Mechanical Properties in Wheat (Triticum aestivum) Kernels Evaluated by Compression Tests: A Review

To assess the quality of food grains, it is necessary to consider the following two aspects: their general characteristics and their intrinsic quality. Analyzing the quality of wheat kernels is complex due to the particularity of wheat proteins and the diversity of products that can be developed. In contrast, basic factors are used to assess quality aspects, with a focus on kernel hardness. This parameter is usually measured by the force that is required to make the grain rupture. The application of force must be controlled, and hence, the grain will exhibit other mechanical attributes and behavioral characteristics that can be used to evaluate it more objectively. This has led to the development of nondestructive evaluation methods based on the mechanical properties of kernels. This review carried out research on grain wheat, in which the main objective was to evaluate mechanical properties, including the viscoelasticity of the wheat kernels, by using compression tests. The study examined different methods of applying those techniques and the parameters they evaluated. Finally, the results obtained by the different investigation groups that applied the compression tests on wheat kernels were discussed

Influencia del gatuño (Mimosa monancistra benth.) en la infiltración de agua y la cantidad de forraje en pastizales con diferente grado de disturbio en el altiplano central mexicano

Observations were made during 2002 and 2004 in the states of Aguascalientes and Jalisco, México, aiming at evaluating catclaw mimosa´s influence on the amount of herbaceous biomass, total water infiltration and infiltration depth in the soil profile, on three sites and two influence areas (inside and outside) catclaw mimosa´s canopies. The amount of herbaceous biomass in site I was different 264.7 g/m2 and 186.5 g/m2 obtained inside and outside catclaw mimosa´s canopies respectively, as influenced by the interaction site X influence area (PLas observaciones se realizaron en el periodo comprendido entre el año 2002 y el 2004 en los estados de Aguascalientes y Jalisco, México, con los objetivos de evaluar la influencia del gatuño en la cantidad de biomasa herbácea, la infiltración total de agua y la profundidad de infiltración en el perfil del suelo, en tres sitios y dos áreas de influencia (dentro y fuera) del dosel de gatuño. La cantidad de biomasa en el sitio I resultó diferente (

Influencia del gatuño (Mimosa monancistra benth.) en la infiltración de agua y la cantidad de forraje en pastizales con diferente grado de disturbio en el altiplano central mexicano

Las observaciones se realizaron en el periodo comprendido entre el año 2002 y el 2004 en los estados de Aguascalientes y Jalisco, México, con los objetivos de evaluar la influencia del gatuño en la cantidad de biomasa herbácea, la infiltración total de agua y la profundidad de infiltración en el perfil del suelo, en tres sitios y dos áreas de influencia (dentro y fuera) del dosel de gatuño. La cantidad de biomasa en el sitio I resultó diferente (P¡Ü0.01), con un total de 264.7 y 186.5 g/m2 fuera y dentro del dosel de gatuño respectivamente, como respuesta de la interacción sitio y área de influencia, no resultando así en los sitios II y III donde no existieron diferencias. La infiltración total de agua fue evaluada a los 15, 60 y 105 min y resultó afectada por la interacción sitio X área de influencia solamente a los 60 y 105 min. En el sitio III, a los 60 min este parámetro fue diferente (P¡Ü0.01) entre áreas de influencia, con un total de 110.7 mm dentro y 78.1 mm fuera del dosel de gatuño, no así en los sitios I y II donde no existieron diferencias entre áreas de influencia. A los 105 min se detectaron diferencias (P¡Ü0.01) entre áreas de influencia en los tres sitios. La profundidad de infiltración en el perfil del suelo estuvo afectada por la interacción sitio X área de influencia, detectándose que esta variable en los tres sitios resultó distinta en las dos áreas de influencia (P¡Ü0.01)

Quality evaluation of tortilla chips made with corn meal dough and cooked bean flour

A mixture of cornmeal dough and cooked bean flour (BF) was prepared at different ratios (50/50, 60/40, and 70/30 w/w), and processed to chips. Viscosity profile, temperature of gelatinization and enthalpy, texture, protein content, and in vitro digestibility were measured. Pasting temperature tended to be lower when the flour bean concentration was lower. Maximum viscosity increased significantly in both samples (dough mixture and chips) when the BF concentration was lower. In general, gelatinization temperature remains constant, while the heating enthalpy was higher with lower BF concentration. The addition of BF was correlated with greater crispiness, suggesting improved chip texture at higher BF concentrations. The final protein content in the corn-bean chips was very similar, despite the concentration of BF used. Protein digestibility in the chips was affected by the proportion of BF added, being higher when the amount of the BF was lower

Specific Anthocyanin Contents of Whole Blue Maize Second-Generation Snacks: An Evaluation Using Response Surface Methodology and Lime Cooking Extrusion

Lime cooking extrusion (LCE) is a widely applied technology for producing second-generation snacks, as an alternative to traditional nixtamalization (TN). Pigmented maize has been used to produce snacks with similar organoleptic characteristics to TN products and to obtain a product with additional functional benefits due to the anthocyanic compounds contained in those grains. However, during the process, anthocyanins are degraded, and several chemical modifications occur. Response surface methodology is applied to evaluate extrusion factors and their effects on the response variables of extrudates. The aim of this study was to evaluate the changes in specific anthocyanins after extrusion in second-generation blue maize snacks. Three anthocyanins were identified and quantified by HPLC-UV-DAD: cyanidin 3-glucoside and pelargonidin 3-glucoside, which have been previously reported in blue maize and its products, and cyanidin 3,5-diglucoside. Higher retention values were found in the extrudates making LCE a viable option for producing second-generation blue maize snacks

Exploiting the Native Microorganisms from Different Food Matrices to Formulate Starter Cultures for Sourdough Bread Production

International audienceThe use of sourdough for bread production involves fermentation, which is dominated by lactic acid bacteria (LAB) and yeast. Sourdough can be inoculated with a starter culture or through a food matrix containing microorganisms to initiate sourdough fermentation. Sourdough is used as leavening agent for bread making, and metabolites produced by LAB and yeast confer a specific aroma and flavor profile to bread, thus improving its sensory attributes. However, few publications report the effect of microorganisms from different food products and by-products on sourdough fermentation. This review focuses on using different starter cultures from various food sources, from wheat flour to starter cultures. Additionally, included are the types of sourdough, the sourdough fermentation process, and the biochemical transformations that take place during the sourdough fermentation process

Biophysical, Nutraceutical, and Technofunctional Features of Specialty Cereals: Pigmented Popcorn and Sorghum

Different pigmented corn and sorghum types were evaluated to characterize their biophysical, nutraceutical, and technofunctional properties for the first time. Commercially pigmented (blue, purple, red, black, and yellow) popcorn (Zea mays var. everta) and sorghum (Sorghum bicolor L.) of yellow and red colors were analyzed. Biophysical and proximal analyses were performed using official methods. The nutraceutical profile included the total phenolic and anthocyanin content. In addition, rheological, structural, and morphological studies were conducted. The results demonstrated significant differences between the popcorn samples and grain types, especially in terms of their biophysical and proximate features. The nutraceutical profile revealed that these specialty grains contained higher concentrations of antioxidant compounds (up to 3-fold when compared with the other grains). The rheological analysis demonstrated that sorghum grains developed higher peak viscosities than popcorn. According to the structural assessments, the type A pattern displayed peaks at the interplanar spaces corresponding to the crystalline and amorphous regions in all the samples. The data obtained in this study provides a base to further investigate the products obtained using these biomaterials

Fortificacion y evaluacion de tortillas de nixtamal

Se evaluó el efecto de la adición de vitaminas y pasta de soya desgrasada sobre la calidad de la tortilla de nixtamal (TN), así como las pérdidas de algunos nutrientes durante el proceso de nixtamalización. La adición de vitaminas y pasta de soya desgrasada se fijaron en 0.15% y 4% respectivamente, puesto que valores superiores afectaron negativamente el color y sabor en el producto. Se observó que el maíz pierde aproximadamente 1.5% de proteínas durante su transformación a tortilla, mientras que la tortilla de nixtamal fortificada con 4% de soya desgrasada (TNS) presentó 3% mas proteína que la TN. Los contenidos de calcio en las tortillas fueron de 7.7, 114 y 212.5 mg/100 g para el maíz, TN y para TNS respectivamente. Respecto a la pérdida de vitaminas durante la transformación de maíz a tortilla se cuantificó 29.0% de pérdida para niacina, 46.3% para ácido fólico, 36.4% para tiamina y 80% para riboflavina. Durante el lavado del nixtamal se pierden gran cantidad de vitaminas, se cuantificó una pérdida de 18.2% de tiamina, 16.6% de riboflavina y 20.7% de ácido fólico. Por el contrario la harina nixtamalizada integral, en cuyo proceso de elaboración no se contempla el lavado, presentó un balance de niacina positivo del 7.9%. Las pérdidas durante el cocimiento de la tortilla fueron muy elevadas especialmente para la riboflavina, ya que del 80% de pérdidas de esta vitamina durante el proceso total, el 63.8 % se presentó durante su cocimiento y el 16.6% durante el lavado del nixtamal.Fortification and evaluation of the nixtamal tortillas. The effect of the addition of vitamins and soy protein on the quality characteristics of nixtamal tortillas (TN) and the losses of nutrients during the nixtamalization process were evaluated. Vitamins (0.15% as is) and defatted soy (4% as is) were added to the tortillas without affecting their sensory characteristics. Higher values of those nutrients had a negative effect on the color and flavor of the product. During the production of the tortilla the corn lost approximately 1.5% of proteins. The nixtamal tortilla fortified with 4% of defatted soy (TNS) showed 3% higher protein content than the TN. The calcium content in the samples was 7.7,114 and 212.5 mg/100 g for the corn, the TN and the TNS respectively. In the process of produccing the nixtamal tortillas from corn 28.9% of the niacin, 46.3% of the folic acid, 36.3% of the thiamin and 80% of the riboflavin were lost. During the washing and rinsing of the nixtamal there were losses of 18.2% of the thiamin, 16.6% of the riboflavin and 20.7% of the folic acid. Although the niacin showed a 28.9% loss, the alkaline process caused an important release of that vitamin. The losses during the cooking of the tortillas were high especially for riboflavin which showed a total loss of 80% in comparison with the original corn. Of the total, 63% was lost during cooking and 16.6% was lost during washing of the nixtamal

Optimization of acetylated starch films from purple sweet potato: effect of glycerol, carboxymethylcellulose, and stearic acid

The objective of this study was to ascertain the optimal additive conditions to develop a film from an alternative source of modified starch, using the response surface methodology. The central composite design + points used factors to evaluate the effect of the independent variables (glycerol concentration: 0.3, 0.35, and 0.40 g g ^−1 starch; carboxymethylcellulose: 0.5, 0.75 and 1 g/5 g starch; stearic acid 0.025, 0.05, and 0.075 g/5 g starch) on the response variables (solubility, swelling, opacity, luminosity, tensile strength, elongation, water vapor permeability, and water activity). A simultaneous optimization was achieved using concentrations of glycerol 0.30 g g ^−1 starch, CMC 0.32 g/5 g starch, and stearic acid 0.007 g/5 g starch, which generated interesting properties validated through experimentation. Therefore, an ecological film was obtained that can be considered for food coating because it presented a low permeability to water vapor (0.0055 g ms ^−1 MPa ^−1 ), a high percentage of elongation (91%), and a decrease in solubility (23%). This will also allow the incorporation of other compounds such as antioxidants, reinforcements, and sensors with favorable results, and with a positive perspective on the use of alternative sources of starch

Antioxidant Properties of Polyphenolic Extracts from Quercus Laurina, Quercus Crassifolia, and Quercus Scytophylla Bark

The objective of this work was to determine the concentration of total phenols, total flavonoids, hydroxycinnamic acids, and proanthocyanidins present in crude extracts of Quercus laurina, Q. crassifolia, and Q. scytophylla bark. They were extracted by ethanol (90%) maceration and hot water. The antioxidant capacity was determined by the ability to capture OH•, O2•−, ROO•, H2O2, NO•, and HClO. The hot water crude extract of Q. crassifolia was chosen to be concentrated and purified due to its higher extraction yield (20.04%), concentration of phenol compounds (747 mg gallic acid equivalent (GAE)/g, 25.4 mg quercetin equivalent (QE)/g, 235 mg ChAE/g, 25.7 mg chlorogenic acid equivalents (ChAE)/g), and antioxidant capacity (expressed as half maximal effective concentration (EC50, µg/mL): OH• = 918, O2•− = 80.5, ROO• = 577, H2O2 = 597, NO• ≥ 4000, HClO = 740). In a second stage, Q. crassifolia extracted with hot water was treated with ethyl acetate, concentrating the phenol compounds (860 mg GAE/g, 43.6 mg QE/g, 362 ChAE/g, 9.4 cyanidin chloride equivalents (CChE)/g) and improving the scavenging capacity (OH• = 467, O2•− = 58.1, ROO• = 716, H2O2 = 22.0, NO• ≥ 4000, HClO = 108). Q. crassifolia had the highest polyphenolic concentration and the better capacity for scavenging reactive species, being a favorable candidate to be considered in the development of new products