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1.
Food Chem ; 336: 127625, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32771897

RESUMO

The solubility of carbon dioxide (CO2) in the moisture and protein components of cheese matrices and the influence of changing pH, salt and temperature levels remains unclear. In this study, model casein matrices were prepared, by renneting of micellar casein concentrate (MCC), with modulation of salt and pH levels by adding salt and glucono delta-lactone, respectively, to the MCC solutions prior to renneting. Different moisture-to-protein levels were achieved by freeze-drying, incubation of samples at different relative humidities, or by applying varying pressures during gel manufacture. The CO2 solubility of samples decreased linearly with both increasing temperature and salt-in-moisture content, whereas solubility of CO2 increased with increasing pH. A non-linear relationship was observed between CO2 solubility and the moisture-to-protein ratio of experimental samples. Overall, such knowledge may be applied to improve the quality and consistency of eye-type cheese, and in particular to avoid development of undesirable slits and cracks.


Assuntos
Dióxido de Carbono/química , Caseínas/química , Cloreto de Sódio/química , Água/química , Queijo/análise , Concentração de Íons de Hidrogênio , Pressão Parcial , Solubilidade , Temperatura
2.
Sci Rep ; 10(1): 13875, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807805

RESUMO

Respiratory protection is key in infection prevention of airborne diseases, as highlighted by the COVID-19 pandemic for instance. Conventional technologies have several drawbacks (i.e., cross-infection risk, filtration efficiency improvements limited by difficulty in breathing, and no safe reusability), which have yet to be addressed in a single device. Here, we report the development of a filter overcoming the major technical challenges of respiratory protective devices. Large-pore membranes, offering high breathability but low bacteria capture, were functionalized to have a uniform salt layer on the fibers. The salt-functionalized membranes achieved high filtration efficiency as opposed to the bare membrane, with differences of up to 48%, while maintaining high breathability (> 60% increase compared to commercial surgical masks even for the thickest salt filters tested). The salt-functionalized filters quickly killed Gram-positive and Gram-negative bacteria aerosols in vitro, with CFU reductions observed as early as within 5 min, and in vivo by causing structural damage due to salt recrystallization. The salt coatings retained the pathogen inactivation capability at harsh environmental conditions (37 °C and a relative humidity of 70%, 80% and 90%). Combination of these properties in one filter will lead to the production of an effective device, comprehensibly mitigating infection transmission globally.


Assuntos
Filtros de Ar/microbiologia , Antibacterianos/química , Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Máscaras/microbiologia , Membranas Artificiais , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Dispositivos de Proteção Respiratória/microbiologia , Cloreto de Sódio/química , Aerossóis , Antibacterianos/farmacologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Cristalização , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Temperatura Alta , Humanos , Umidade , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Cloreto de Sódio/farmacologia
3.
J Food Sci ; 85(9): 2852-2856, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32839974

RESUMO

An in-depth understanding of mass transfer during brining process is important for improving the quality and characteristics of meat products. In this study, a fitted equation of time and NaCl concentrations in the aqueous phase of beef was established to calculate the NaCl diffusion coefficient for simulation. A three-dimensional simulating model of mass transfer was developed to evaluate the NaCl diffusion in beef during brining process. And the validity of this simulating model was verified by comparing the NaCl concentrations evaluated by the numerical simulation simulated with the experimental measurements. The results indicated that the power function time variant equation can predict NaCl concentrations (R2 = 0.995) and accurately calculate the NaCl diffusion coefficient (8.46 × 10-10 m2 /s). The simulating model visually showed the NaCl diffusion in beef during brining process. Therefore, this research provided a new method for predicting the NaCl diffusion in realistic meat processing. PRACTICAL APPLICATION: This research gives a new method for predicting the NaCl diffusion in meat product. The method accurately evaluated NaCl concentrations in beef at different brining time and clearly showed NaCl diffusion in beef during brining process, which could be helpful in reducing the cost and the complexity of detecting NaCl concentrations in meat during brining process.


Assuntos
Carne Vermelha/análise , Cloreto de Sódio/química , Animais , Bovinos , Difusão , Conservação de Alimentos/métodos , Produtos da Carne/análise , Sais/análise
4.
Food Chem ; 333: 127425, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683254

RESUMO

Zero-salted yellow alkaline noodles (YAN) were immersed in solutions of resistant starch HYLON™ VII (HC) or fruit coating Semperfresh™ (SC) containing a range of salt (NaCl) between 10 and 30% (w/v). The objective was to evaluate the effect of salt-coatings on the textural, handling, cooking, and sensory properties of YAN. Increasing salt in the coatings caused a reduction in optimum cooking time, cooking loss and increase in cooking yield. The mechanical and textural parameters, sensory hardness, springiness and overall sensory acceptability of the salt-coated noodles however decreased with increasing salt application. HC-Na10 and SC-Na10 showed the highest textural and mechanical parameters, sensory hardness and springiness. The differences in the parameters were attributed mainly to the water absorption properties of starch that was affected by salt application. Thus, the quality of salt-coated noodles was dependent mainly on the amounts of salt applied in the coatings rather than on the types of coatings used.


Assuntos
Ar , Culinária , Dessecação/métodos , Farinha/análise , Fenômenos Mecânicos , Cloreto de Sódio/química , Paladar , Cor , Qualidade dos Alimentos , Dureza , Concentração de Íons de Hidrogênio , Amido/química
5.
Food Chem ; 332: 127414, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615379

RESUMO

The reasons for the change in the water retention capability of salted pork caused by potassium chloride (KCl) instead of sodium chloride (NaCl) were investigated. Accompanied by the gradually increased substitution rate of KCl, the oxidative degradation of protein, water content, water activity (aw), gap, as well as water loss in salted pork were increased, and the results showed significant differences (p < 0.05). LF-NMR results indicated that NaCl was replaced by KCl, which can observably increased the mobility of water in the salted pork (p < 0.05). All indexes showed excellent correlation. NaCl was replaced by KCl, which affected the water retention capability of salted pork, because K+ promoted changes in the meat's physicochemical properties. The KCl replacement group presented higher water content, while displayed lower water retention capability.


Assuntos
Carne/análise , Cloreto de Potássio/química , Água/química , Animais , Manipulação de Alimentos , Espectroscopia de Ressonância Magnética , Oxirredução , Proteínas/química , Cloreto de Sódio/química , Suínos
6.
PLoS One ; 15(7): e0235225, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649660

RESUMO

Freshwater wetlands of the temperate north are exposed to a range of pollutants that may alter their function, including nitrogen (N)-rich agricultural and urban runoff, seawater intrusion, and road salt contamination, though it is largely unknown how these drivers of change interact with the vegetation to affect wetland carbon (C) fluxes and microbial communities. We implemented a full factorial mesocosm (378.5 L tanks) experiment investigating C-related responses to three common wetland plants of eastern North America (Phragmites australis, Spartina pectinata, Typha latifolia), and four water quality treatments (fresh water control, N, road salt, sea salt). During the 2017 growing season, we quantified carbon dioxide (CO2) and methane (CH4) fluxes, above- and below-ground biomass, root porosity, light penetration, pore water chemistry (NH4+, NO3-, SO4-2, Cl-, DOC), soil C mineralization, as well as sediment microbial communities via 16S rRNA gene sequencing. Relative to freshwater controls, N enrichment stimulated plant biomass, which in turn increased CO2 uptake and reduced light penetration, especially in Spartina stands. Root porosity was not affected by water quality, but was positively correlated with CH4 emissions, suggesting that plants can be important conduits for CH4 from anoxic sediment to the atmosphere. Sediment microbial composition was largely unaffected by N addition, whereas salt amendments induced structural shifts, reduced sediment community diversity, and reduced C mineralization rates, presumably due to osmotic stress. Methane emissions were suppressed by sea salt, but not road salt, providing evidence for the additional chemical control (SO4-2 availability) on this microbial-mediated process. Thus, N may have stimulated plant activity while salting treatments preferentially enriched specific microbial populations. Together our findings underpin the utility of combining plant and microbial responses, and highlight the need for more integrative studies to predict the consequences of a changing environment on freshwater wetlands.


Assuntos
Microbiota/fisiologia , Nitrogênio/química , Plantas/metabolismo , Cloreto de Sódio/química , Solo/química , Ciclo do Carbono , Connecticut , Água Doce/química , Sedimentos Geológicos/microbiologia , Nitrogênio/análise , Cloreto de Sódio/análise , Microbiologia do Solo , Qualidade da Água , Áreas Alagadas
7.
Food Chem ; 333: 127525, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683262

RESUMO

The consumption of halophytes as healthy gourmet food has increased considerably in the past few years. However, knowledge on the nutritional profile of domesticated halophytes is scarce and little is known on which cultivation conditions can produce plants with the best nutritional and functional properties. In this context, Salicornia ramosissima J. Woods was cultivated in six different salt concentrations, ranging from 35 to 465 mM of NaCl. Both the nutritional profile, the antioxidant capacity, and microbial quality of the produced plants were evaluated including minerals and vitamins. Salt has a marked effect on growth, which decreases for salinities higher than 110 mM. Nonetheless, plants cultivated with intermediate levels of salinity (110 and 200 mM) revealed better antioxidant status with higher amounts of phenolic compounds. Overall, results from this paper indicated that soilless culture systems using low-intermediate salinities produces S. ramosissima plants fit for commercialization and human consumption.


Assuntos
Antioxidantes/química , Chenopodiaceae/química , Cloreto de Sódio/química , Bactérias/isolamento & purificação , Carotenoides/análise , Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/microbiologia , Cromatografia Líquida de Alta Pressão , Fungos/isolamento & purificação , Valor Nutritivo , Fenóis/química , Vitaminas/análise
8.
J Chromatogr A ; 1623: 461204, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505292

RESUMO

Deep eutectic solvents (DESs) were used as an extractant for the determination of pyrethroids in environmental water and tea beverage samples. Three different acids were chosen as hydrogen bond donors for preparation of DESs, and decanoic acid was optimal because of its high recovery. Factors affecting relative recovery were optimized individually, including salt addition, surfactant addition, extraction temperature, DES amount, and sample volume etc. Under the optimized experimental conditions, the relative recovery of pyrethroids was from 89.3% to 97.7%, with relative standard deviation (RSD) values ranging from 1.75% to 2.73%. The linear correlation coefficient ranged from 0.9981 to 0.9992, and the linear range was between 1.9 and 500 µg/L. Based on a signal-to-noise ratio (S/N) of 3:1, the limit of detection (LOD) values were 0.56 to 1.24 µg/L. The enrichment factor ranged from 92 to 105. In conclusion, good extraction efficiency was achieved in tea beverage samples under the optimized conditions.


Assuntos
Bebidas , Emulsões/química , Interações Hidrofóbicas e Hidrofílicas , Microextração em Fase Líquida/métodos , Piretrinas/análise , Solventes/química , Chá/química , Cromatografia Líquida de Alta Pressão/métodos , Limite de Detecção , Cloreto de Sódio/química , Tensoativos/química , Temperatura , Água/química
9.
J Chromatogr A ; 1624: 461264, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540086

RESUMO

Gas-liquid chromatography is an effective method to determine infinite dilution activity coefficients (γ∞). Wall-coated open-tubular (WCOT) column which offers more advantages over packed column should be a preferable column type; however, the small carrier gas flow rate and stationary phase amount in WCOT columns limit its application in the determination of γ∞. Mathematical strategy made some progress to avoid the quantification problem in the determination of γ∞ by static-wall-coated open-tubular (SWCOT) columns. However, the previously reported strategy was based on the assumption that SWCOT column was geometrically an ideal hollow cylinder, which indeed deviates from the reality. In this study, without that assumption, we derived a new microgeometry-independent equation by using the relationship between the hold-up volume (VM) and the volume of stationary phase (VL), and used it to measure the γ∞ of various organic solutes in two ionic liquids (ILs) 1­butyl­3-methylimidazolium dicyanamide and 1,3-dibutyronitrile-imidazolium bis((trifluoromethyl)sulfonyl)imide, both of which contain double cyano groups in the anion or cation. Phase loading study was adopted to eliminate the influence of interfacial adsorption to partition. The infinite dilution partial molar excess enthalpy, selectivity and capacity were directly calculated from the experimental γ∞ values, and the linear solvation energy relationship (LSER) model was used to characterize the specific properties of both ILs. This new established equation will promote the application of SWCOT columns in thermodynamic measurement and benefit the fast screening of novel solvents for chemical separation processes.


Assuntos
Cromatografia Gasosa/métodos , Adsorção , Imidazóis/química , Líquidos Iônicos/química , Dióxido de Silício/química , Cloreto de Sódio/química , Soluções , Solventes , Termodinâmica
10.
Nat Commun ; 11(1): 2918, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522984

RESUMO

Coarse-graining of fully atomistic molecular dynamics simulations is a long-standing goal in order to allow the description of processes occurring on biologically relevant timescales. For example, the prediction of pathways, rates and rate-limiting steps in protein-ligand unbinding is crucial for modern drug discovery. To achieve the enhanced sampling, we perform dissipation-corrected targeted molecular dynamics simulations, which yield free energy and friction profiles of molecular processes under consideration. Subsequently, we use these fields to perform temperature-boosted Langevin simulations which account for the desired kinetics occurring on multisecond timescales and beyond. Adopting the dissociation of solvated sodium chloride, trypsin-benzamidine and Hsp90-inhibitor protein-ligand complexes as test problems, we reproduce rates from molecular dynamics simulation and experiments within a factor of 2-20, and dissociation constants within a factor of 1-4. Analysis of friction profiles reveals that binding and unbinding dynamics are mediated by changes of the surrounding hydration shells in all investigated systems.


Assuntos
Modelos Teóricos , Benzamidinas/química , Sítios de Ligação , Simulação de Dinâmica Molecular , Ligação Proteica , Cloreto de Sódio/química , Termodinâmica , Tripsina/química , Água/química
11.
J Biosci Bioeng ; 130(4): 390-396, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32591224

RESUMO

Rare ginsenoside CK was recognized as a popular functional food because of superior pharmacological activity, but it is restricted by further applications by the difficulty in preparation. In this study, deep eutectic solvent (DES)-based aqueous two-phase system (ATPS) was established to transform and extract ginsenoside CK in situ for the first time. The phase formation conditions for preparing ATPS using choline chloride-based DES were studied, and the optimal conditions for extractive bioconversion were explored using conventional single-factor experiments. The conditions for ATPS establishment were as follows: 31.9% (w/w) DES (ChCl-ethylene glycol)/24.5% (w/w) K2HPO4, 55 °C, pH 5.0. Under the optimal conditions, 75.79% product and 61.14% ß-glucosidase were recovered from the top and bottom phase, respectively. In addition, DES and ß-glucosidase can be recovered and recycled again for the next extractive bioconversion of CK. These results indicated that this green and efficient method exhibited considerable value in integrated production and extraction processes, and demonstrated the potential for obtaining highly recycled functional foods and similar products.


Assuntos
Ginsenosídeos/isolamento & purificação , Cloreto de Sódio/química , Solventes/química , Água/química , beta-Glucosidase/metabolismo , Ginsenosídeos/metabolismo , Hidrólise
12.
Food Chem ; 329: 127219, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516714

RESUMO

Plant-based proteins and polyphenols are increasingly being explored as functional food ingredients. Colloidal complexes were prepared from pea protein (PP) and grape seed proanthocyanidin (GSP) and the ability of the PP/GSP complexes to form and stabilize oil-in-water emulsions were investigated. The main interactions between PP and GSP were hydrogen bonding. The stability of PP-GSP complexes to environmental changes were studied: pH (2-9); ion strength (0-0.3 M); and temperature (30-90 °C). Emulsions produced using PP-GSP complexes as emulsifiers had small mean droplet diameters (~200 nm) and strongly negative surface potentials (~-60 mV). Compared to PP alone, PP-GSP complexes slightly decreased the isoelectric point, thermostability, and salt stability of the emulsions, but increased their storage stability. The presence of GSP gave the emulsions a strong salmon (red-yellow) color, which may be beneficial for some specific applications. These results may assist in the creation of more efficacious food-based strategies for delivering proanthocyanidins.


Assuntos
Emulsões/química , Extrato de Sementes de Uva/química , Proteínas de Ervilha/química , Ervilhas/metabolismo , Polifenóis/química , Proantocianidinas/química , Antioxidantes/química , Sítios de Ligação , Calorimetria , Extrato de Sementes de Uva/metabolismo , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Óleos/química , Concentração Osmolar , Proteínas de Ervilha/metabolismo , Polifenóis/metabolismo , Proantocianidinas/metabolismo , Cloreto de Sódio/química , Temperatura , Água/química
13.
Food Chem ; 331: 127340, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569971

RESUMO

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted and purified from the cartilages of skate and sturgeon. Their typical structure and physicochemical properties were evaluated by circular dichroism (CD), X-ray diffraction (XRD), and so on. Results showed that the extracted collagen was likely identified as collagen-II composed of three α-chains (135 kDa), with the typical peptide sequence of Gly-X-Y. It showed the collagen retained the native and intact triple helical structure, and its intensity ratio of the positive and negative absorption peaks (Rpn) was 0.19-0.25. In addition, the extracted collagen exhibited obvious self-assembly behavior with the concentration above 0.3 mg/mL, the adjustment of pH 7.4-7.6 and the NaCl concentration of 120 mmol/L. The critical aggregate mass concentrations of pepsin-soluble collagens from skate and sturgeon were 0.93 and 0.86 g/L, respectively. Therefore, collagens from skate and sturgeon cartilages have potential commercial application.


Assuntos
Cartilagem/química , Colágeno Tipo II/química , Proteínas de Peixes/química , Peixes , Aminoácidos/análise , Animais , Dicroísmo Circular , Colágeno Tipo II/análise , Produtos Pesqueiros , Proteínas de Peixes/análise , Concentração de Íons de Hidrogênio , Monossacarídeos/análise , Concentração Osmolar , Pepsina A/química , Conformação Proteica , Rajidae , Cloreto de Sódio/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
14.
Am J Infect Control ; 48(8): 883-889, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32464294

RESUMO

OBJECTIVE: The past 4 months, the emergence and spread of novel 2019 SARS-Cov-2 (COVID-19) has led to a global pandemic which is rapidly depleting supplies of personal protective equipment worldwide. There are currently over 1.6 million confirmed cases of COVID-19 worldwide which has resulted in more the 100,000 deaths. As these numbers grow daily, hospitals are being forced to reuse surgical masks in hopes of conserving their dwindling supply. Since COVID-19 will most likely have effects that last for many months, our nationwide shortage of masks poses a long term issue that must be addressed immediately. METHODS: Based on a previous study by Quan et al., a salt-based soaking strategy has been reported to enhance the filtration ability of surgical masks. We propose a similar soaking process which uses materials widely available in anyone's household. We tested this method of pretreating a variety of materials with a salt-based solution by a droplet test using fluorescently stained nanoparticles similar in size to the COVID-19 virus. RESULTS: In this study, we found that paper towels and surgical masks pretreated with the salt-based solution showed a noticeable increase in filtration of nanoparticles similar in size to the COVID-19 virus. We also show that the TWEEN20 used by Quan et al. is not a critical component for the solution, and using salt alone in solution still provides a dramatically increased level of protection. CONCLUSIONS: We believe this method will allow for healthcare workers to create a disposable added layer of protection to their surgical masks, N95s, or homemade masks by using household available products. Adoption of this method may play an essential role in ensuring the safety of healthcare workers during the COVID-19 pandemic and any pandemics that may arise in the future.


Assuntos
Infecções por Coronavirus/prevenção & controle , Filtração/métodos , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Máscaras/virologia , Pandemias/prevenção & controle , Equipamento de Proteção Individual/microbiologia , Pneumonia Viral/prevenção & controle , Betacoronavirus/patogenicidade , Pessoal de Saúde , Humanos , Cloreto de Sódio/química
15.
Ecotoxicol Environ Saf ; 199: 110678, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32402898

RESUMO

NaCl and Na2SO4 are the foremost salt compositions in coastal wetlands, while their effects on soil net nitrogen mineralization still remain unclear. Aimed at investigating the two salt compositions on soil net nitrogen mineralization, a 30-day laboratory incubation experiment was respectively conducted by adding 5‰ NaCl and Na2SO4 to incubated coastal wetland soils under aerobic conditions. Our results showed that Na2SO4 addition increased the rates of mineralization (Rmin) by an average of 33.03% and nitrification (Rnit) by 23.84% during the incubation (p < 0.05). In contrast, NaCl addition significantly reduced Rmin by 71% and Rnit by 44% at day 7 (p < 0.05). The activities of fluorescein diacetate, arylamidase and urease in Na2SO4 addition treatments were higher than those in NaCl addition treatment. These results demonstrated the ion-specific effects of salt type on nitrogen mineralization rates and enzyme activities.


Assuntos
Nitrogênio/análise , Cloreto de Sódio/química , Solo/química , Sulfatos/química , Áreas Alagadas , Aerobiose , Chenopodiaceae/crescimento & desenvolvimento , China , Nitrificação , Rios/química , Salinidade , Cloreto de Sódio/administração & dosagem , Microbiologia do Solo , Sulfatos/administração & dosagem , Urease/metabolismo
16.
J Biosci Bioeng ; 130(2): 200-204, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32389469

RESUMO

Ectoine is a zwitterionic amino acid derivative that can be naturally sourced from halophilic microorganisms. The increasing demands of ectoine in various industries have urged the researches on the cost-effective approaches on production of ectoine. Ionic liquids-based aqueous biphasic system (ILABS) was applied to recover Halomonas salina ectoine from cells hydrolysate. The 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim)BF4 was used in the ILABS and the recovery efficiency of ILABS to recover ectoine from H. salina cells lysate was evaluated by determining the effects of phase composition; pHs; crude loading and additional neutral salt (NaCl). The hydrophilic ectoine was targeted to partition to the hydrophilic salt-rich phase. A total yield (YB) of 96.32% ± 1.08 of ectoine was obtained with ILABS of phase composition of 20% (w/w) (Bmim)BF4 and 30% (w/w) sulfate salts; system pH of 5.5 when the 20% (w/w) of crude feedstock was applied to the ILABS. There was no significant enhancement on the ectoine recovery efficiency using the ILABS when NaCl was added, therefore the ILABS composition without the additional neutral salt was recommended for the primary purification of ectoine. Partition coefficient (KE) of 30.80 ± 0.42, purity (PE) of 95.82% and enrichment factor (Ef) of 1.92 were recorded with the optimum (Bmim)BF4/sulfate ILABS. These findings have provided an insight on the feasibility of recovery of intracellular biomolecules using the green solvent-based aqueous system in one single-step operation.


Assuntos
Diamino Aminoácidos/isolamento & purificação , Halomonas/química , Microbiologia Industrial/métodos , Líquidos Iônicos/química , Água/química , Imidazóis , Microbiologia Industrial/economia , Cloreto de Sódio/química
17.
Food Chem ; 326: 127016, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32428855

RESUMO

The effects of sodium tripolyphosphate (TPP), sodium pyrophosphate (PP), and NaCl at different ionic strengths on the formation of heterocyclic amines (HAs) were investigated in roasted beef patties. Six HAs (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine [PhIP], 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline [MeIQx], 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline [4,8-DiMeIQx], 2-amino-3-methylimidazo[4,5-f]quinoline [IQ], 1-methyl-9H-pyrido[3,4-b] indole [harman], and 9H-pyrido[3,4-b] indole [norharman]) were identified and quantified. The presence of 0.3% and 0.45% PP significantly increased the formation of PhIP (P < 0.05). Different levels of TPP/PP had no effect on MeIQx, 4,8-DiMeIQx, IQ, norharman, or harman (P > 0.05), but these products increased in the presence of NaCl at three ionic strengths and NaCl + 0.3% and 0.45% TPP/PP (P < 0.05). High hardness and surface temperatures were observed after treatments with NaCl and NaCl + TPP/PP. The increase in these six HAs in beef patties with the addition of polyphosphates and NaCl did not involve changes in pH, but mainly stemmed from higher surface temperatures during roasting.


Assuntos
Aminas/química , Compostos Heterocíclicos/química , Carne/análise , Carne Vermelha/análise , Cloreto de Sódio/química , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Culinária , Temperatura Alta , Espectrometria de Massas em Tandem
18.
Phys Chem Chem Phys ; 22(22): 12644-12650, 2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32458929

RESUMO

The effects of salts on protein systems are not yet fully understood. We investigated the ionic dynamics of three halide salts (NaI, NaBr, and NaCl) with two protein models, namely poly(N-isopropylacrylamide) (PNIPAM) and poly(N,N-diethylacrylamide) (PDEA), using multinuclear NMR, dispersion corrected density functional theory (DFT-D) calculations and dynamic light scattering (DLS) methods. The variation in ionic line-widths and chemical shifts induced by the polymers clearly illustrates that anions rather than cations interact directly with the polymers. From the variable temperature measurements of the NMR transverse relaxation rates of anions, which characterize the polymer-anion interaction intensities, the evolution behaviors of Cl-/Br-/I- during phase transitions are similar in each polymer system but differ between the two polymer systems. The NMR transverse relaxation rates of anions change synchronously with the phase transition of PNIPAM upon heating, but they drop rapidly and vanish about 3-4.5 °C before the phase transition of PDEA. By combining the DFT-D and DLS data, the relaxation results imply that anions escape from the interacting sites with PDEA prior to full polymer dehydration or collapse, which can be attributed to the lack of anion-NH interactions. The different dynamic evolutions of the anions in the PNIPAM and PDEA systems give us an important clue for understanding the micro-mechanism of protein folding in a complex salt aqueous solvent.


Assuntos
Acrilamidas/química , Resinas Acrílicas/química , Teoria da Densidade Funcional , Polímeros/química , Proteínas/química , Brometos/química , Difusão Dinâmica da Luz , Modelos Moleculares , Cloreto de Sódio/química , Compostos de Sódio/química , Iodeto de Sódio/química , Temperatura
19.
Food Chem ; 321: 126720, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32276149

RESUMO

Migration of N,N-Bis(2-hydroxyethyl) alkyl(C8-C18)amines from five different polypropylene capsules to Tenax® and coffee powder have been studied. A single step extraction-cleanup procedure using salting out liquid-liquid extraction (SALLE) method followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was applied. The critical parameters on the SALLE procedure such as extracting solvent, extracting volume, sample pH, salt and its concentration were optimized. The recovery values were in the range of 87.5%-106.5%. The %RSD were lower than 3.7%. The limit of detection was improved from 2.3 ng/g in Tenax® to 0.8 ng/g in coffee. The results indicated that the analyzed compounds have the potential to migrate from the polypropylene capsule containers to the coffee. In most of the cases, the migrated values were higher in Tenax® than in coffee in a range between 1.8 and 61%. One sample did not comply with the specific migration limit established by the European Commission.


Assuntos
Cápsulas/química , Café/química , Embalagem de Alimentos , Extração Líquido-Líquido/métodos , Polímeros/química , Polipropilenos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Análise de Alimentos/métodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Cloreto de Sódio/química , Espectrometria de Massas em Tandem/métodos
20.
J Appl Oral Sci ; 28: e20190516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236357

RESUMO

INTRODUCTION: This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). METHODOLOGY: Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). RESULTS: CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. CONCLUSIONS: CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Hidróxido de Cálcio/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Pirrolidinonas/farmacologia , Irrigantes do Canal Radicular/farmacologia , Análise de Variância , Animais , Cloreto de Cálcio/química , Cloreto de Cálcio/farmacologia , Hidróxido de Cálcio/química , Bovinos , Contagem de Colônia Microbiana , Combinação de Medicamentos , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Cloreto de Potássio/química , Cloreto de Potássio/farmacologia , Pirrolidinonas/química , Reprodutibilidade dos Testes , Irrigantes do Canal Radicular/química , Bicarbonato de Sódio/química , Bicarbonato de Sódio/farmacologia , Cloreto de Sódio/química , Cloreto de Sódio/farmacologia , Estatísticas não Paramétricas
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