Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 330
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38653895

RESUMO

In this study, the feasibility of using hydrochars as anodic doping materials in microbial fuel cells (MFCs) was investigated. The feedstock used for hydrochar synthesis was metal-polluted plant biomass from an abandoned mining site. The hydrochar obtained was activated by pyrolysis at 500 °C in N2 atmosphere. Under steady state conditions, the current exerted by the MFCs, as well as the cyclic voltammetry and polarization curves, showed that the activated hydrochar-doped anodes exhibited the best performance in terms of power and current density generation, 0.055 mW/cm2 and 0.15 mA/cm2, respectively. These values were approximately 30% higher than those achieved with non-doped or doped with non-activated hydrochar anodes which can be explained by the highly graphitic carbonaceous structures obtained during the hydrochar activation that reduced the internal resistance of the system. These results suggest that the activated hydrochar materials could significantly enhance the electrochemical performance of bioelectrochemical systems. Moreover, this integration will not only enhance the energy generated by MFCs, but also valorize metal polluted plant biomass within the frame of the circular economy.

3.
Food Funct ; 15(8): 4051-4064, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38535983

RESUMO

This study evaluated the nutritional profile and fiber content of innovative formulations of wheat-based biscuits enriched with chia seeds, carob flour and coconut sugar. The in vitro antioxidant, cytotoxic, anti-inflammatory and antimicrobial activities were also investigated to understand the potential health advantages of the incorporation of these new ingredients. The novel biscuits demonstrated significant improvements in protein and mineral content, with increases of 50% and 100% in chia biscuits, and up to 20% and 40% in carob biscuits, respectively. Fiber also notably increased, particularly in samples containing 10% carob flour, which increased four times as compared to wheat-based samples. The new ingredients exhibited antibacterial and antifungal activity, particularly against Yersinia enterocolitica (minimum inhibitory concentration 1.25 mg mL-1 in coconut sugar) and Aspergillus fumigatus (minimum inhibitory concentration/minimum fungicidal concentrations 2.5/5 mg mL-1 in chia seeds). However, the final biscuits only displayed antifungal properties. Carob flour and chia seeds had a remarkably high capacity to inhibit the formation of TBARS and promoted greater antioxidant activity in biscuit formulations, with EC50 values decreasing from 23.25 mg mL-1 (control) to 4.54 mg mL-1 (15% defatted ground chia seeds) and 1.19 mg mL-1 (10% carob flour). Only chia seeds exhibited cellular antioxidant, anti-inflammatory and cytotoxic activity, attributes that were lost when seeds were added into the biscuits. These findings highlight the potential health benefits of these ingredients, particularly when incorporated in new wheat-based formulations.


Assuntos
Antioxidantes , Fibras na Dieta , Farinha , Galactanos , Mananas , Valor Nutritivo , Triticum , Triticum/química , Fibras na Dieta/análise , Fibras na Dieta/farmacologia , Antioxidantes/farmacologia , Antioxidantes/química , Farinha/análise , Sementes/química , Gomas Vegetais/química , Gomas Vegetais/farmacologia , Anti-Infecciosos/farmacologia , Salvia/química , beta-Glucanas/farmacologia , beta-Glucanas/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Pão/análise , Antibacterianos/farmacologia , Antibacterianos/química , Goma Arábica/química , Goma Arábica/farmacologia , Animais , Testes de Sensibilidade Microbiana , Humanos
4.
Artigo em Inglês | MEDLINE | ID: mdl-38456984

RESUMO

Given the high impact of traditional mining, the recovery of rare earth elements (REEs) from hazardous waste materials could become an option for the future in accordance with the principles of the circular economy. In this work, the technical feasibility of REEs recovery from metal mine tailings has been explored using electrokinetic-assisted phytoremediation with ryegrass (Lolium perenne L.). Phytoextraction combined with both AC current and DC current with reversal polarity was applied (1 V cm-1, 8 h day-1) to real mine tailings containing a total concentration of REEs (Sc, Y, La, Ce, Pr, and Nd) of around 146 mg kg-1. Changes in REEs geochemical fractionation and their concentrations in the soil pore water showed the mobilization of REEs caused by plants and electric current; REE availability was increased to a higher extent for combined electrokinetic-assisted phytoextraction treatments showing the relevant role of plants in the process. Our results demonstrated the initial hypothesis that it is feasible to recover REEs from real metal mining waste by phytoextraction and that the performance of this technology can be significantly improved by applying electric current, especially of the AC type, which increased REE accumulation in ryegrass in the range 57-68% as compared to that of the treatment without electric field application.

5.
Front Immunol ; 15: 1328707, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38361917

RESUMO

Salmonella enterica serovar Typhimurium expresses two type III secretion systems, T3SS1 and T3SS2, which are encoded in Salmonella pathogenicity island 1 (SPI1) and SPI2, respectively. These are essential virulent factors that secrete more than 40 effectors that are translocated into host animal cells. This study focuses on three of these effectors, SlrP, SspH1, and SspH2, which are members of the NEL family of E3 ubiquitin ligases. We compared their expression, regulation, and translocation patterns, their role in cell invasion and intracellular proliferation, their ability to interact and ubiquitinate specific host partners, and their effect on cytokine secretion. We found that transcription of the three genes encoding these effectors depends on the virulence regulator PhoP. Although the three effectors have the potential to be secreted through T3SS1 and T3SS2, the secretion of SspH1 and SspH2 is largely restricted to T3SS2 due to their expression pattern. We detected a role for these effectors in proliferation inside fibroblasts that is masked by redundancy. The generation of chimeric proteins allowed us to demonstrate that the N-terminal part of these proteins, containing the leucine-rich repeat motifs, confers specificity towards ubiquitination targets. Furthermore, the polyubiquitination patterns generated were different for each effector, with Lys48 linkages being predominant for SspH1 and SspH2. Finally, our experiments support an anti-inflammatory role for SspH1 and SspH2.


Assuntos
Salmonella typhimurium , Ubiquitina-Proteína Ligases , Animais , Salmonella typhimurium/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sorogrupo , Ubiquitinação
6.
Animals (Basel) ; 14(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38338111

RESUMO

This study aimed to analyze the interest, willingness to pay, and profile of tourists participating in specific agrotourism activities linked to extensive livestock farming in order to encourage the development of those activities that are most demanded by tourists, as well as to support the proposals for improvements to promote this kind of tourism in the region of Andalusia (Spain). For this purpose, a survey was conducted, which was organized into six sections: (i) sociodemographic data, (ii) general aspects of tourism, (iii) rural tourism, (iv) livestock farming and tourism, (v) benefits of extensive livestock farming, and (vi) tourism activities linked to livestock farming. A total of 892 responses were received, out of which 753 were analyzed. The results show that the respondents are interested or motivated by the proposed activities. The most attractive activities are those related to livestock farming, which involve some kind of workshop on the production of handicrafts. Despite tourists having low-to-medium knowledge of extensive livestock farming, they all express a highly positive perception of the associated attributes. Developing strategies to enhance the willingness to pay for agrotourism activities is crucial, with the overall experience being a key element of their success.

7.
Sci Total Environ ; 912: 169543, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38145688

RESUMO

The screening of new effective metal hyperaccumulators is essential for the development of profitable phytoremediation projects in highly degraded environments such as mining areas. The goal of this research was to analyze the phytoextraction potential of the native plant Spergularia rubra to decontaminate and eventually recover metals (phytomining) from the mine tailings (belonging to an abandoned Pb/Zn Spanish mine) in which it grows spontaneously. To do so, the ability of this plant species to accumulate metals was evaluated both under natural conditions and through simple and electrokinetically assisted phytoextraction tests using alternating current and different combinations of voltage gradient (1/2 V cm-1) and application time (6/12 h per day). The complete duration of the greenhouse trial was 64 days, although alternating current was applied only during the last 14 days. The results obtained demonstrated the exceptional effectiveness of S. rubra for metal hyperaccumulation and growth without affecting toxicity in highly contaminated mining waste. Zn was the metal accumulated to a higher extent in the shoots, reaching concentrations up to 17,800 mg kg-1; Pb was mainly accumulated in the roots reaching a maximum concentration of 8709 mg kg-1. Cu and Cd were accumulated to a lesser extent but the bioconcentration factors were much >1. It has been proved that S. rubra is a hyperaccumulator species for Zn and Cd both in natural and greenhouse conditions and, very probably, Pb in wild conditions. The application of AC current did not significantly increase metal concentrations in plant tissues but it was able to increase the aerial biomass of S. rubra by 49.8 %. As a result, the phytoextraction yields of all metals were significantly improved as compared to wild conditions (up to 86 % for Zn). It could open new expectations about the economic viability of recovering high-value metals from mine tailings.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/metabolismo , Descontaminação , Chumbo/metabolismo , Poluentes do Solo/análise , Biodegradação Ambiental , Plantas/metabolismo , Metais Pesados/análise
8.
Micromachines (Basel) ; 14(11)2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-38004856

RESUMO

The electric stimulation (ES) of the cornea is a novel therapeutic approach to the treatment of degenerative visual diseases. Currently, ES is delivered by placing a mono-element electrode on the surface of the cornea that uniformly stimulates the eye along the electrode site. It has been reported that a certain degree of correlation exists between the location of the stimulated retinal area and the position of the electrode. Therefore, in this study, we present the development of a sectioned surface electrode for selective electric stimulation of the human cornea. The proposed device consists of 16 independent microelectrodes, a reference electrode, and 18 contact pads. The microelectrodes have a size of 200 µm × 200 µm, are arranged in a 4 × 4 matrix, and cover a total stimulation area of 16 mm2. The proposed fabrication process, based on surface micromachining technology and flexible electronics, uses only three materials: polyimide, aluminum, and titanium, which allow us to obtain a simplified, ergonomic, and reproducible fabrication process. The fabricated prototype was validated to laboratory level by electrical and electrochemical tests, showing a relatively high electrical conductivity and average impedance from 712 kΩ to 1.4 MΩ at the clinically relevant frequency range (from 11 Hz to 30 Hz). Additionally, the biocompatibility of the electrode prototype was demonstrated by performing in vivo tests and by analyzing the polyimide films using Fourier transform infrared spectroscopy (FTIR). The resulting electrode prototype is robust, mechanically flexible, and biocompatible, with a high potential to be used for selective ES of the cornea.

9.
Environ Res ; 238(Pt 2): 117183, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37769830

RESUMO

This work utilizes a combined biological-electrochemical technique for the in-situ removal of metals from polluted mine tailings. As the main novelty point it is proposed to use electrokinetics (EK) for the in-situ activation of a bioleaching mechanism into the tailings, in order to promote biological dissolution of metal sulphides (Step 1), and for the subsequent removal of leached metals by EK transport out of the tailings (Step 2). Mine tailings were collected from an abandoned Pb/Zn mine located in central-southern Spain. EK-bioleaching experiments were performed under batch mode using a lab scale EK cell. A mixed microbial culture of autochthonous acidophilic bacteria grown from the tailings was used. Direct current with polarity reversal vs alternate current was evaluated in Step 1. In turn, different biological strategies were used: biostimulation, bioaugmentation and the abiotic reference test (EK alone). It was observed that bioleaching activation was very low during Step 1, because it was difficult to maintain acidic pH in the whole soil, but then it worked correctly during Step 2. It was confirmed that microorganisms successfully contributed to the in-situ solubilization of the metal sulphides as final metal removal rates were improved compared to the conventional abiotic EK (best increases of around 40% for Cu, 162% for Pb, 18% for Zn, 13% for Mn, 40% for Ni and 15% for Cr). Alternate current seemed to be the best option. The tailings concentrations of Fe, Al, Cu, Mn, Ni and Pb after treatment comply with regulations, but Pb, Cd and Zn concentrations exceed the maximum values. From the data obtained in this work it has been observed that EK-bioleaching could be feasible, but some upgrades and future work must be done in order to optimize experimental conditions, especially the control of soil pH in acidic values.


Assuntos
Metais Pesados , Poluentes do Solo , Chumbo , Poluentes do Solo/análise , Metais Pesados/análise , Solo , Sulfetos
10.
Food Chem Toxicol ; 181: 114066, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37769897

RESUMO

Acrylamide is a carcinogenic chemical contaminant formed in heat-treated foods. In this study, a duplicate diet method was used to evaluate the acrylamide content of foods/meals served at breakfast and lunch in two Spanish school canteens. The dietary acrylamide intake in students was estimated within lower bound (LB) and upper bound (UB) scenarios. Biscuits exhibited the highest acrylamide values, exceeding the benchmark level established by the European Regulation 2017/2158 (350 µg/kg), followed by main courses such as stews, side dishes and bread. In the LB scenario, breakfasts accounted for the major contributors to the daily acrylamide intake (73.3%). However, lunches were the main responsible in the UB scenario (65.4%). Acrylamide exposure was estimated for three age ranges: 3-5y pre-school children (0.59 and 0.92 µg/kg body weight/day), 6-9y children (0.43 and 0.67 µg/kg body weight/day) and 10-12y early adolescents (0.28 and 0.44 µg/kg body weight/day). Margins of exposure for neoplastic effects ranged between 144 and 1026, which is below the reference of 10,000, indicating a health concern. The findings reveal that any diet, even one that is balanced, varied and contains foods low in acrylamide, involves an additive exposure to the contaminant that should be considered when conducting acrylamide exposure risk assessments.


Assuntos
Acrilamida , Contaminação de Alimentos , Adolescente , Humanos , Pré-Escolar , Criança , Contaminação de Alimentos/análise , Dieta , Refeições , Peso Corporal
11.
Biophys J ; 122(18): 3738-3748, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37434354

RESUMO

Upon vascular injury, platelets form a hemostatic plug by binding to the subendothelium and to each other. Platelet-to-matrix binding is initially mediated by von Willebrand factor (VWF) and platelet-to-platelet binding is mediated mainly by fibrinogen and VWF. After binding, the actin cytoskeleton of a platelet drives its contraction, generating traction forces that are important to the cessation of bleeding. Our understanding of the relationship between adhesive environment, F-actin morphology, and traction forces is limited. Here, we examined F-actin morphology of platelets attached to surfaces coated with fibrinogen and VWF. We identified distinct F-actin patterns induced by these protein coatings and found that these patterns were identifiable into three classifications via machine learning: solid, nodular, and hollow. We observed that traction forces for platelets were significantly higher on VWF than on fibrinogen coatings and these forces varied by F-actin pattern. In addition, we analyzed the F-actin orientation in platelets and noted that their filaments were more circumferential when on fibrinogen coatings and having a hollow F-actin pattern, while they were more radial on VWF and having a solid F-actin pattern. Finally, we noted that subcellular localization of traction forces corresponded to protein coating and F-actin pattern: VWF-bound, solid platelets had higher forces at their central region while fibrinogen-bound, hollow platelets had higher forces at their periphery. These distinct F-actin patterns on fibrinogen and VWF and their differences in F-actin orientation, force magnitude, and force localization could have implications in hemostasis, thrombus architecture, and venous versus arterial thrombosis.


Assuntos
Hemostáticos , Fator de von Willebrand , Fator de von Willebrand/metabolismo , Fibrinogênio/metabolismo , Plaquetas/metabolismo , Actinas/metabolismo , Tração , Glicoproteínas da Membrana de Plaquetas/metabolismo , Hemostáticos/metabolismo , Citoesqueleto de Actina/metabolismo
12.
Environ Microbiol Rep ; 15(6): 512-529, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37482917

RESUMO

This work proves the feasibility of dechlorinating 2,4-D, a customary commercial herbicide, using cathodic electrocatalysis driven by the anodic microbial electrooxidation of sodium acetate. A set of microbial electrochemical systems (MES) were run under two different operating modes, namely microbial fuel cell (MFC) mode, with an external resistance of 120 Ω, or microbial electrolysis cell (MEC) mode, by supplying external voltage (0.6 V) for promoting the (bio)electrochemical reactions taking place. When operating the MES as an MFC, 32% dechlorination was obtained after 72 h of treatment, which was further enhanced by working under MEC mode and achieving a 79% dechlorination. In addition, the biodegradability (expressed as the ratio BOD/COD) of the synthetic polluted wastewater was tested prior and after the MES treatment, which was improved from negative values (corresponding to toxic effluents) up to 0.135 in the MFC and 0.453 in the MEC. Our MES approach proves to be a favourable option from the point of view of energy consumption. Running the system under MFC mode allowed to co-generate energy along the dechlorination process (-0.0120 kWh mol-1 ), even though low removal rates were attained. The energy input under MEC operation was 1.03 kWh mol-1 -a competitive value compared to previous works reported in the literature for (non-biological) electrochemical reactors for 2,4-D electrodechlorination.


Assuntos
Fontes de Energia Bioelétrica , Águas Residuárias , Ácido 2,4-Diclorofenoxiacético , Eletrodos
13.
Chem Mater ; 35(11): 4435-4448, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37332680

RESUMO

This work reports on an alternative and advantageous procedure to attain VO2-based thermochromic coatings on silicon substrates. It involves the sputtering of vanadium thin films at glancing angles and their subsequent fast annealing in an air atmosphere. By adjusting thickness and porosity of films as well as the thermal treatment parameters, high VO2(M) yields were achieved for 100, 200, and 300 nm thick layers treated at 475 and 550 °C for reaction times below 120 s. Comprehensive structural and compositional characterization by Raman spectroscopy, X-ray diffraction, and scanning-transmission electron microscopies combined with analytical techniques such as electron energy-loss spectroscopy bring to the fore the successful synthesis of VO2(M) + V2O3/V6O13/V2O5 mixtures. Likewise, a 200 nm thick coating consisting exclusively of VO2(M) is also achieved. Conversely, the functional characterization of these samples is addressed by variable temperature spectral reflectance and resistivity measurements. The best results are obtained for the VO2/Si sample with changes in reflectance of 30-65% in the near-infrared at temperatures between 25 and 110 °C. Similarly, it is also proven that the achieved mixtures of vanadium oxides can be advantageous for certain optical applications in specific infrared windows. Finally, the features of the different structural, optical, and electrical hysteresis loops associated with the metal-insulator transition of the VO2/Si sample are disclosed and compared. These remarkable thermochromic performances hereby accomplished highlight the suitability of these VO2-based coatings for applications in a wide range of optical, optoelectronic, and/or electronic smart devices.

14.
Heliyon ; 9(6): e17138, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37360107

RESUMO

Metal-organic frameworks (MOFs) have been an excellent platform for carbon dioxide reduction reactions (CO2RR). In this work, the feasibility of electrochemical reduction of CO2 to obtain C2-deep value-added products was investigated by the preparation of Mg-containing MOF-74 samples combined with transition metal cations (Ni2+, Co2+ and Zn2+). The prepared MOFs were used as electrocatalysts in CO2RR. Chronoamperometric analysis coupled to ATR-FTIR spectroscopy was employed to characterize the CO2 reduction products and subsequently via 1H NMR. Although an isostructural crystalline structure was observed in all synthesized MOFs, the pore diameter distribution was significantly affected due to the Mg coordination along with each transition metal nuclei with the organic ligand to form the MOF-74. Our results showed that Mg-containing MOF-74 electrocatalysts combined with Ni, Co and Zn ions successfully reduced CO2 to C2-deep products, while the monometallic Mg-MOF-74 showed only CO2 mineralization. An ester acetate, isopropyl alcohol, and formic acid were produced by Mg/Ni-MOF-74; isopropyl alcohol was provided by Mg/Co-MOF-74, and ethanol was generated by Mg/Zn-MOF-74. We observed that the change of the transition cation was a key factor in the selectivity of the obtained products, while the degree of Mg ions effectively incorporated into the MOF structure tuned the porosity and the electrocatalytic activity. Among them, Mg/Zn-MFOF-74 showed the highest Mg content loaded after synthesis and thus the most favorable electrocatalytic behavior towards CO2 reduction.

15.
Int J Mol Sci ; 24(9)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37176110

RESUMO

Type III secretion systems are found in many Gram-negative pathogens and symbionts of animals and plants. Salmonella enterica has two type III secretion systems associated with virulence, one involved in the invasion of host cells and another involved in maintaining an appropriate intracellular niche. SrfJ is an effector of the second type III secretion system. In this study, we explored the biochemical function of SrfJ and the consequences for mammalian host cells of the expression of this S. enterica effector. Our experiments suggest that SrfJ is a glucosylceramidase that alters the lipidome and the transcriptome of host cells, both when expressed alone in epithelial cells and when translocated into macrophages in the context of Salmonella infection. We were able to identify seventeen lipids with higher levels and six lipids with lower levels in the presence of SrfJ. Analysis of the forty-five genes, the expression of which is significantly altered by SrfJ with a fold-change threshold of two, suggests that this effector may be involved in protecting Salmonella from host immune defenses.


Assuntos
Salmonella typhimurium , Sistemas de Secreção Tipo III , Animais , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Salmonella typhimurium/metabolismo , Transcriptoma , Glucosilceramidase/genética , Lipidômica , Lipídeos , Proteínas de Bactérias/metabolismo , Mamíferos/metabolismo
16.
Stroke ; 54(7): 1875-1887, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37226775

RESUMO

BACKGROUND: Respiratory and urinary tract infections are frequent complications in patients with severe stroke. Stroke-associated infection is mainly due to opportunistic commensal bacteria of the microbiota that may translocate from the gut. We investigated the mechanisms underlying gut dysbiosis and poststroke infection. METHODS: Using a model of transient cerebral ischemia in mice, we explored the relationship between immunometabolic dysregulation, gut barrier dysfunction, gut microbial alterations, and bacterial colonization of organs, and we explored the effect of several drug treatments. RESULTS: Stroke-induced lymphocytopenia and widespread colonization of lung and other organs by opportunistic commensal bacteria. This effect correlated with reduced gut epithelial barrier resistance, and a proinflammatory sway in the gut illustrated by complement and nuclear factor-κB activation, reduced number of gut regulatory T cells, and a shift of gut lymphocytes to γδT cells and T helper 1/T helper 17 phenotypes. Stroke increased conjugated bile acids in the liver but decreased bile acids and short-chain fatty acids in the gut. Gut fermenting anaerobic bacteria decreased while opportunistic facultative anaerobes, notably Enterobacteriaceae, suffered an expansion. Anti-inflammatory treatment with a nuclear factor-κB inhibitor fully abrogated the Enterobacteriaceae overgrowth in the gut microbiota induced by stroke, whereas inhibitors of the neural or humoral arms of the stress response were ineffective at the doses used in this study. Conversely, the anti-inflammatory treatment did not prevent poststroke lung colonization by Enterobacteriaceae. CONCLUSIONS: Stroke perturbs homeostatic neuro-immuno-metabolic networks facilitating a bloom of opportunistic commensals in the gut microbiota. However, this bacterial expansion in the gut does not mediate poststroke infection.


Assuntos
Microbioma Gastrointestinal , Pneumonia , Acidente Vascular Cerebral , Camundongos , Animais , NF-kappa B , Bactérias/genética , Acidente Vascular Cerebral/complicações , Pulmão
17.
Foods ; 12(5)2023 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36900513

RESUMO

Semi-hard pressed goat's cheese, a traditional matured cheese in Andalusia, has a residual lactose content that may affect people with intolerance to that carbohydrate. Nowadays, lactose-free dairy products are characterized by presenting a scant sensory quality, far removed from their traditional profile for their pronounced sweet and bitter taste and aroma related to Maillard reactions. The aim of this work was to make a cheese with a similar sensory profile to that of the traditional Andalusian one but without lactose. For this purpose, the doses of the enzyme lactase that would be necessary to add to the milk were investigated so that, during the manufacturing of the cheese, there would remain enough lactose for the starter cultures to trigger lactic fermentation and, in turn, to spark the cheese's own maturity processes. The results show that the combined action of lactase (0.125 g/L, 0.250 g/L, 0.5 g/L, and 1 g/L) and of the lactic bacteria reduces the final content of lactose to below 0.01%, complying with the European Authority of Food Safety's recommendations for considering the cheeses as being under the denomination "lactose-free". The physicochemical and sensory values resulting from the different batches of cheese obtained indicate that the lowest dose studied (0.125 g/L) had very similar ones to those of the control cheese.

18.
Artigo em Inglês | MEDLINE | ID: mdl-36982021

RESUMO

Chia seed (Salvia hispanica L.) is a food rich in protein, fiber, polyunsaturated fatty acids and antioxidants. Consequently, its incorporation in food formulations may be desirable from a nutritional and healthy point of view. However, there is concern regarding the formation of process contaminants when they are subjected to thermal processing. The objective of this study was to incorporate different amounts of ground chia seeds in a biscuit model to evaluate the effect on the antioxidant capacity and formation of acrylamide and furfurals. Seven standard "Maria-type" biscuit formulations were prepared, replacing wheat flour with different amounts of ground chia seeds (defatted and non-defatted), from 0% (control biscuit) to 15% (respect to total solids in the recipe). Samples were baked at 180 °C for 22 min. Compared with the control biscuit, chia formulations increased the content of nutrients, antioxidant capacity (ABTS) and phenolic compounds (Folin-Ciocalteau method) but also doubled acrylamide levels and even raised more than 10 times furanic compound concentrations. Results indicate that the use of chia seeds as ingredients in new cereal-based formulations would improve the nutritional profile but also increase the occurrence of chemical process contaminants. This paradox should be carefully considered in the context of risk/benefit analysis.


Assuntos
Antioxidantes , Grão Comestível , Grão Comestível/química , Antioxidantes/química , Farinha/análise , Triticum , Sementes/química , Acrilamidas/análise
19.
Food Res Int ; 164: 112357, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36737945

RESUMO

Breading is a culinary technique widespread throughout the world. Deep-frying breaded foods forms a palatable crust but also promotes the formation of compounds of toxicological relevance. The influence of the composition of breadcrumbs on the risk associated with the formation of acrylamide, hydroxymethylfurfural (HMF), and furfural was investigated in a deep-fried breadcrumb coating model. Commercial (CBC) and homemade (HBC) wheat-based breadcrumbs were characterized by the reducing sugars and the asparagine content among other parameters (moisture, pH, and CIELab color). The formation of process contaminants in fried breadcrumbs were not influenced by their initial content, but they were affected by the precursors level. The HMF content was significantly higher (1.4 times) in fried HBC (172 mg/kg) than in CBC (120 mg/kg). By contrast, the acrylamide content was 3 times higher in fried CBC (332 µg/kg) than in HBC (111 µg/kg). Multivariate analysis shows that asparagine is the limiting factor for acrylamide formation, and the reducing sugar content is the main determinant for the formation of furanic compounds. A signal value of 463 µg/kg is proposed for the acrylamide content in the coating of deep-fried breaded foods. The reducing sugars and asparagine content in breadcrumb coatings should be considered when designing breaded foods, thereby reducing the formation and consequently the dietary exposure to these potentially harmful compounds.


Assuntos
Asparagina , Culinária , Culinária/métodos , Triticum/química , Açúcares , Acrilamidas
20.
ACS Appl Mater Interfaces ; 15(6): 8624-8635, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36724387

RESUMO

Incorporating an intentional strain compensating InSb interface (IF) layer in InAs/GaSb type-II superlattices (T2SLs) enhances device performance. But there is a lack of studies that correlate this approach's optical and structural quality, so the mechanisms by which this improvement is achieved remain unclear. One critical issue in increasing the performance of InAs/GaSb T2SLs arises from the lattice mismatch between InAs and GaSb, leading to interfacial strain in the structure. Not only that but also, since each side of the InAs/GaSb heterosystem does not have common atoms, there is a possibility of atomic intermixing at the IFs. To address such issues, an intentional InSb interfacial layer is commonly introduced at the InAs-on-GaSb and GaSb-on-InAs IFs to compensate for the strain and the chemical mismatches. In this report, we investigate InAs/GaSb T2SLs with (Sample A) and without (Sample B) InSb IF layers emitting in the mid-wavelength infrared (MWIR) through photoluminescence (PL) and band structure simulations. The PL studies indicate that the maximum PL intensity of Sample A is 1.6 times stronger than that of Sample B. This could be attributed to the effect of migration-enhanced epitaxy (MEE) growth mode. Band structure simulations understand the impact of atomic intermixing and segregation at T2SL IFs on the bandgap energy and PL intensity. It is observed that atomic intermixing at the IFs changes the bandgap energy and significantly affects the wave function overlap and the optical property of the samples. Transmission electron microscopy (TEM) measurements reveal that the T2SL IFs in Sample A are very rough compared to sharp IFs in Sample B, indicating a high possibility of atomic intermixing and segregation. Based on these results, it is believed that high-quality heterostructure could be achieved by controlling the IFs to enhance its structural and compositional homogeneities and the optical properties of the T2SLs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...