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The nixtamalization process used for tortilla production entails extended processing time and generates pollutant effluents. Ohmic heating (OH) is an emerging technology that uses an alternating electric current for rapid and uniform food heating and mitigates effluent concerns. However, gaps exist in nutrient bioavailability studies. In this work, we assessed OH’s impact on tortilla nutritional value, protein, and calcium using a rat model. Twenty-five male Wistar rats were fed one of four diets for 21 days: raw corn (RC) as an experimental control, OH-processed tortillas (OHTs), traditionally processed tortillas (TPTs), commercial tortillas (CTs), and a casein diet (CD) as a growth control. Despite similar protein and macronutrient profiles, OH significantly enhanced insoluble fiber content. The weight gain sequence was OHTs > TPTs > CTs > RC. OHTs exhibited superior protein digestibility (88.52%), which was 3% higher than other diets. The serum albumin (2.63–2.73 g/dL) indicated moderate malnutrition due to the tortilla’s lower protein content. Nonetheless, the protein efficiency ratio (1.2–1.74) showed no significant difference from TPTs. Bone characteristics and fracture strength resembled the tortilla-fed groups, surpassing RC. X-ray diffraction and scanning electron microscopy confirmed that the OHT and TPT diets improved male rat bone thickness and crystallinity. The findings suggest the potential for OH as an eco-friendly tortilla production method, maintaining nutritional value comparable to traditional methods.

In this research, the mathematical model associated with the hydrothermal dehydration process of Nixtamalized Corn Grains (NCG) with different Steeping Time (ST) values, allows the fitting of experimental data with initial moisture M0 and the equilibrium moisture ME as a function of Isothermal Dehydration Time (IDT). The moisture percentage for any time t and dehydration rate (isolines M(t) and isolines vI respectively) of the NCG is shown by means of matrix graphics as a simultaneous function of IDT and ST. The relationship between initial dehydration rate v0 and initial moisture M0 establishes as a function of ST. Also, the mathematical model associated with the solution of the second Fick’s law allows calculating the diffusivity rate vk (H2O molecules out of NCG) and verify that the rate of change in moisture and the dynamical proportionality constant k has a non-linear dependence on the IDT and that k is directly proportional to Deff. The k values strongly relate to ST and the calcium ions percentage into NCG according to solubility lime values into cooking water (or nejayote) as a function of decreasing temperature when ST increases.

The objective of the study was to perform a nutritional analysis and antioxidant capacity of three varieties of sweet potatoes, Ipomoea batatas L., from Mexico, classified by color as: purple, yellow and white. In addition, sweet potato extrudates were produced and evaluated for their nutritional, antioxidant, sensory and texture properties. The average content of macronutrients for the three varieties was 77.92 g of carbohydrate, 10.51 g of dietary fiber, 8.25 g of protein, and 0.53 g of lipid per 100 g tuber on a dry matter (DM) basis. The purple variety exhibited the highest content of fiber as well as zinc and sodium, and the white one displayed the highest content of protein. In turn, contents of calcium, iron, and magnesium were the highest in yellow potatoes. Ascorbic acid content ranged from 60.6 to 106.0 mg/100 g DM, being higher in the yellow potatoes, and the total phenolic content ranged from 216 to 581 mg GAE/100 g DM, being higher in the purple potatoes. The average antioxidant capacity was 40.7 and 23.4 μmol TE/g DM in DPPH and ABTS assays. A lower total phenolic content and antioxidant capacity of extruded sweet potatoes were found with respect to the fresh ones. Among the extrudates, the purple ones had the highest total phenolic content (307 mg GAE/100 g DM) and exhibited the highest antiradical activity in the ABTS assay (15.5 µmol TE/g DM). They were also scored the highest in the sensory analysis, although the instrumental texture analysis showed their greater hardness (64.4 N) compared to the yellow and white extrudates (46.9 and 30.5 N, respectively). Extrudates of the three potato varieties exhibited a sweet taste and, thus, can be considered as sweetener substitutes in snacks with increased nutritional and bioactive potential.

Maize and sorghum have been recognized for their nutritional and agricultural properties and relevance. The primary objective of this research was to evaluate the phenolic content, antioxidant capacity (AC), and sensory attributes of gluten-free bread elaborated with nixtamalized sorghum and maize. Phenolic content was evaluated by Folin-Ciocalteu method and antioxidant capacity was assessed by ABTS (2,2’-azino-bis (3-ethylbenzthiazo-line-6-sulfonic acid)) and DPPH (1,1-diphenyl-2-picrylhydrazyl). The phenolic content of the bread samples ranged from 1.23–3.67 and from 2.41 to 6.22 mg GAE (gallic acid equivalents)/g sample for maize and sorghum breads, respectively. The AC was assessed using ABTS and DPPH radical, results of this parameter presented a strong correlation with phenolic content. Also, with the ABTS methodology lower values of AC were obtained. Breads elaborated with nixtamalized flours have antioxidant capacity. Among the breads evaluated, sorghum breads received higher overall acceptance as compared to maize breads and higher values of phenolic content and AC.

Non-alcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease worldwide. The objective of this study was to develop cookies added with flour from Opuntia atropes cladodes and Opuntia joconostle fruits and to evaluate the hypolipidemic-hepatoprotective effect in Wistar rats. Rodents were fed for 12 weeks with a hyperlipidic diet to induce obesity and NAFLD. Diets based on cookies were evaluated on the biochemical parameters in the blood and the liver (F1, with 15 % O. atropes cladodes flour; F2, with 15 % O. joconostle fruit flour; and F3, with 15 % of a 1:1 mixture of flours derived from O. atropes cladodes and O. joconostle fruits). Rodents that were fed with diets based on F1, F2, and F3 showed a decrease in the Lee index of 8.0 %, with the total lipid content and triacylglycerols in the liver being 36.5–41.4 % and 54.9–73.1 %, respectively. The F1 group showed a reduction in weight gain of 30.8 % in comparison to the positive control group. These effects were attributed to the flavonoid compounds and dietary fiber. This is the first study that reports the combination of O. atropes cladodes and O. joconostle fruits in cookies, which could prevent NAFLD and obesity.

The food-use of the tamarind ( Tamarindus indica L.) fruit produces shell and seeds as by-products. In this work, the effects of the tamarind shell moisture content and the temperature of their extrusion on the dietary fiber content and physiochemical properties, such as water absorption capacity (WAC), oil absorption capacity (OAC), and glucose dialysis retardation index (GDRI) of the extrudates, were estimated. Moreover, the effects of the extrusion variables on the total phenolic and total flavonoid contents and on the antioxidant capacity of the tamarind shell were evaluated. The dry powdered tamarind shell was conditioned to have 32 or 39 g of water per 100 g of shell, prior to being subjected to extrusion. Subsequently, the conditioned samples were processed at 90°C, 100°C and 110°C in a single screw extruder. A non-extruded tamarind shell was taken as a control. The extrusion resulted in a 138.3% increase in the soluble dietary fiber content, along with 40.3% and 18.4% reductions of total phenolic and total flavonoid contents, respectively. The antioxidant capacity of the tamarind shell with moisture content of 32 g/100 g extruded at 100°C and 110°C was similar to that of non-extruded material. Moreover, the extruded products had the higher OAC compared to that of the control and they displayed an excellent response with regard to controlling the GDRI. The extrusion advantageously modified properties of the tamarind shell particularly when material with a moisture content of 32 g/100 g at 100°C was processed.

Streptomyces species have been successfully used in diverse biotechnological processes; however, little is known about actinobacterial biofilm formation and its use as a biofilmed inoculant. The present study assessed and compared the ability of some plant growth-promoting actinobacterial strains to form biofilms on a carrier to improve microbial survival and colonize the rhizosphere and roots of Triticum aestivum, resulting in positive interactions and benefits to the plant. Forty-one actinobacterial isolates from Persea americana organic rhizosphere farms were tested on plant growth and biofilm-forming capacities, showing their potential use as bio-fertilizers in agriculture. Three Streptomyces strains were selected and tested for biofilm formation and plant growth-promoting (PGP) features. Biofilms were induced on the perlite carrier and used to inoculate seven treatments with T. aestivum in pot essays, resulting in a >200% increase in root weight and a >400% increase in total biomass. Endophytic colonization was achieved in all the treatments. Microbial survival ranged between 108 and 109 CFU/g after 12 weeks of treatment, indicating actinobacterial permanence on the carrier. Successful consortia formation was observed for mixed-strain treatments, suggesting long-term plant recolonization.

The derived materials obtained from the sol-gel process have been used in various technological applications, such as solar cells, intelligent coatings, catalysis, and, more recently, the fabrication of bioreceptors. The objective of this study was to develop a bioreceptor consisting of a titania-based nanostructure, which was synthesized using the sol-gel method. This nanostructure was immersed in a solution containing laccase and Nafion and integrated into a graphite-based electrode (TiO _2 /NAF/LAC). This device is called a bioreceptor and is used to detect gallic acid. The nanostructure was characterized by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). Particle size was measured using a nanosizer. Cyclic voltammetry (CV) tests were performed on a bioreceptor. In this study, the predominant phase of TiO _2 was anatase, and the obtained nanoparticles had an average size of 66 nm. The CV tests of the bioreceptor showed an oxidation response that increased as the concentration of gallic acid in the solution increased, with a detection limit of 0.125 μ M, as well as a wide linear range that varied from 0.125 to 175 μ M and a factor correlation of 0.9968. As a result, it was possible to develop a bioreceptor capable of immobilizing laccase to detect gallic 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.

Un alimento funcional contiene en su formulación una o más sustancias que generan bienestar a la salud humana como son probióticos, prebióticos y ácidos grasos, entre otros. En los alimentos funcionales los microorganismos probióticos deben permanecer viables y activos en el alimento y durante el pasaje gastrointestinal, para garantizar su potencial efecto benéfico en el huésped. En el presente estudio se evaluó la viabilidad de la levadura probiótica Saccharomyces boulardii tanto de forma libre como encapsulada bajo condiciones de acidez, adaptada a un queso fresco. Método: La levadura fue expuesta en el alimento tanto en forma libre como encapsulada. Los materiales usados para encapsular fueron una mezcla de alginato de sodio, inulina y mucílago de nopal (Opuntia ficus-indica). Para la liberación del microorganismo, el estudio se realizó a pH de 2.0 y 6.5, simulándose las condiciones de acidez de estómago y colon respectivamente, a diferentes tiempos de exposición de 0, 60, 120 y 180 min. Resultados: A pH de 2.0 se observó mayor pérdida en la viabilidad del probiótico en forma libre, la cual fue de 23.72, 27.03 y 33.02 % respectivamente, con respecto a la viabilidad inicial; cuando el microorganismo se adicionó al queso en forma encapsulada, su pérdida de viabilidad a los mismos tiempos de exposición fue de 5.74, 14.24 y 18.81%, manteniendo mayor supervivencia. Por otra parte, a pH de 6.5 el probiótico libre en el alimento mostró una pérdida de viabilidad de 2.23, 3.50 y 5.94%, en cambio de forma encapsulada la pérdida de viabilidad fue de 0.95, 2.20 y 3.03%, respectivamente, observándose mayor supervivencia que en estado libre. Conclusión: El queso fresco mantuvo viable el nivel de supervivencia de Saccharomyces boulardii, particularmente cuando fue adicionado en forma encapsulada comparado a cuando fue incorporado en estado libre.

Raw milk is one of the most important food for human consumption, particularly for small dairy farms who produce milk either self-consumption or to sell it to local artisanal cheese makers; due to the elevate risk of contamination by pathogenic bacteria, it is important to offer alternatives to enhance microbiological quality of raw milk. Thus, the objective of this study was to evaluate the addition of liquid mucilage and dried mucilage from Opuntia ficus-indica and Opuntia atropes to the raw milk on the growth of mesophilic aerobic bacteria and total coliforms. Raw milk samples from Holstein cows supplied by a smallholder was added with liquid mucilage or dried mucilage from O. ficus-indica or O. atropes at concentrations of 0.5, 1.0 and 2.0%. Samples were measured for mesophilic aerobic bacteria and total coliforms and results were analyzed by the fixed effects model and means comparisons. In general, counts of mesophilic aerobic bacteria and total coliforms were significant reduced (P

The biosorption of As(V) from aqueous solutions by pine sawdust chemically modified with iron in batch systems was investigated. The loading process of Fe in this biomaterial was achieved by hydrolysis of two different ferric salts. This modification of sawdust is an attempt to improve As(V) biosorption for practical applications. The kinetics and maximum biosorption capacities of the unmodified and modified pine sawdust were evaluated. It was found that the pseudo-second order model described the As(V) biosorption kinetic data and the Langmuir-Freundlich equation described the arsenate sorption equilibrium. These results indicated that the sorption mechanism was chemisorption on a heterogeneous material. The pH effects governing biosorption capacities were also evaluated, showing a decrease as pH value rises, indicating that this biosorption process is highly pH-dependent. The estimated maximum biosorption capacities of As(V), based on the Langmuir-Freundlich fit to the data were, at pH 4, 4.4 mg/g of untreated sawdust, (UN-SW), 12.85 mg/g of ferric chloride modified sawdust (FeCl-SW), and 6 mg/g of ferric nitrate modified sawdust (FeNit-SW); and at pH 7, 2.6 mg/g of UN-SW, 5.9 mg/g of FeCl-SW, and 4.6 mg/g of FeNit-SW. Sorption capacities of iron-modified pine sawdust were evidently higher than other similar biosorbents previously reported.

Guava leaf (Psidium guajava L.) extracts are used in both traditional medicine and the pharmaceutical industry. The antioxidant compounds in P. guajava leaves can have positive effects including anti-inflammatory, anti-hyperglycemic, hepatoprotective, analgesic, anti-cancer effects, as well as protecting against cardiovascular diseases. In the present study, phenolic compounds and in vitro antioxidant capacity were measured in extracts obtained with polar and non-polar solvents from leaves of two varieties of guava, Calvillo Siglo XXI and Hidrozac. The quantity of total phenolics and total flavonoids were expressed as equivalents of gallic acid and quercetin, respectively. Hydroxyl radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity using fluorescein (ORAC-FL) in vitro tests were used to assess the radical scavenging abilities of the extracts. The total phenolics were higher in the aqueous fraction of the variety Calvillo Siglo XXI, while in the Hidrozac variety total phenolics were higher in the acetone and chloroform fractions. Total flavonoids were higher in all fractions in the variety Calvillo Siglo XXI. Total phenolics showed a highly positive correlation for ORAC-FL, and a moderately positive correlation with hydroxyl radicals. Finally, total flavonoids showed a slightly positive correlation for ORAC-FL and hydroxyl radicals. Both varieties of guava leaf extract showed excellent antioxidant properties.