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Sorghum is a cereal with little use in human diet; however, this grain can provide several nutrients and, additionally, has a high content of phenolic compounds concentrated in bran, which could be beneficial to human health due to its high antioxidant capacity. However, these bioactive compounds are bound within the cell wall matrix; it is necessary to release these compounds to take advantage of their antioxidant properties. The extrusion process increases the accessibility of bound phenolic compounds, breaking their bonds from the bran matrix. The aim of this study was to determine the optimal extrusion conditions for maximizing the phenolic compound content and antioxidant capacity of sorghum bran extrudate. The extrusion process factors evaluated were feed moisture (FM) from 25 to 35% and the fourth extrusion zone temperature (T) in the range of 140–180 °C. Analysis of variance and response surface analysis were used in the evaluation. The prediction coefficient, (FM)2, (T)2 and their interaction (FM)(T) significantly affected the free total phenolic compounds. The antioxidant capacity of the free total phenolic compounds was significantly affected by (FM)2 and (T)2. The optimal extrusion conditions were FM = 30% and T = 160 °C, which provided free total phenolic compounds with a value of 7428.95 μg GAE/g (predicted value: 7810.90 μg GAE/g) and antioxidant capacity with a value of 14.12 μmol TE/g (predicted value: 14.85 μmol TE/g). Results confirmed that extrusion process optimization was useful to increase the content of phenolic compounds and improved the antioxidant capacity of sorghum bran.

El objetivo de este trabajo fue evaluar el efecto de la sustitución de harina de trigo (HT) con harina de fibra de avena (HFA) con diferente tamaño de partícula sobre las propiedades reológicas, texturales y de panificación. El tamaño de partícula obtenido después de la molienda de la fibra de avena fue de 250 y 177 µm (micrones). Los porcentajes de sustitución utilizados fueron de 10, 20 ó 30%. A las mezclas de harinas se les determinó color, capacidad de retención de agua (CRA) y perfil de viscosidad. A las masas se les midió fuerza y extensibilidad por la prueba de Kieffer, mientras que al pan se le midió volumen específico, actividad de agua y perfil de textura. Los resultados mostraron incrementos de fuerza en la masa cuando se utilizaron las dos fracciones de HFA (250 o 177 µm) en la sustitución de HT con respeto a la obtenida de HT (0.25 N). En extensibilidad, los incrementos más importantes fueron observados cuando se utilizó HFA de 177 µm. El volumen específico del pan se vio favorecido cuando se utilizó 10 o 20% de HFA (177 µm) observándose valores muy parecidos entre ellos (4.54 y 4.56 cm3 g-1, respectivamente), sin mostrar diferencias significativas al obtenido de HT (4.57 cm3 g-1). El perfil de textura mostró la obtención de panes más blandos cuando se utilizó HFA (177 µm), en sus tres diferentes porcentajes de sustitución (4.86, 4.71 y 7.05 N), incluso mejoró al medido en HT (7.84 N).

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC, 22.2–35.7%), extrusion temperatures (ET, 102–142 °C), and screw speeds (SP, 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties, increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.

The blue corn-based products are considered functional foods due to their high concentration of anthocyanins. The aim of this study was to estimate the kinetic and thermodynamic parameters of the thermal degradation of anthocyanins from extruded nixtamalized corn products. A comparative study of anthocyanins thermal stability in these matrices in a buffer solution (pH 2.5) was investigated at different temperatures (60, 75 or 90 °C). Results showed the mechanism of anthocyanins degradation followed first-order reaction kinetics. The values of the reaction rate constant (k) were found to be in a range of 0.027–0.037 h−1 at 60 °C, 0.107–0.113 h−1 at 75 °C and 0.340–0.354 h−1 at 90 °C. The higher the k value was, the shorter the half-life time and D-value. The activation energy (Ea) and z-values were in the range of 75.1–89.2 kJ/mol and 28.8–35.1 °C, respectively. The coefficient Q10 indicated the reaction rate approximately doubles with every 10 °C temperature increase. ∆H, ∆S and ∆G indicated the degradation of anthocyanins was an endothermic and nonspontaneous reaction. Even the major susceptibility of the anthocyanins in extruded nixtamalized corn products at the time–temperature combination applied, there was not difference between flour and tortilla, this imply that most of the anthocyanins were degraded during the nixtamalization extrusion process and no significative further degradation occur in the cooking step. This study provides and advance in the knowledge on the effect of nixtamalization extrusion process and tortillas making on the stability of anthocyanins from blue corn. However, further studies are needed.

Se evaluó la actividad antioxidante y caracterizó parcialmente la calidad proteica in vivo de harinas de amaranto obtenidas por extrusión a tres niveles de humedad de alimentación (HA) y dos niveles de temperatura (T). Se realizó análisis químico proximal, fenoles totales (FT), y actividad antioxidante (AA). Los tratamientos con mayores y menores niveles de HA y T fueron evaluados en su calidad proteica usando un modelo murino, se incluyeron como referencia harinas de amaranto inflado comercial y sin procesar. Se evaluó la razón neta de proteína (RNP), digestibilidad aparente (DAN) y verdadera de nitrógeno (DVN). Los FT y AA disminuyeron hasta en un 30 y 56 %, respectivamente debido al proceso de extrusión. El análisis de calidad proteica in vivo mostró que los extrudidos de amaranto presentaron mayor DVN (85 y 86.72 % para los menores y mayores niveles de HA y T, respectivamente) con respecto al amaranto inflado (84.55 %) y el amaranto sin procesar (83.01 %). Las pruebas de RNP fueron significativamente diferentes entre harinas extrudidas (4.11-4.32), inflado comercial (3.76) y sin procesar (3.81). En conclusión, el procesamiento por extrusión mejora la RNP y digestibilidad de proteína, sin embargo, los fenoles totales y actividad antioxidante se ven disminuidos.ABSTRACTThe antioxidant activity was evaluated and partially characterized of the in vivo protein quality of amaranth flours obtained by extrusion at three levels of feed moisture (HA) and two temperature levels (T). We performed proximal chemical analysis, total phenols (FT), and antioxidant activity (AA). Treatments with higher and lower levels of HA and T were evaluated in their protein quality using a murine model, commercial and unprocessed amaranth inflated flours were included as reference. The net protein ratio (RNP), apparent digestibility (DAN)and true nitrogen (DVN) were evaluated. The FT and AA decreased by 30 and 56%, respectively, due to the extrusion process. In vivo protein quality analysis showed that amaranth extrudates have higher DVN (85 and 86.72 % for the lower and higher levels of HA and T, respectively) with respect to inflated amaranth (84.55 %) and unprocessed amaranth (83.01 %). The RNP tests were significantly different between extruded flours (4.11-4.32), commercially inflated (3.76) and unprocessed (3.81). In conclusion, processing by extrusion improves RNP and protein digestibility, however, total phenols and antioxidant activity are diminished.

In the baking industry, different processes and methods of freezing have been used for breadmaking to preserve a quality comparable to that of fresh bread. In this study, the effect of part-baking time, freezing rate, and frozen storage time on part-baked French bread quality was determined. The bread was part-baked for 0, 3 and 6 min, frozen at slow (0.15 °C/min) and fast (1.75 °C/min) freezing rates, stored under freezing conditions for up to 56 days and thawed every 14 days. Part-baked bread was rebaked, and the SV and firmness at 2, 24 and 48 h were obtained. An experiment with a factorial design of 3×2×5 (3 part-baking time, 2 freezing rates and 5 frozen storage times) with analysis of variance (ANOVA) at a confidence level of 95% was carried out. The highest SV was ​​obtained at 6 min of part-baking at a slow freezing rate and decreased as the frozen storage time increased. In contrast, TPA showed that bread firmness increases when the specific volume decreases, and the highest firmness is at 0 min of part-baked time. Relatively long part-baking times allow for firm crumb formation with limited damage to the structure and therefore bread with optimal quality.

El salvado de sorgo posee una alta capacidad antioxidante debido a su elevado contenido de compuestos fenólicos. Durante el decorticado del grano para la obtención del salvado, pueden presentarse reacciones de oxidación lipídica que deterioran su calidad. Para evitar esto, se emplean procesos de estabilización como la extrusión. El objetivo de este trabajo fue evaluar los cambios químicos en los compuestos fenólicos y la capacidad antioxidante del salvado de sorgo rojo extrudido. Los salvados de sorgo crudo (SC) y extrudido (SE) se almacenaron durante 42 días para poder evaluar los cambios químicos (índice de peróxidos, pH y ácidos grasos libres), en los compuestos fenólicos, su capacidad antioxidante y la presencia de ácidos fenólicos. El tipo de salvado fue el factor que más afectó los resultados de las evaluaciones químicas. La calidad del SE fue más estable en comparación con la del SC, el cual tuvo cambios significativos de ácidos grasos libres e índice de peróxidos. El contenido de compuestos fenólicos y la capacidad antioxidante de ambos tipos de salvado no se modificaron significativamente (p > 0.05) por efecto del tiempo de almacenamiento, sin embargo, el SE presentó niveles superiores en compuestos fenólicos y capacidad antioxidante que el SC. El proceso de extrusión del salvado de sorgo retarda la oxidación enzimática y mejora la extracción de los compuestos fenólicos.

The aim of this study was to evaluate the effect of extrusion factors on the properties of extruded nixtamalized corn flours (ENCFs), determine the optimal conditions, and produce a tortilla with texture and nutraceutical characteristics acceptable for consumers. The processing factors used were feed moisture (FM, 15 to 30%), extruder temperature (T, 70 to 110 °C), and screw speed (SS, 50 to 145 rpm). The properties evaluated in the flours were total anthocyanins (TA), subjective water absorption capacity, and peak viscosity (PV). Response surface methodology and analysis of variance were used in the evaluation. The linear and quadratic terms of FM had a greater effect on all evaluated parameters. The optimization was performed using the numerical method of global desirability. The response variables that were optimized in the ENCF were TAs (maximize) and PV (maximize). The optimal region was the following: FM (18.17%), T (92.03 °C), and SS (76.61 rpm). The experimental value for the TA in the optimized ENCF was 226.07 mg/kg, and the PV was 1063.9 cP. The results of this study could help develop nixtamalized corn flours with desirable characteristics to make tortillas using the extrusion process. PRACTICAL APPLICATION: The results obtained would be useful for the tortilla industry, developing nixtamalized corn flours with desirable characteristics to make healthy tortillas using the extrusion process, with minimum losses in biologically active compounds such as anthocyanins (health promoters) without affect negatively the eating quality of the product (good texture).

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 inG′andG″, 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 parametersG′andG″in temperature sweep mode to monitor changes in the degree of starch damage.

The extrusion process (EP) consists of heat and mechanical treatments under different conditions of moisture, shear, and pressure and rapidly causes structural alterations and changes in the functional properties of the extruded material. The aim of this study was to evaluate the effect of extrusion conditions and optimize the wheat bran extrusion conditions to achieve the greatest content of phenolic compounds and antioxidant activity using response surface methodology. The EP factors evaluated were feed moisture (FM) (25–33.54%) and final extrusion temperature (T) (140–180 °C). The properties evaluated in the extruded material were bound total phenol content (BTPC), total phenolic compounds and antioxidant activity (AOX). Analysis of variance (ANOVA) and response surface methodology were used in the evaluation. The determination coefficients, (FM)2 and (T)2, very significantly affected the BTPC and bound 2,2-diphenyl-1-picrylhydrazyl content (BDPPHC). The optimization was performed by overlaying two contour plots to predict the best combination regions. The optimized extrusion conditions were the following: FM = 30% and T = 140 °C, which provided BTPC = 3547.01 μgGAE/g (predicted: 3589.3 μgGAE/g) and BDPPHC = 9.5 μmolTE/g (predicted: 10.4 μmolTE/g); and FM = 30% and T = 180 °C, which provided BTPC = 3342.3 μgGAE/g (predicted: 3727.7 μgGAE/g) and BDPPHC = 9.5 μmolTE/g (predicted: 9.3 μmolTE/g). The EP increased the phenolic compounds and AOX, and enhancement of these properties in wheat bran products could make them functional foods.

Two ways of adding sorghum bran to tortillas were evaluated; adding to the corn flour before extrusion or after extrusion. The addition of sorghum bran increased the ferulic (FA), p-coumaric (p-CA), diferulic (di-FA) and triferulic (tri-FA) acids contents in corn flours and tortillas. Extrusion produced an increment of the free forms, and a part of the ferulic acid was degraded as a consequence of the extrusion conditions. Baking produced a reduction of bound and free forms of the phenolic acids in tortillas, however, high retention percentage of the phenolic acids was observed in flours and tortillas (83–90%). The antioxidant activity of flour and tortillas were correlated to the contents of the phenolic acids, especially with bound di-FA and tri-FA combined (r = 0.92). Adding the sorghum bran before extrusion, produced flours with increased free phenolic acids content, and increased in vitro antioxidant activity.

The effect of dough formation using dynamic rheology, thixotropy, zeta-potential, and FT-IR properties of soft wheat dough as a function of Ca(OH)2, and Ca-salts contents (0.3%, 0.7%, and 1.1%) was investigated. Physical data were further supplemented by measurements of dough texture profile analysis, wet gluten, and pH. Additional information provided by structure-sensitive properties, such as the zeta-potential, thixotropic index, and slopes of rheo-destroyed and complex viscosity curves using Cox–Merz rule, can comprise complementary instances of evidence of the ability of dough self-regeneration or build-up after rheodestruction to certain limits. There is a different behavior of the dough properties above and below pH 7.0. Above pI ≈ 5.2, dough (pH 5.5–7.0) has zeta-potential with negative charge from ionizing hydroxyl groups of starch and proteins that favor protein unfolding and that increase α-helix, wet gluten, and functionality. Weak non-covalent bonds and electrostatic forces induce strong entanglement and interaction with water, increase swelling, and preserve the chemical structure. However, at pH > 7.0, Ca(OH)2 treatment changed to negative charge tendency of the dough system, specifically of starch. The effects provided by nixtamalization are essential for its application in improvement of wheat flour with limited functionality, such as soft wheat flour and other grains or materials.

Chitosan fibers were prepared by wet spinning in three stages. Initially, a polymer solution of chitosan and polyvinyl alcohol (PVA) was solidified in a mixture of potassium hydroxide and ethanol. The polymers were then crosslinked with sodium tripolyphosphate (TPP) or glutaraldehyde, and finally dried in methanol or acetone. The effect of these conditions was evaluated based on scanning electron microscopy images, water-holding capacity, and swelling and mechanical properties. The miscibility of the mixture was evaluated using Fourier Transform Infrared spectroscopy and differential scanning calorimetry. The results obtained showed that chitosan fibers containing 45% (v/v) PVA and crosslinked using TPP have properties similar to those of commercial sutures prepared using other biomaterials.

Sorghum bran (SB) is a good source of phenolic compounds with high antioxidant capacity that increases the antioxidant activity (AOX) of tortillas prepared with extruded nixtamalized corn flour. The objective of this research was to study the effects of bran addition (0, 5, or 10%) before (ENBESB) or after (ENAFSB) extrusion, in the features and composition of baked tortillas in terms of total phenolic compounds (TPC), AOX, color (L, a, b, hue, chroma, and E value), and tortilla firmness. It was possible to retain more than 81.8 and 89.9% of TPC and AOX, respectively, in ENBESB-10% flour. Tortillas prepared with ENAFSB-10% flour retained more than 92 and 76% of TPC and AOX, respectively, compared with ENBESB. However, tortillas elaborated with ENAFSB flour showed a higher firmness and lower flexibility than counterparts produced from ENBESB. The use of extrusion to produce nixtamalized corn flours and the strategy of adding the SB to the corn meal before extrusion were essential to retain TPC and AOX and,...

Conventional plastic materials accumulation has led to a constant search to develop friendly packaging, edible coatings from biopolymers are an example. Since different proteins have different behavior and plastizicer compatibility, in this work, the effect of different polyalcohols (glycerol, sorbitol, maltitol, mannitol, and xylitol) as plasticizers on squid protein films behavior was studied. The results show that except for mannitol, transparent, and flexible films can be obtained. None of them showed transmission to light on the ultraviolet (UV) spectrum. However, only glycerol and sorbitol were sufficiently flexible to evaluate their mechanical properties, in which glycerol had a more elastic behavior with an elongation at a break of 920% and tensile strength (TS) of 0.94 MPa, while sorbitol exhibited a more plastic behavior with an elongation at break of 511% and a TS of 4.41 MPa. Water-vapor transmission rate was higher in glycerol, with 194.41 g&middot, m&minus, 2d&minus, 1, while sorbitol had 44.27 g&middot, 1 but presented blooming. This could be due to low interaction between sorbitol and the protein matrix, correlating with the film-solubility results. Amide I band of the Fourier transform infrared (FT-IR) spectra demonstrated higher denaturation and loss of alpha helical structure in glycerol film, followed by maltitol/sorbitol, xylitol, mannitol, and the control film. This in accordance with thermogravimetric analysis (TGA) results. The results of this study prove that only glycerol and sorbitol are suitable to obtain a see-through flexible film.

The objective of this study was to evaluate the in vitro effectiveness of membranes developed with pure chitosan and chitosan in a mixture with glycerol-honey against gram-negative bacteria isolated from skin ulcers. The membranes were prepared by the solvent evaporation technique. The identification and antibiotic sensitivity of microorganisms were determined in microplates, and in vitro tests were developed by the agar diffusion technique. The most frequently isolated microorganism was Escherichia coli with 43.75 % prevalence. All membranes showed antimicrobial effects by direct contact against Proteus mirabilis, Escherichia coli, Enterobacter aerogenes, Pseudomonas aeruginosa, Klebsiella pneumoniae and Morganella morganii. Antibiograms showed that most of these microorganisms are multi-resistant to antibiotics. All of this suggests that chitosan-based membranes are a safe alternative for the treatment of infected cutaneous ulcers compared to traditional antibiotics. The outcomes of this study confirm that membranes made of a biodegradable polymer, such as chitosan have activity against multidrug-resistant gram-negative bacteria that grow in infected skin ulcers.

Changes in the solubility of corn proteins occurring during traditional nixtamalization and extrusion processes used to produce tortillas were studied using size exclusion chromatography, SDS-PAGE and the Dumas method to measure 50% propanol-insoluble protein. Size exclusion chromatography (HPL-SEC) studies furthered the understanding of protein solubility changes during both processes. Extrusion caused more protein aggregation in tortilla intermediate and final products than traditional nixtamalization. Mixing during extrusion and in the intermediate step of masa production in the traditional nixtamalization process was critical in reducing protein solubility. Baking tortillas also considerably reduced the protein solubility for the traditional nixtamalization process. Baking produced aggregation that could not be disrupted with a reducing agent.

The aim of this study, was to evaluate the effect of extrusion conditions and particle size index on the starch properties of expanded nixtamalized snacks elaborated with whole blue corn. Whole grains were ground to achieve two different particle size indexes (PSI), 83.9 and 94.1, and were extruded at three feed moistures (14, 16.5, and 20.5%). The data suggested that the severity of milling and the extrusion process resulted in higher starch degradation, specifically in the snacks obtained with a feed moisture of 20.5%, which showed the higher values of starch damage. Nixtamalization by extrusion produced minimum amounts of resistant starch, mainly as retrograded starch and amylose-lipid complex, as demonstrated by thermal and structural analyses. Snacks produced with feed moisture of 16.5–20.5% and a PSI of 94.1 showed the highest values of resistant starch. The rheological properties of snacks with PSI of 83.9 indicated lower starch degradation and presented lower amounts of resistant starch than snacks with higher PSI. The feed moisture affected all the parameters evaluated in the snacks more than the PSI.

Summary Jumbo squid (Dosidicus gigas) is characterised by its low commercial value, lean and white meat without bones or scales and high muscular yield. Therefore, it is an attractive species for the production of protein concentrates. However, the gelling ability of squid proteins is low due to the inherent characteristics of the proteins. Different hydrocolloids can be used to improve the gelling ability, where pH and concentration of the hydrocolloids are very important to stablish. Therefore, this study aimed to obtain a protein concentrate from Dosidicus gigas and evaluate the effect of pH and chitosan concentration on its gelation and conformational changes. Treatment at pH 7.0 with 2% chitosan improved the water-holding capacity, elasticity and agglomeration according to the Z potential; it also improved the thermal stability and gelling according to the dynamic oscillatory measurements and differential scanning calorimetry. This information demonstrates that chitosan incorporation plays an important role in gel formation and improves the gelling capacity of squid proteins without affecting the brightness and whiteness, important parameters for this product.

Different studies on obtaining protein concentrates or surimi from giant squid ( Dosidicus gigas) have reported that soft gels are obtained in comparison with other fish species. Therefore, the aim of this research was to investigate the effect of the setting (30 and 60 °C, for 0, 30, 60, and 90 min) on the gelling capacity as a possible alternative to improve the textural characteristics of the gels. Treatments at 60 °C (G4, G5, and G6) had a higher percentage of insoluble protein, while the electrophoretic profile showed the presence of high molecular weight (HMW) aggregates, as well as the decrease of myosin, paramyosin and actin bands as the incubation time was increased. Likewise, these systems presented a lower content of total sulfhydryl (TSH), which is attributed to the formation of disulfide bridges. The texture profile analysis (TPA) showed that the setting application affected the different parameters evaluated (strength, elasticity, and cohesiveness). Setting as pretreatment did not prove to be a good alternative for the gelling of proteins from giant squid mantle, since the control treatment (no setting) was that which exhibited better textural characteristics.

Effects of different β-glucan concentrations in maize flour on the properties of frozen maize tortillas were evaluated. Masa (dough), pre-cooked (PTs), frozen (FTs), thawed (TTs), and cooked tortillas (CTs) were made and analyzed. Moisture content of masa and tortillas significantly decreased as β-glucan concentration increased; however, the water absorption capacity (WAC), ice melting enthalpy, and frozen water in FTs increased. Texture and color of the masa, PTs, and CTs as well as sensory analysis showed differences only between tortillas with 0% and 4% β-glucans. β-glucans did not affect the texture of CTs. Soluble fiber increased by over threefold and fivefold in tortillas with 2% and 4% β-glucans, respectively, than in those without β-glucans. This result was consistent with the observed structural changes in tortillas, showing an increase in high-fiber aggregates with increasing β-glucan concentration. Tortillas with 2% β-glucans showed acceptable physicochemical, functional, and sensory properties, but over three times the soluble fiber. Therefore, it is possible to obtain frozen tortillas with high fiber content and increase their shelf life for subsequent cooking while maintaining good properties.

Micro- and nanotechnology are tools being used strongly in the area of food technology. The electrospray technique is booming because of its importance in developing micro- and nanoparticles containing an active ingredient as bioactive compounds, enhancing molecules of flavors, odors, and packaging coatings, and developing polymers that are obtained from food (proteins, carbohydrates), as chitosan, alginate, gelatin, agar, starch, or gluten. The electrospray technique compared to conventional techniques such as nanoprecipitation, emulsion-diffusion, double-emulsification, and layer by layer provides greater advantages to develop micro- and nanoparticles because it is simple, low cost, uses a low amount of solvents, and products are obtained in one step. This technique could also be applied in the agrifood sector for the preparation of controlled and/or prolonged release systems of fertilizer or agrochemicals, for which more research must be conducted.

Lignin conveys several important and useful characteristics to starch films depending on the lignin MW, extraction procedure, and lignin botanical source. In this study, lignin was obtained from durum wheat straw through the organosolv process, followed by fractionation according to solubility in alcohol. The alcohol-soluble lignin (ASL) was then used to prepare starch–ASL films. The mechanical properties, thermal stability, water solubility, color, and antioxidant activity of the resulting films were evaluated, and the starch–ASL films were also analyzed by means of SEMand attenuated total reflection infrared spectroscopy (ATR-IR). A procedure, to incorporate ASL, was developed and used to produce homogenous surfaces in starch–ASL films; agglomerations or undissolved particles of lignin were not observed in the starch matrix at microscopic level. ASL promoted significant decrease of the tensile strength (TS) and elastic modulus (EM), but an increase of elongation at break (EB) in films. Thermal analysis of the starch–ASL films showed high resistance to thermal degradation, due to the incorporation of ASL. In addition, the starch– ASL films exhibited antioxidant activity (2,2-diphenyl-1-picrylhydrazyl [DPPH]), which increased with increasing ASL content.

Bread is one of the most consumed foods in the world, and alternatives have been sought to extend its shell life, and freezing is one of the most popular methods. The purpose of this study was to evaluate the effect of freezing rate and trehalose concentration on the fermentative and viscoelastic properties of dough and bread quality. Dough was prepared and trehalose was added at three concentrations (0, 400, 800 ppm); dough was pre fermented and frozen at two freezing rates then stored for 42 days. Frozen dough samples were thawed every two weeks. CO2 production and elastic and viscous modulus were determined. In addition, bread was elaborated and specific volume and firmness were evaluated. High trehalose concentrations (400 and 800 ppm) produced dough with the best viscoelastic and fermentative properties. Greater bread volume and less firmness were observed when a slow freezing rate (-.14 °C/min) was employed.

Extrusion is an alternative technology for the production of nixtamalized products. The aim of this study was to obtain an expanded nixtamalized snack with whole blue corn and using the extrusion process, to preserve the highest possible total anthocyanin content, intense blue/purple coloration (color b) and the highest expansion index. A central composite experimental design was used. The extrusion process factors were: feed moisture (FM, 15%-23%), calcium hydroxide concentration (CHC, 0%-0.25%) and final extruder temperature (T, 110-150 °C). The chemical and physical properties evaluated in the extrudates were moisture content (MC, %), total anthocyanins (TA, mg·kg(-1)), pH, color (L, a, b) and expansion index (EI). ANOVA and surface response methodology were applied to evaluate the effects of the extrusion factors. FM and T significantly affected the response variables. An optimization step was performed by overlaying three contour plots to predict the best combination region. The extrudates were obtained under the following optimum factors: FM (%) = 16.94, CHC (%) = 0.095 and T (°C) = 141.89. The predicted extrusion processing factors were highly accurate, yielding an expanded nixtamalized snack with 158.87 mg·kg(-1) TA (estimated: 160 mg·kg(-1)), an EI of 3.19 (estimated: 2.66), and color parameter b of -0.44 (estimated: 0.10).

Myofibrillar protein are the principally responsible of gelling properties in fishery resource, hence, during protein concentrate or isolated proteins preparation, sarcoplasmic protein are discarded; however, myofibrillar protein can support low levels of sarcoplasmic proteins without affecting the gelling property. Therefore, the aim of this study was to gradually remove sarcoplasmic proteins from giant squid mantle by means of different ionic strengths (I). Solutions of NaCl with different ionic strengths (I=0.0, 0.1, and 0.3) were used to obtain 3 protein concentrates. The electrophoretic profile in SDS-PAGE showed differences in protein removal with a high solubility of mantle proteins. The texture profile analysis showed that hardness increased in mantle protein washed with higher I. The total reactive sulfhydryls showed significant changes (p

The extrusion process allows the production of nixtamalized corn flour rich in arabinoxylans, which help to prevent cardiovascular and intestinal diseases. During extrusion, physiochemical properties of nixtamalized corn flour are negatively modified. The use of enzymes such as xylanase in order to obtain nixtamalized corn flour using extrusion has been studied as an alternative to reduce these changes in corn flour tortilla. The aim of this research was to evaluate changes in protein solubility of extruded nixtamalized corn flour with and without different concentrations of xylanase enzyme (0.05, 0.075, and 0.1 %, w/w). Soluble proteins of each corn flour were extracted and analyzed by SE-HPLC, while insoluble proteins were determined by the combustion method. In addition, each corn flour was analyzed by scanning electron microscopy (SEM). Results showed that the extruded nixtamalized corn flour, with and without xylanase, increased the protein solubility, and this effect was lower in extruded nixtamalized corn flour with xylanase. Insoluble protein diminished in corn flours either with or without xylanase enzyme. The addition of xylanase reduces the effect that the extrusion process has on the solubility proteins of extruded nixtamalized corn flour.

The stability of antioxidants in extruded and nixtamalized blue maize flours with calcium hydroxide [Ca(OH)2] and calcium lactate [C6H10O6Ca] were evaluated. Extruded blue maize flours batches were obtained by mixing blue maize flours separately with different Ca(OH)2 (0.1, 0.2 and 0.3 %) and C6H10O6Ca (0.3, 0.6 and 0.9 %) concentrations respectively and extruded to obtain the extruded flours. For nixtamalized flours, the maize grains were cooked at 1 % Ca(OH)2 and 2.95 % C6H10O6Ca concentrations respectively. Color, antioxidant activity, total phenolics, total anthocyanins and individual anthocyanins, contents were analyzed. Color, antioxidant activity, anthocyanins contents and total phenolics decreased as the calcium hydroxide concentration increased. In contrast, increasing the calcium lactate concentration on the extruded flours had the opposite effect. The extrusion process retained 57–47 %, 72–62 % and 79–65 % of the anthocyanins content, total phenolic content and antioxidant activity, respectively. These retention rates were higher than those of the nixtamalized flours using the same calcium sources. Cyanidin-3-glucoside and pelargonidin-3-glucoside were identified in the maize kernel and flours. Cyanidin-3-glucoside concentration was increased by both extrusion and nixtamalization processed with either of the two calcium sources. In contrast, pelargonidin-3-glucoside concentration decreased by both processes. Other anthocyanins were observed, but they were not identified.

The aim of this study was to evaluate the effect of the freezing rate and storage time on the solubility of gluten proteins and on the fermentative and rheological properties of dough as well as the bread quality. Increased storage time very significantly decreased (P

Nixtamalized blue corn expanded extrudates were elaborated in a single screw extruder using feed moisture (FM) of 14, 15, 16, 16.5, 18.5 and 20.5%; ground corn with different particle size indexes (PSI, 83.97 and 94.15), and at a final extruder temperature of 130 and 140°C. The physicochemical properties of extrudates evaluated were moisture content, total anthocyanin and cyanidin 3-glucoside (C3G) content, color, density and expansion index. Extrudates processed at 16 and 16.5% of FM showed higher total anthocyanin and C3G contents. The extrudates processed with 16% FM, at 130°C and PSI of 83.97, showed the highest total anthocyanin content (211.1 mg · kg−1). Cyanidin 3-glucoside showed an increase (11.3%) in extrudates when compared with raw corn. The expansion index was higher for those made with FMs of 14, 15, 16 and 16.5%. The total anthocyanin and C3G contents were not correlated with any other parameter.

Arabinoxylans (AXs) are cell wall non-starch polysaccharides of cereal grains and are depolymerized by xylanase affecting the rheological properties of their doughs. In this study, corn was ground and mixed with lime; xylanase (0.075 g/g corn) was diluted with water and added to the mixture to achieve a moisture content of 300 g/kg, and the mixture was extruded to obtain flour for producing tortillas. The water absorption capacity (WAC), water absorption index (WAI), AX content and molecular weight (AXMW) distribution, and ferulic acid (FA) content of the flour were then determined. The texture of the tortillas was assessed, and a sensory evaluation was performed. The flour with xylanase showed higher AX contents (24.1 g/kg dry matter) and smaller AXMW distribution (0.53–506 kDa) than the flour without xylanase. The extruded flour presented an FA content of 0.063–0.068 µg/mg AXs. The addition of xylanase decreased the tortilla firmness by 16–18.6% and had acceptable organoleptic characteristics.

The increasing demand for high-fiber products has favored the design of numerous bakery products rich in fiber such as bread, cookies, and cakes. The objective of this study was to evaluate the dietary fiber and estimated glycemic index of cookies containing extruded wheat bran. Wheat bran was subjected to extrusion process under three temperature profiles: TP1;(60, 75, 85 and 100 °C), TP2;(60, 80, 100 and 120 °C), and TP3;(60, 80, 110 and 140 °C) and three moisture contents: (15, 23, and 31 %). Cookies were elaborated using extruded wheat bran (30 %), separated into two fractions (coarse and fine). The dietary fiber content of cookies elaborated with extruded wheat bran was higher than the controls; C0 (100 % wheat flour) and C1 (30 % of no extruded bran coarse fraction) and C2 (30 % of no extruded bran fine fraction). The higher values of dietary fiber were observed on cookies from treatments 5 (TP1, 31 % moisture content and coarse fraction) and 11 (TP2, 31 % moisture content and coarse fraction). The estimated glycemic index of cookies ranged from 68.54 to 80.16. The dietary fiber content of cookies was increased and the lowest glycemic index corresponded to the cookies elaborated with extruded wheat bran. Cookie made with the treatment 11 had a better dietary fiber content and lower estimated glycemic index.

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.

Summary The antibacterial effect of polyamide 6/66-chitosan blend and chitosan-coated plastic films was compared to chitosan films and chitosan solution, against Salmonella typhimurium and Staphylococcus aureus. The chitosan films did not show inhibition halos; however, contact inhibition was observed. During the tests, the films absorbed moisture, increasing of the diameter discs in relation to the concentration of the chitosan for both microorganisms at least 31%. Chitosan plastic film coating (bilayer system) showed only contact inhibition, without increase in contact area. The films from polyamide 6/66-chitosan blend had no antibacterial activity. The highest inhibitory effect resulted from a chitosan solution at 1000 and 2000 ppm for S. typhimurium and S. aureus, respectively. The results of this study showed that the antimicrobial activity was lessened when the chitosan was combined with the plastic matrix because of the absence of contact inhibition, and the best activity was obtained with films prepared by casting of chitosan solution.

The stress relaxation behaviors of soft and bread-type wheat kernels were studied using the generalized Maxwell model. The data showed two phases, a fast phase at short times of about 1.52–16.88 sec (τ1 and τ2) and a slow phase with longer times of about 81.28–793.81 sec (τ3 and τ4). The shorter decay of σ1 can be explained by very weak forces that affect mainly the rheological properties. The slow decay (σ4) located at longer relaxation times resulted from strong forces. The first derivative obtained from the stress relaxation curve of intact wheat kernels was quite similar in shape to the dough farinograms. The stress relaxation parameters showed differences in springs, relaxation times, and viscosities of bread wheat compared with soft-type wheat kernels. The stresses σ1 and σ4 were correlated with wheat kernel, flour, rheological, and breadmaking properties; so especially were the elasticity of the spring (σ0) and viscosity of the fourth Maxwell element (η4), which were significantly correlat...

Whole white corn was ground, and lime, water and xylanase enzyme (0.05, 0.075 or 0.1% w/w) were added. Blends were extruded, dried and ground to obtain extruded nixtamalized corn flour (ENCF), which was used to make tortillas. The water absorption index and water absorption capacity (WAC) of the corn flours were determined. Viscoelastic characteristics were determined in corn masa made of extruded nixtamalized flours. Tortillas were made, and determination of moisture content and texture (cutting force and rollability) during storage was carried out. Furthermore, tortillas were evaluated by sensory evaluation. The flours containing xylanase showed significantly higher WAC (P

Cellulose nanofibers from durum wheat straw ( Triticum durum ) were produced and characterized to study their potential as reinforcement fibers in biocomposites. Cellulose was isolated from wheat straw by chemical treatment. Nanofibers were produced via an electrospinning method using trifluoroacetic acid (TFA) as the solvent. The nanofibers were 270 ± 97 nm in diameter. Analysis of the FT-IR spectra demonstrated that the chemical treatment of the wheat straw removed hemicellulose and lignin. XRD revealed that the crystallinity of the cellulose was reduced after electrospinning, but nanofibers remained highly crystalline. The glass transition temperature (T(g) value) of the fibers was 130 °C, higher than that of cellulose (122 °C), and the degradation temperature of the fibers was 236 °C. Residual TFA was not present in the nanofibers as assessed by the FT-IR technique.

A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G’) modulus of 40 Pa and gel set time (G’ > G’’) of 3 min at 1% (w/v), and a G’ of 131 Pa and gel set time of 1 min at 2% (w/v). The G’ of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material.

The physiological disorder of yellow berry (YB) in wheat is characterized by starchy or mealy spots in the grains, and it is present mainly in irrigated wheat crops. YB grains have characteristic low protein content. This disorder is a problem that has been increasing in bread and durum wheat in the northern part of Mexico. Limited availability of nitrogen is considered to be the main cause. Starch of normal and yellow berry wheat grains were analyzed and properties were compared. Starch of YB wheat grains had higher percent crystallinity, as demonstrated by X-ray diffraction and DSC studies. Differences in pasting behavior were also observed. Starch from YB wheat grains had higher peak and set back viscosities. Starch granule size distribution as well as physicochemical properties indicates changes in composition or microstructure of starch granules of YB wheat grains.

Acid hydrolysis process (AHPS) combined with hydrothermal storage process (HSPS) and extrusion cooking process (ECPS) are performed to obtain resistant starch (RS) from corn starch (CS). CS is subjected to AHPS citric, phosphoric acids, and HCl and thermal processes: 1) ECPS at 100 °C, 18% moisture content, and 220 rpm; 2) HSPS at 120 °C for 1 h, then storing at low temperature (4 °C) for 24 h. Evaluations in the different treatments are: RS, water absorption index (WAI) and solubility index (WSI); rheological, thermal, and microstructural properties. Treatment HAL results in the highest yield of RS (13.19 g/100 g), which increases WAI and WSI, low viscosity, gel hardness, ΔH and microstructural analysis showing agglomerated structures (30 µm) of diameter. On the other hand, HAC and HAP generated values of RS (8.47–9.19 g/100 g), respectively. Results show that pre-treatment by AHPS combined with HSPS is an alternative for obtaining RS, which exhibits suitable physical properties and is applicable to different dietary matrixes, at a 20-fold increased yield.

This study was carried out in order to compare the biochemical characteristics from three edible parts of the multipurpose tree Moringa oleifera such as the leaves, flowers, and immature pods. On average, the three most abundant amino acids were glutamic acid, arginine, and aspartic acid. The fatty acids present at the highest content were linolenic acid (C18:3ω3), palmitic acid (C16:0), linoleic acid (C18:2ω6), and oleic acid (C18:1ω9). The chemical composition (of dry weight) ranged from 19.34% to 22.42% for protein, 1.28% to 4.96% for lipids, 7.62% to 14.60% for ash, and 30.97% to 46.78% for dietary fiber. M. oleifera is a nonconventional plant with substantial nutritional value.

Microbial transglutaminase (MTGase), a protein-glutamine γ-glutamyl transferase (E.C. 2.3.2.13), catalyzes acyl transfer reactions by introducing a covalent cross-link between l-lysine and l-glutamine residues. The use of this enzyme has been proposed as an improver to increase dough strength. The objective of this study was to assess and compare the effect of MTGase on different fractions of dough proteins found in hard, soft, and durum wheat. Three different concentrations of the MTGase (0, 5, and 10U/g of gluten) were tested. Moisture, protein, and dry gluten contents were determined for each concentration in addition to rheological measurements done with the farinograph. Following each treatment, the dough proteins were extracted and analyzed by SE-HPLC and RP-HPLC. Soluble polymeric protein, gliadins, albumins, and globulins were quantified in addition to the gliadin subclasses and glutenin subunit types. The combustion procedure was used to determine the amount of insoluble polymeric protei...

The use of starch for the production of biodegradable materials has been increasing. Wheat is an important source, however, durum wheat starch and its separated granular components had not been evaluated for this purpose. The aim of this study was to evaluate the physical and mechanical properties of durum wheat starch films when prepared with a distribution of different granular-sized starches (A- and B-type). Starch was isolated, and the A and B populations of granules were separated. Films were prepared by casting. Glycerol (G) was used as a plasticizer in concentrations of 25% and 40%, respectively. Starch films were evaluated using scanning electron microscopy (SEM), mechanical properties (tensile strength, TS, elongation at break, E, elastic modulus, EM), solubility, and X-ray diffraction (XRD). Durum wheat starch films were transparent, flexible, and, according to SEM, highly homogeneous. Films prepared with 25% G showed brittle material behavior (TS = 42-50 MPa, E = 1.4-2.7%, and EM = 31-34 MPa), whereas those prepared with 40% G had ductile material characteristics (TS = 11-17 MPa, E = 4-41%, and EM = 4-11.3 MPa). These mechanical properties of the films were significantly affected by the glycerol concentration and the starch granule type used. The film solubility was low when compared to those reported in other studies. It increased with increasing plasticizer concentration. According to the XRD, the films showed a semi-crystalline structure.