Effect of Temperature and Steeping Time on Calcium and Phosphorus Content in Nixtamalized Corn Flours Obtained by Traditional Nixtamalization Process

Corn starches were isolated using three different methods: water steeping, alkaline steeping, and acid steeping. The effects on their structural, micro structural, thermal, and chemical properties were evaluated, with especial emphasis in the alkaline process that is close related to the nixtamalization process. The isolation method influences the amylose content, crystallinity, and enthalpy of the starch granules. Scanning electron microscopy showed that the isolation method produced changes on the surface of the granules, and in some cases there were holes on the surface. Method 2 (the alkaline method) produces the starch granules with low protein and fat content and there was an increase in the enthalpy for this method, that can be explained in terms of thermodynamics by the increase of particles into the starch granules, which was confirmed by an increase in the ash content. A negative correlation between these variables was found (r ¼ 70.99), while a positive correlation between enthalpy and amylose content was also found (r ¼ 1).Keywords: corn starch; isolation method; functional properties of starch; amylose; amylopectin Almidones de maı´z fueron aislados por tres diferentes me´todos: usando reposo en agua, reposo alcalino y reposo a´cido. Se evaluaron los efectos de estos me´todos sobre las propiedades estructurales, microestructurales, te´rmicas y quı´micas en los gra´nulos de almido´n. Los resultados mostraron que los me´todos de obtencio´n de almido´n tienen fuerte influencia en el contenido de amilosa en los almidones aislados, ası´como en su estructura cristalina obtenida mediante difraccio´n de rayos X, ası´como cambios en la superficie de los gra´nulos observados por microscopia electro´nica de barrido, se tiene especial e´nfasis en el proceso alcalino, por que es cercano al proceso de nixtamalizacion. El me´todo alcalino produjo gra´nulos de almido´n con bajo contenido de proteı´na y grasa. En el caso del tratamiento alcalino, en te´rminos termodina´micos, el incremento en la entalpia tambie´n puede ser explicado por el incremento de las partı´culas dentro de los gra´nulos de almido´n, resultado que es confirmado por el incremento del contenido de cenizas. Finalmente, se encontro´una correlacio´n (r ¼ 70,99) tomando en cuenta los valores de cristalinidad y entalpia, y una correlacio´n positiva (r ¼ 1) entre entalpia y contenido de amilosa.Palabras clave: almido´n de maı´z; me´todo de aislamiento; propiedades funcionales de almido´n; amilosa; amilopectina

Section: X-ray Diffractionmentioning

confidence: 99%

Effect of the alkaline and acid treatments on the physicochemical properties of corn starch

Palacios-Fonseca

Castro-Rosas

Gómez‐Aldapa

et al. 2013

“…The sum of these components represented the total DF. The calcium content was estimated according the report of workgroup study (Ferna´ndez-Mun˜oz et al, 2004;Gutie´rrez et al, 2007;Rojas-Molina et al, 2009), considering an average of steeping time of 9 h, where the concentration of calcium in the corn pericarp was the 14.5 g/kg.…”

Section: Df Determinationmentioning

confidence: 99%

Effects of extrusion process in snacks of oats–nixtamalized corn pericarp mixtures on dietary fiber content and functional properties

Zambrano-Zaragoza

Gutiérrez-Cortez

Jiménez-Vieyra

et al. 2013

(2013) Effects of extrusion process in snacks of oats-nixtamalized corn pericarp mixtures on dietary fiber content and functional properties, CyTA -Journal of Food, 11:sup1, 38-45, DOI: 10.1080/19476337.2012 The aim this work was to establish the best conditions to increase the soluble dietary fiber (SDF), evaluate the effect of extrusion on the SDF, and insoluble dietary fiber (IDF), in a snack obtained by extrusion, that serve as a source of calcium and DF, using mixtures of oat-corn pericarp. The corn pericarp was obtained from byproduct of nixtamalization process which contains water, calcium hydroxide, soluble solids, and pericarp. The studied parameters were temperature (120-1408C), moisture (200-400 g/kg), and corn pericarp (200-400 g/kg); the responses were expansion ratio, SDF, IDF, and water absorption index (WAI). The R 2 were 4 0.85 for all factors. The best conditions were temperature (1338C), moisture (230 g/kg), and corn pericarp (300 g/kg), with responses of 93.1 g/kg increase in SDF, 60 g/kg decrease of IDF, expansion of 1.26, WAI of 4.12 g sediment/g dry solid, and calcium content 4350 mg/kg.

“…During nixtamalization, the cells walls of corn grains are solubilized; in consequence, some fractions of pericarp are removed. Subsequently, a portion of calcium remains is disposed in the supernatant called Nejayote (Rojas-Molina et al, 2009). …”

Section: Introductionmentioning

confidence: 99%

Physico-mechanic treatment of nixtamalization by-product (nejayote)

Valderrama-Bravo¹,

Gutiérrez-Cortez²,

Contreras-Padilla³

et al. 2013

Nejayote is a nixtamalization waste by-product, and for this reason, in this study, filtration cakes as well as filtrate nejayote were evaluated to select the filter medium and also to establish the operation conditions. The different media used as filters at constant pressure filtrations were polyester-cotton canvas, paper, and nylon. The filtrations showed that polyester-cotton canvas presents lower specific resistance of the cake at all pressure levels and dosages. Calcium content was less in filter medium nylon at pressure 98.10 kPa and dosage 1:0.25 nejayote/ diatomaceous earth. Regarding particle diameter, the nylon and paper filter media have the highest quality filtering at pressure of 63.77 kPa and dosage 1:0.25 nejayote/diatomaceous earth. Therefore, the filtration depends not only on the particle diameter of the solids, dosage and nejayote cake morphology, but that the filter media is also important in the selection of the operation conditions. Keywords: nejayote; filtration; dosage; filter media El nejayote es un subproducto contaminante de la nixtamalización, por lo que en este estudio se obtuvieron tortas de filtración y filtrados que fueron evaluados para seleccionar el medio filtrante y establecer condiciones de filtración. Los medios filtrantes empleados en la filtración a presión constante fueron: lona poliéster algodón, papel y nylon. Las filtraciones evidenciaron que la lona poliéster algodón presenta menor resistencia específica de la torta en todos los niveles de presión y dosificación. El contenido de calcio fue menor en el medio filtrante nylon a la presión 98,10 kPa y dosificación 1:0,25 nejayote/tierra diatomea. Respecto al diámetro de partícula los medios filtrantes nylon y papel dan una mayor calidad de filtrado a la presión 63,77 kPa y dosificación 1:0,25 nejayote/tierra diatomea. En consecuencia, la filtración no sólo depende del diámetro de partícula de los sólidos, dosificación y morfología de la torta de nejayote, también el medio filtrante es determinante en la selección de las condiciones de operación.