceuticals, and cosmetics, utilize corn for different purposes (Moreira and others ).…”

“…Chemical composition of corn can change depending on variety, climate, cultivation conditions, and harvesting periods. Therefore, there are different kinds of corn around the world, such as white, yellow, purple, red, and blue corn (Moreira and others ).…”

Setting Up Decision-Making Tools toward a Quality-Oriented Participatory Maize Breeding Program

“…Additionally, the market demand for gluten-free formulations has driven more research in the different steps leading from the maize kernel to the maize bread quality (e.g., Moreira et al, 2015 ; Garzón et al, 2017 ; Martínez and Gómez, 2017 ). In parallel, an increased investment on the improvement of open-pollinated maize populations has been driven by a renewed interest in materials traditionally used for ethnic food commodities and for their use in the context of more sustainable farming systems (e.g., Revilla et al, 2012 , 2015 ; Samayoa et al, 2016 ).…”

Modelling of the rheological behavior of mechanically dewatered sewage sludge in uniaxial cyclic compression

“…In rheology literature, it is also customary to consider the soecalled Burgers model, which consists of a Maxwell and a Kelvin materials in series (Malkin and Isayev, 2006;Morrison, 2001; Barnes et al, 1998). Indeed, this model is able to represent the rheological behavior of various materials as altered rock (Jiang et al, 2015), epoxy adhesive (Costa and Banos, 2015), asphalt mixture (Cai et al, 2013), thermoplastic polyurethane/organoclay nanocomposite (Ercan et al, 2017) or flour doughs (Moreira et al, 2015;Meerts et al, 2017). However, the Burgers model can require additional elements to represent a particular characteristic of the rheological behavior, as for instance an empirical expression for the stress hardening behavior of agar gels (Yu et al, 2012) or a plastic element for sandstone samples (Zhang et al, 2014).…”