RESUMEN
This research aimed to evaluate the effect of different calcium compounds and their concentration on the viscoelastic parameters of flours and tortillas obtained with traditional and ecological nixtamalization. Specimens (tablets) of nixtamalized flours and tortillas (14% moisture) prepared with three different calcium sources and four concentrations were sintered using a die and a hydraulic press and were evaluated by stress-relaxation tests with a texturometer. Data collected from the stress-relaxation curve were fitted into a three-element generalized Maxwell model (r2 = 0.9999), allowing the detection of significant differences in the estimated viscoelastic parameters. When flours are processed into tortillas, the most notable change was the increase of +88.44% and +73.44%, respectively, in the summation of the elastic modulus, and the compressional viscosity in samples produced with CaCO3. On the contrary, tablets from samples with Ca(OH)2 presented a sharp diminishing (loss) in both of the evaluated viscoelastic parameters, accounting a decrease of -39.82% and -46.28% for the elastic modulus and compressional viscosity summations, respectively. Highly significant correlations were found among viscoelastic parameters when a slight proportional increase was observed in the specific elastic moduli, meaning that the energy was stored by each elastic element in the tablets, while the compressional viscosity coefficients varied as a function of time. Finally, it was found that the residual spring due to the pure elastic component (E0 ) stored energy during the entire test. PRACTICAL APPLICATION: There is no published information about a simple methodology for the evaluation of the viscoelastic properties of dry nixtamalized flours (powder) with a texturometer. The method proposed was sensitive and accurate, since it was capable of detecting differences among samples processed under distinct processing factors conditions. The study of viscoelastic properties of grain foods contributes to the construction of molecular theories occurring in their chemical compounds, which is strongly related to food texture. Those theories are handy to improve nutritional and textural properties of grain foods and are essential to powder handling, processing, and transportation, which allows the processing factors optimization.
Asunto(s)
Pan/análisis , Compuestos de Calcio/análisis , Harina/análisis , Elasticidad , Manipulación de Alimentos , Minerales/análisis , Comprimidos/química , Viscosidad , Zea mays/químicaRESUMEN
Nixtamalization is a well-known pre-treatment technique in the tortilla industry. Nixtamalized maize (nixtamal) is known for its modified physicochemical as well as nutritional attributes. In the present study, two types of nixtamalization processes (traditional and ecological) were employed for the development of whole-grain-maize-based noodles using Dent and Flint maize genotypes. Results showed that ecological nixtamalization had resulted in better cooking and textural qualities of noodles compared to the one prepared traditionally. Dent maize noodles from traditional and ecological nixtamalization had lower retention of phenolics (40 and 64%, respectively) whereas, Flint maize noodles retained 50 and 66% phenolics, respectively. Dent maize noodles had undergone phenolics loss of 5-6% on cooking while those of Flint maize lost only 2%. Ecological nixtamalization maintained the pH of the cooking liquor within an acidic-neutral range and yielded noodle with higher retention of phenolics whereas, the traditional process negatively affected the antioxidant compounds and their properties.
Asunto(s)
Antioxidantes/análisis , Culinaria/métodos , Harina/análisis , Manipulación de Alimentos/métodos , Fenoles/análisis , Zea mays , Zea mays/químicaRESUMEN
The traditional nixtamalization (TN) process, used for obtaining maize-based products, negatively affects bioactive compounds because of its highly alkaline pH. Recently, an ecological nixtamalization (EN) process has been developed that retains the pericarp and maintains the nejayote (wastewater) within the acidic-neutral range. This study examines the effect of pH on the nutraceutical compounds (NC) of maize, such as polyphenolics and anthocyanins (ANT), as well as the effect on the antioxidant capacity (AC). The highest concentration of total phenolics (TP) in the maize kernel was found in the black and yellow genotypes, the highest concentration of ANT in the black genotypes, and the highest concentration of AC in the red and white genotypes. In the flour, TP levels were between 206 to 400 mg GA/100 g, ANT levels were 141 to 4107 mg cyanidin-3 glucoside/kg, and AC levels were 2544 to 3001 mg AA/kg. In tortillas, TP levels were 255 to 319 mg GA/100 g, ANT levels were 32 to 3420 mg cyanidin-3 glucoside/kg, and AC levels were from 1513 to 2695 mg AA/kg. The reduced loss of soluble solids, the pH, and the formation of compounds with proteins and carbohydrates from the EN process positively affected NC retention.