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1.
Int J Mol Sci ; 22(5)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803113

RESUMO

Obesity is a risk factor for osteoarthritis (OA) development and progression due to an altered biomechanical stress on cartilage and an increased release of inflammatory adipokines from adipose tissue. Evidence suggests an interplay between loading and adipokines in chondrocytes metabolism modulation. We investigated the role of loading, as hydrostatic pressure (HP), in regulating visfatin-induced effects in human OA chondrocytes. Chondrocytes were stimulated with visfatin (24 h) and exposed to high continuous HP (24 MPa, 3 h) in the presence of visfatin inhibitor (FK866, 4 h pre-incubation). Apoptosis and oxidative stress were detected by cytometry, B-cell lymphoma (BCL)2, metalloproteinases (MMPs), type II collagen (Col2a1), antioxidant enzymes, miRNA, cyclin D1 expressions by real-time PCR, and ß-catenin protein by western blot. HP exposure or visfatin stimulus significantly induced apoptosis, superoxide anion production, and MMP-3, -13, antioxidant enzymes, and miRNA gene expression, while reducing Col2a1 and BCL2 mRNA. Both stimuli significantly reduced ß-catenin protein and increased cyclin D1 gene expression. HP exposure exacerbated visfatin-induced effects, which were counteracted by FK866 pre-treatment. Our data underline the complex interplay between loading and visfatin in controlling chondrocytes' metabolism, contributing to explaining the role of obesity in OA etiopathogenesis, and confirming the importance of controlling body weight for disease treatment.


Assuntos
Adipocinas/biossíntese , Apoptose , Condrócitos/metabolismo , Regulação da Expressão Gênica , Osteoartrite/metabolismo , Idoso , Células Cultivadas , Condrócitos/patologia , Feminino , Humanos , Pressão Hidrostática , Masculino , Pessoa de Meia-Idade , Nicotinamida Fosforribosiltransferase/farmacologia , Osteoartrite/patologia
2.
Am J Physiol Heart Circ Physiol ; 320(4): H1361-H1369, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33481697

RESUMO

Pulse wave velocity (PWV) is used to evaluate regional stiffness of large and medium-sized arteries. Here, we examine the feasibility and reliability of radial-digital PWV (RD-PWV) as a measure of regional stiffness of small conduit arteries and its response to changes in hydrostatic pressure. In 29 healthy subjects, we used Complior Analyse piezoelectric probes to record arterial pulse wave at the radial artery and the tip of the index. We determined transit time by second-derivative and intersecting tangents using the device-embedded algorithms and in-house MATLAB-based analyses of only reliable waves and by numerical simulation using a one-dimensional (1-D) arterial tree model coupled with a heart model. Second-derivative RD-PWV was 4.68 ± 1.18, 4.69 ± 1.21, and 4.32 ± 1.19 m/s for device-embedded, MATLAB-based, and numerical simulation analyses, respectively. Intersecting-tangent RD-PWV was 4.73 ± 1.20, 4.45 ± 1.08, and 4.50 ± 0.84 m/s for device-embedded, MATLAB-based, and numerical simulation analyses, respectively. Intersession coefficients of variation were 7.0% ± 4.9% and 3.2% ± 1.9% (P = 0.04) for device-embedded and MATLAB-based second-derivative algorithms, respectively. In 15 subjects, we examined the response of RD-PWV to changes in local hydrostatic pressure by vertical displacement of the hand. For an increase of 10 mmHg in local hydrostatic pressure, RD-PWV increased by 0.28 m/s (95% confidence interval: 0.16-0.40; P < 0.001). This study shows that RD-PWV can be used for the noninvasive assessment of regional stiffness of small conduit arteries. This finding allows for an integrated approach for assessing arterial stiffness gradient from the aorta to medium-sized arteries and now to small conduit arteries.NEW & NOTEWORTHY The interaction between the stiffness of various arterial segments is important in understanding the behavior of pressure and flow waves along the arterial tree. In this article, we provide a novel and noninvasive method of assessing the regional stiffness of small conduit arteries using the same piezoelectric sensors used for determination of pulse wave velocity over large- and medium-sized arteries. This development allows for an integrated approach for studying arterial stiffness gradient.


Assuntos
Pressão Arterial , Dedos/irrigação sanguínea , Análise de Onda de Pulso , Artéria Radial/fisiologia , Rigidez Vascular , Adulto , Algoritmos , Estudos Transversais , Estudos de Viabilidade , Feminino , Humanos , Pressão Hidrostática , Masculino , Pessoa de Meia-Idade , Paris , Valor Preditivo dos Testes , Análise de Onda de Pulso/instrumentação , Quebeque , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Fatores de Tempo
3.
J Sci Food Agric ; 101(1): 74-81, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32609872

RESUMO

BACKGROUND: The consumption of vegetable juices has increased due to their characteristics such as freshness/naturalness, high nutritional value, low in calories, and for being a convenient way of consuming bioactive compounds. High hydrostatic pressure (HPP), which has been mainly used to replace thermal processing, is now also being successfully applied as extraction technology to recover bioactive compounds from herbs. The present work aimed to evaluate the effect of supplementation of carrot juice with winter savory leaf aqueous extract on the final juice characteristics. RESULTS: The extract was added to raw carrot juice (1.0 mg mL-1 ), which was then submitted to HPP and stored for 15 days under refrigeration. Microbial analyses were performed during storage time, as also were analyzed the physicochemical properties such as pH, colour, bioactive compound concentration and antioxidant activity. Supplemented juices presented lower microbial counts than the non-supplemented ones, and, generally, did not present significant changes (P > 0.05) in pH or colour. Concerning the total phenolics and total flavonoids, as well as antioxidant activity, the values were generally higher (P < 0.05) in supplemented juices, which was proven by the high correlation found between total phenolics and ABTS●+ and FRAP assays. CONCLUSIONS: These data suggest that the addition of winter savory leaf extract in carrot juice treated with HPP can effectively improve microbial safety throughout refrigerated storage as well as antioxidant activity, without risking other characteristics of the juice, such as the colour or the acidity. © 2020 Society of Chemical Industry.


Assuntos
Daucus carota/química , Aditivos Alimentares/análise , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Extratos Vegetais/análise , Satureja/química , Antioxidantes/análise , Manipulação de Alimentos/instrumentação , Manipulação de Alimentos/métodos , Concentração de Íons de Hidrogênio , Pressão Hidrostática , Valor Nutritivo , Folhas de Planta/química
4.
Chemosphere ; 262: 128102, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182125

RESUMO

Novel pectin derived from sweet potato residue was modified by high hydrostatic pressure (HHP)-assisted pectinase and then used for Pb2+ removal from aqueous solutions. The removal characteristics and mechanisms were also investigated. Results showed that modified sweet potato pectin exhibited greater adsorption performances for Pb2+ than that of natural ones, and showed excellent eco-friendly properties and good potential for adsorption of some other heavy metals (such as Cu2+). The adsorption curves were much more conformed to Langmuir model, and the highest capacity for Pb2+ adsorption was 263.15 mg/g with 1.00% pectin at pH 7. Chemical adsorption process of pectin for Pb2+ absorption involved O-containing functional groups (O-H, COO-), cation exchange, and along with electrostatic interactions. Overall, the results in this study indicated that sweet potato pectin modified with HHP-assisted pectinase had the potential to become an environmentally friendly coagulant-flocculant agent for the heavy metal adsorption, especially for Pb2+.


Assuntos
Pressão Hidrostática , Ipomoea batatas/química , Chumbo/análise , Pectinas/química , Poligalacturonase/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Pectinas/isolamento & purificação , Águas Residuárias/química
5.
Food Chem ; 338: 128117, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091985

RESUMO

Sugars are critical components of fruit juice. The binding of sugars and aroma compounds may affect the release of flavor in juices. In this study, the effects of sucrose, glucose, and fructose on the release of active aroma compounds in fresh and high hydrostatic pressure-processed (HPP) Tainong mango juice were evaluated. Using gas chromatography-mass spectrometry/olfactometry and odor activity values, four volatiles were identified as active aroma compounds in fresh and HPP mango juice. Furthermore, Fourier transform infrared spectroscopy and isothermal titration calorimetry illustrated that the sugar-volatile interaction was hydrophobically-driven, with hydrogen bonding to some extent. As the concentrations of sugar were increased in the fresh juice, a significant change in the release of active volatiles occurred, while HPP juice showed stronger retention of the active volatiles. The results suggest that high hydrostatic pressure processing maintained the freshness of mango juice flavor by strengthening aroma retention within the juice matrix.


Assuntos
Manipulação de Alimentos , Sucos de Frutas e Vegetais/análise , Mangifera/química , Odorantes/análise , Açúcares/química , Cromatografia Gasosa-Espectrometria de Massas , Pressão Hidrostática , Paladar
6.
Int J Food Microbiol ; 339: 109013, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33340943

RESUMO

Hepatitis E virus (HEV) is the causative agent of acute and chronic hepatitis in humans. The zoonotic HEV genotype 3 is the main genotype in Europe. The foodborne transmission via consumption of meat and meat products prepared from infected pigs or wild boars is considered the major transmission route of this genotype. High hydrostatic pressure processing (HPP) is a technique, which can be used for inactivation of pathogens in food. Here, preparations of a cell culture-adapted HEV genotype 3 strain in phosphate-buffered saline (PBS) were subjected to HPP and the remaining infectivity was titrated in cell culture by counting fluorescent foci of replicating virus. A gradual decrease in infectivity was found by application of 100 to 600 MPa for 2 min. At 20 °C, infectivity reduction of 0.5 log10 at 200 MPa and 1 log10 at 400 MPa were observed. Slightly higher infectivity reduction of 1 log10 at 200 MPa and 2 log10 at 400 MPa were found by application of the pressure at 4 °C. At both temperatures, the virus was nearly completely inactivated (>3.5 log10 infectivity decrease) at 600 MPa; however, low amounts of remaining infectious virus were observed in one of three replicates in both cases. Transmission electron microscopy showed disassembled and distorted particles in the preparations treated with 600 MPa. Time-course experiments at 400 MPa showed a continuous decline of infectivity from 30 s to 10 min, leading to a 2 log10 infectivity decrease at 20 °C and to a 2.5 log10 infectivity decrease at 4 °C for a 10 min pressure application each. Predictive models for inactivation of HEV by HPP were generated on the basis of the generated data. The results show that HPP treatment can reduce HEV infectivity, which is mainly dependent on pressure height and duration of the HPP treatment. Compared to other viruses, HEV appears to be relatively stable against HPP and high pressure/long time combinations have to be applied for significant reduction of infectivity.


Assuntos
Microbiologia de Alimentos , Vírus da Hepatite E/fisiologia , Pressão Hidrostática , Produtos da Carne/virologia , Inativação de Vírus , Animais , Europa (Continente) , Hepatite E/transmissão , Hepatite E/virologia , Vírus da Hepatite E/ultraestrutura , Humanos , Carne/virologia , Microscopia Eletrônica de Transmissão , Modelos Biológicos , Sus scrofa , Suínos , Temperatura
7.
Food Chem ; 337: 127790, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32799165

RESUMO

The effects of different high hydrostatic pressure (HHP) conditions on the composition, morphology, rheology, thermal behavior, color, and stability of high molecular weigh melanoidins from black garlic were investigated. Because HHP promoted Maillard reaction, HHP treatments decreased the aldehyde content from 46.76% to 11.92% but increased ketones and heterocyclic contents 4.46% to 6.66% and 9.32% to 11.55%, respectively. HHP treatments induced production of five compounds that were not present in the control sample, including 5-methyl-2(3H)-furanone, 3-methyl-2-cyclopentenone, 2,3-dihydrofuran, 2-ethylfuran, and 2-vinylfuran. The surface of HHP-treated melanoidins was rough and wrinkled, and composed of large particles compared with the control. In addition, HHP reduced viscosity of melanoidins solution at a shear rate of 1-10 s-1. Moreover, HHP improved the thermal stability and the stability under UV light of black garlic melanoidins. In general, HHP treatment enhanced the composition and structure of black garlic melanoidins and improved stability.


Assuntos
Alho/química , Polímeros/química , Pressão Hidrostática , Reologia , Viscosidade
8.
Microvasc Res ; 133: 104097, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33080248

RESUMO

This work investigates the interstitial fluid flow characteristics in a solid tumor with partial fluid leakage at the tumor surface subjected to oscillatory microvascular pressure. Solutions of the pore fluid pressure and velocity in a spherical tumor are obtained using the poroelasticity theory for small strains. It is found that partial fluid leakage at the tumor surface reduces the pore pressure drop and decreases the fluid velocity near the surface compared with those in a tumor with a fully leaking surface. Both the pore pressure and the fluid velocity decrease dramatically with an increase in the vascular frequency. The pore pressure at a vascular frequency of 1 Hz is two orders of magnitude smaller than the amplitude of the vascular pressure, and the fluid velocity at the same frequency is one order of magnitude smaller than that produced by the steady constant vascular pressure. The pore pressure amplitude may reach that of the vascular pressure under the steady state vascular pressure condition.


Assuntos
Pressão Sanguínea , Líquido Extracelular/metabolismo , Microvasos/fisiopatologia , Modelos Cardiovasculares , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Animais , Velocidade do Fluxo Sanguíneo , Elasticidade , Humanos , Pressão Hidrostática , Porosidade
9.
Nat Commun ; 11(1): 4658, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938931

RESUMO

Dimethylsulfoniopropionate (DMSP) is an important marine osmolyte. Aphotic environments are only recently being considered as potential contributors to global DMSP production. Here, our Mariana Trench study reveals a typical seawater DMSP/dimethylsulfide (DMS) profile, with highest concentrations in the euphotic zone and decreased but consistent levels below. The genetic potential for bacterial DMSP synthesis via the dsyB gene and its transcription is greater in the deep ocean, and is highest in the sediment.s DMSP catabolic potential is present throughout the trench waters, but is less prominent below 8000 m, perhaps indicating a preference to store DMSP in the deep for stress protection. Deep ocean bacterial isolates show enhanced DMSP production under increased hydrostatic pressure. Furthermore, bacterial dsyB mutants are less tolerant of deep ocean pressures than wild-type strains. Thus, we propose a physiological function for DMSP in hydrostatic pressure protection, and that bacteria are key DMSP producers in deep seawater and sediment.


Assuntos
Bactérias/genética , Bactérias/metabolismo , Água do Mar/química , Água do Mar/microbiologia , Compostos de Sulfônio/metabolismo , Bactérias/isolamento & purificação , Clorofila A/análise , Clorofila A/metabolismo , Genes Bacterianos , Sedimentos Geológicos/química , Pressão Hidrostática , Marinobacter/genética , Marinobacter/isolamento & purificação , Marinobacter/metabolismo , Metagenoma , Mutação , Oceanos e Mares , Prochlorococcus/genética , Prochlorococcus/isolamento & purificação , Prochlorococcus/metabolismo , RNA Ribossômico 16S , Sulfetos/análise , Sulfetos/metabolismo , Compostos de Sulfônio/análise , Synechococcus/genética , Synechococcus/isolamento & purificação , Synechococcus/metabolismo
10.
J Vis Exp ; (163)2020 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-32955495

RESUMO

Retinal ganglion cell (RGC) axons converge at the optic nerve head to convey visual information from the retina to the brain. Pathologies such as glaucoma, trauma, and ischemic optic neuropathies injure RGC axons, disrupt transmission of visual stimuli, and cause vision loss. Animal models simulating RGC axon injury include optic nerve crush and transection paradigms. Each of these models has inherent advantages and disadvantages. An optic nerve crush is generally less severe than a transection and can be used to assay axon regeneration across the lesion site. However, differences in crush force and duration can affect tissue responses, resulting in variable reproducibility and lesion completeness. With optic nerve transection, there is a severe and reproducible injury that completely lesions all axons. However, transecting the optic nerve dramatically alters the blood brain barrier by violating the optic nerve sheath, exposing the optic nerve to the peripheral environment. Moreover, regeneration beyond a transection site cannot be assessed without reapposing the cut nerve ends. Furthermore, distinct degenerative changes and cellular pathways are activated by either a crush or transection injury. The method described here incorporates the advantages of both optic nerve crush and transection models while mitigating the disadvantages. Hydrostatic pressure delivered into the optic nerve by microinjection completely transects the optic nerve while maintaining the integrity of the optic nerve sheath. The transected optic nerve ends are reapposed to allow for axon regeneration assays. A potential limitation of this method is the inability to visualize the complete transection, a potential source of variability. However, visual confirmation that the visible portion of the optic nerve has been transected is indicative of a complete optic nerve transection with 90-95% success. This method could be applied to assess axon regeneration promoting strategies in a transection model or investigate interventions that target the axonal compartments.


Assuntos
Axônios/fisiologia , Modelos Animais de Doenças , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Animais , Axônios/patologia , Pressão Hidrostática/efeitos adversos , Bainha de Mielina/fisiologia , Compressão Nervosa , Regeneração Nervosa/fisiologia , Traumatismos do Nervo Óptico/etiologia , Ratos , Reprodutibilidade dos Testes
11.
PLoS One ; 15(9): e0239627, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32997701

RESUMO

In spite of many decades of research, the spawning migration of the European eel Anguilla anguilla from the European coast to the Sargasso Sea remains a mystery. In particular, the role of the swimbladder as a buoyancy regulating structure is not yet understood. In this study, we exercised silver eels in a swim tunnel under elevated hydrostatic pressure. The transcriptome of gas gland tissue of these exercised eels was then compared to the known transcriptome of not exercised (control) silver eel gas gland cells. Due to the high infection rate of the eel population with the swimbladder parasite Anguillicola crassus, the comparison also included an exercised group of silver eels with a heavily damaged swimbladder, and we compared the previously published transcriptome of not exercised silver eels with a highly damaged swimbladder with the exercised group of silver eels with a heavily damaged swimbladder. The comparisons of unexercised (control) silver eels with exercised silver eels with functional swimbladder (EF), as well as with exercised silver eels with damaged swimbladder (ED), both showed a significant elevation in transcripts related to glycolytic enzymes. This could also be observed within the comparison of unexercised silver eels with a highly infected swimbladder with exercised eels with a damaged swimbladder (DED). In contrast to EF, in ED a significant elevation in transcript numbers of mitochondrial NADH dehydrogenase was observed. While in EF the transcriptional changes suggested that acid production and secretion was enhanced, in ED these changes appeared to be related to thickened tissue and thus elevated diffusion distances. The remarkable number of differentially expressed transcripts coding for proteins connected to cAMP-dependent signaling pathways indicated that metabolic control in gas gland cells includes cAMP-dependent pathways. In contrast to ED, in EF significant transcriptional changes could be related to the reconstruction of the extracellular matrix, while in ED tissue repair and inflammation was more pronounced. Surprisingly, in exercised eels hypoxia inducible transcription factor expression was elevated. In EF, a large number of genes related to the circadian clock were transcriptionally modified, which may be connected to the circadian vertical migrations observed during the spawning migration.


Assuntos
Sacos Aéreos/metabolismo , Enguias/metabolismo , Glândulas Exócrinas/metabolismo , Glicólise , Pressão Hidrostática , Migração Animal , Animais , Dióxido de Carbono/metabolismo , Enguias/fisiologia , Ácido Láctico/metabolismo , Natação , Transcriptoma
12.
Yakugaku Zasshi ; 140(9): 1095-1099, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879241

RESUMO

The lens of the eye is an avascular and anuclear tissue that serves to focus objects on the retina. Cataract is opacity within the clear lens that changes the transparency and refractive index of the lens causing significant visual impairments. These impairments can severely restrict the ability to carry out daily activities. Cataracts is common among elderly person occurring in more than 80% of patients aged 80 or older. Notably, we have recently identified key compounds that are effective against cataract formation. Presbyopia is also an ocular disease that typically develops in people over the age of 45 while affecting almost 100% of people over the age of 65. Recent research suggests that age-related changes in hydrostatic pressure of the lens controlled by Na/K ATPase contribute to the development of presbyopia. In the lens, Na/K ATPase has been shown to be regulated by transient receptor potential cation channels, vanilloid 1 (TRPV1) and 4, thus suggesting the potential role of TRPV1 and TRPV4 in the development of presbyopia. This review article summarizes data obtained from our laboratory with my colleagues highlighting the critical role of aquaporin 0 (AQP0) in maintaining a healthy lens redox environment, key molecules that delay the onset of cataract in vivo, as well as potential mechanisms of lens hydrostatic pressure control that may be associated with presbyopia.


Assuntos
Aquaporinas/fisiologia , Catarata/tratamento farmacológico , Catarata/etiologia , Desenvolvimento de Medicamentos , Proteínas do Olho/fisiologia , Pressão Hidrostática , Cristalino/metabolismo , Oxirredução , Presbiopia/etiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/fisiologia , Canais de Cátion TRPV/fisiologia
13.
PLoS One ; 15(8): e0235180, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760063

RESUMO

Nipponites is a heteromorph ammonoid with a complex and unique morphology that obscures its mode of life and ethology. The seemingly aberrant shell of this Late Cretaceous nostoceratid seems deleterious. However, hydrostatic simulations suggest that this morphology confers several advantages for exploiting a quasi-planktic mode of life. Virtual, 3D models of Nipponites mirabilis were used to compute various hydrostatic properties through 14 ontogenetic stages. At each stage, Nipponites had the capacity for neutral buoyancy and was not restricted to the seafloor. Throughout ontogeny, horizontally facing to upwardly facing soft body orientations were preferred at rest. These orientations were aided by the obliquity of the shell's ribs, which denote former positions of the aperture that were tilted from the growth direction of the shell. Static orientations were somewhat fixed, inferred by stability values that are slightly higher than extant Nautilus. The initial open-whorled, planispiral phase is well suited to horizontal backwards movement with little rocking. Nipponites then deviated from this bilaterally symmetric coiling pattern with a series of alternating U-shaped bends in the shell. This modification allows for proficient rotation about the vertical axis, while possibly maintaining the option for horizontal backwards movement by redirecting its hyponome. These particular hydrostatic properties likely result in a tradeoff between hydrodynamic streamlining, suggesting that Nipponites assumed a low energy lifestyle of slowly pirouetting in search for planktic prey. Each computed hydrostatic property influences the others in some way, suggesting that Nipponites maintained a delicate hydrostatic balancing act throughout its ontogeny in order to facilitate this mode of life.


Assuntos
Exoesqueleto/crescimento & desenvolvimento , Evolução Biológica , Cefalópodes/fisiologia , Movimento/fisiologia , Exoesqueleto/anatomia & histologia , Animais , Cefalópodes/anatomia & histologia , Pressão Hidrostática , Modelos Anatômicos
14.
Food Chem ; 333: 127530, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683264

RESUMO

Soybean protein isolate (SPI) was incubated with flaxseed gum (FG) at 60 °C for 3 days under high hydrostatic pressure (HHP 0.1-300 MPa). Results showed improvement in solubility of SPI upon glycation with FG. The maximum solubility reached 86.84% when SPI-FG was treated at pH 8.0 and 200 MPa. The occurrence, degrees and sites of SPI-FG glycation suggested that moderate pressure (100 MPa) significantly promoted Maillard reactions, but higher pressures (greater than 200 MPa) suppressed these reactions. The secondary structure of the glycated proteins varied greatly with respect to α-helix and random coil contents and vibrations of the amide II band at 200 MPa. These microstructural changes increased the solubility over a broad pH range. The conformational changes in the glycated SPI supported the improved solubility of SPI-FG. Overall, HHP represents a potential method of controlling glycation to improve protein processability and expand their applicability in the food industry.


Assuntos
Linho/química , Gomas Vegetais/química , Proteínas de Soja/química , Glicosilação , Pressão Hidrostática , Reação de Maillard , Estrutura Secundária de Proteína , Solubilidade
15.
Food Chem ; 331: 127203, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32574943

RESUMO

Effects of high hydrostatic pressure (HHP) (50, 100, 150, 200 and 250 MPa) pretreatment on water mobility and distribution, drying duration, microstructure, color, cell wall fraction and tissue structure of strawberry slices were investigated. HHP significantly increased water mobility of the strawberry slices, resulting in the reduction of drying duration by 9-24%. As the pretreatment pressure was increased, redness value and anthocyanin content continuously increased, soluble pectin (SBP) content increased and then decreased, while the contents of protopectin (PTP) and cellulose decreased. After the HHP pretreatment, chromoplasts and moisture was distributed more uniformly in the strawberry slices. Microscopy images showed the formation of microscopic holes or channels in the matrix and the breakdown of tissue structure by HHP. Results suggested HHP pretreatment disrupted the integrity of the fresh strawberry which enhanced the drying efficiency and migration of the chromoplasts during the vacuum-freeze drying process.


Assuntos
Fragaria/química , Liofilização , Antocianinas/química , Antocianinas/metabolismo , Celulose/química , Cor , Fragaria/metabolismo , Pressão Hidrostática , Espectroscopia de Ressonância Magnética , Pectinas/química , Pectinas/metabolismo , Água/química
16.
Plant Foods Hum Nutr ; 75(3): 427-433, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32572675

RESUMO

In this paper, high-hydrostatic pressure extraction (HHPE) as an emerging food processing and preservation technique constitutes an alternative to conventional thermal treatment that has been used for extraction of polyphenols from tomato peel waste generated by the canning industry. The impact of time (5 and 10 min), temperature (25, 35, 45 and 55 °C) and solvents (water, 1% HCl, 50 and 70% methanol with and without addition of HCl, and 50 and 70% ethanol), at a constant pressure of 600 MPa, has been evaluated in this paper with respect to polyphenols' yields. The results showed a significant (p < 0.05) variation in the contents of a great number of phenolic compounds in respect of the applied temperatures and solvents. On the other hand, the time invested in HHPE had no effect on polyphenols' yields. Among phenolic compounds, the p-coumaric acid (p-CA) and chlorogenic acid derivative (ChA der) are predominant, i.e., 0.57 to 67.41 mg/kg and 1.29 to 58.57 mg/kg, respectively, depending on the solvents and temperatures used. In particular, methanol (50 and 70%) at temperatures of 45 and 55 °C enhanced the recovery of polyphenols in comparison to other utilised solvents. In conclusion, this paper puts forth the theory that by applying HHPE with minimal expenditure of time, it is possible to achieve efficient production of polyphenols from low-cost tomato peel waste, generating income both for producers and agri-food industries.


Assuntos
Lycopersicon esculentum , Polifenóis , Antioxidantes , Cromatografia Líquida de Alta Pressão , Pressão Hidrostática , Extratos Vegetais , Solventes
17.
J Dairy Sci ; 103(7): 5978-5991, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32418693

RESUMO

Human milk (HM) constitutes the first immunological barrier and the main source of nutrients and bioactive components for newborns. Immune factors comprise up to 10% of the protein content in HM, where antibodies are the major components (mainly IgA, IgG, and IgM). In addition, antibacterial enzymes such as lysozyme and immunoregulatory factors such as soluble cluster of differentiation 14 (sCD14) and transforming growth factor ß2 (TGF-ß2) are also present and play important roles in the protection of the infant's health. Donor milk processed in HM banks by Holder pasteurization (HoP; 62.5°C, 30 min) is a safe and valuable resource for preterm newborns that are hospitalized, but is reduced in major immunological components due to thermal inactivation. We hypothesized that high hydrostatic pressure (HHP) and high-pressure homogenization (HPH) are 2 processes that can be used on HM to reduce total bacteria counts while retaining immunological components. We studied the effects of HHP (400, 450, and 500 MPa for 5 min applied at 20°C) and HPH (200, 250, and 300 MPa, milk inlet temperature of 20°C) applied to mature HM, on microbiological and immunological markers (IgA, IgG, IgM, sCD14, and TGF-ß2), and compared them with those of traditional HoP in HM samples from healthy donors. The HHP processing between 400 and 500 MPa at 20°C reduced counts of coliform and total aerobic bacteria to undetectable levels (<1.0 log cfu/mL) while achieving approximately 100% of immunological component retention. In particular, comparing median percentages of retention of immunological components for 450 MPa versus HoP, we found 101.5 versus 50.5% for IgA, 89.5 versus 26.0% for IgM, 104.5 versus 75.5% for IgG, 125.0 versus 72.5% for lysozyme, 50.6 versus 0.1% for sCD14, and 88.5 versus 61.1% for TGF-ß2, respectively. Regarding HPH processing, at a pressure of 250 MPa and inlet temperature of 20°C, the process showed good potential to reduce coliforms to undetectable levels and total aerobic bacteria to levels slightly above those obtained by HoP. The median percentages of retention of immunological markers for HPH versus HoP were 71.5 versus 52.0%, 71.0 versus 27.0%, 104.0 versus 66.5%, and 30.9 versus 0.2%, for IgA, IgM, IgG, and sCD14, respectively; results did not significantly differ for lysozyme and TGF-ß2. The HPH at 300 MPa produced higher inactivation of immunological components, similar to values achieved with HoP.


Assuntos
Leite Humano/imunologia , Adulto , Feminino , Humanos , Pressão Hidrostática , Bancos de Leite , Pasteurização , Temperatura , Adulto Jovem
18.
Enzyme Microb Technol ; 137: 109538, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32423674

RESUMO

Glucose oxidase (GOx) was modified by attaching phenyl groups to either carboxyl or amino side chains on the enzyme. High hydrostatic pressure (HHP) stabilized the aniline-, and benzoate-modified GOx at 69.1-80 °C compared to atmospheric pressure. At 240 MPa and 80.0 °C, the first order rate constant of inactivation kinact. of aniline-modified GOx was 20 × 10-2 min-1, or 3.7 times smaller than for the native GOx, while the kinact for benzoate-modified GOx was 26 × 10-2 min-1, or 2.8 times smaller than for the native GOx at the same temperature. Furthermore, at 240 MPa and 80.0 °C, the kinact of the aniline-modified GOx was 69 times smaller than the kinact of native GOx (1530 × 10-2 min-1) at 0.1 MPa and 80.0 °C. Similar results were obtained for benzoate-modified GOx. At each temperature in this study (25-69.1 °C), the catalytic activity of the native, aniline-, or benzoate-modified GOx increased with HHP, and reached a maximum at around 180 MPa. At 180 MPa and 69.1 °C, aniline-modified GOx produced the fastest catalytic rate, followed by benzoate-modified GOx, and then native GOx. An increase in temperature increased the activation volume of the reaction. Similarly, the activation energy increased with pressure. The combination of HHP and hydrophobic modification made GOx more thermostable and increased the effect of temperature in enzyme activity.


Assuntos
Compostos de Anilina/metabolismo , Aspergillus niger/enzimologia , Glucose Oxidase/metabolismo , Temperatura , Estabilidade Enzimática , Interações Hidrofóbicas e Hidrofílicas , Pressão Hidrostática , Cinética
19.
Food Chem ; 327: 127047, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32454269

RESUMO

For more effective using of HHP (high hydrostatic pressure) in starch processing, in this study, molecular dynamics simulation was used to explore the effects of pressure on amylose molecular conformation at the atomic level. The results shown that, firstly, high pressure decreased the intramolecular hydrogen bonds and increased the amylose-solvent hydrogen bonds, which is consistent with the process of high pressure starch gelatinization. Secondly, high pressure made amylose polymers more "stout". Meanwhile, high pressure decreased the angle of α-1,4 glycosidic linkage and increased the dihedral angles of α-1,4 glycosidic linkage, which indicates that pressure has obvious effects on amylose molecular conformation. Thirdly, high pressure made amylose polymers more stable. Moreover, in view of the results of energies, HHP may have an opposite gelatinization mechanism to heating. The results may be complementary to the existing experimental phenomena and provide theoretical guidance value for the using of HHP in starch processing.


Assuntos
Amilose/química , Simulação de Dinâmica Molecular , Ligação de Hidrogênio , Pressão Hidrostática , Conformação Molecular , Solventes/química
20.
Am J Physiol Cell Physiol ; 318(5): C969-C980, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32293931

RESUMO

The porcine lens response to a hyperosmotic stimulus involves an increase in the activity of an ion cotransporter sodium-potassium/two-chloride cotransporter 1 (NKCC1). Recent studies with agonists and antagonists pointed to a mechanism that appears to depend on activation of transient receptor potential vanilloid 1 (TRPV1) ion channels. Here, we compare responses in lenses and cultured lens epithelium obtained from TRPV1-/- and wild type (WT) mice. Hydrostatic pressure (HP) in lens surface cells was determined using a manometer-coupled microelectrode approach. The TRPV1 agonist capsaicin (100 nM) caused a transient HP increase in WT lenses that peaked after ∼30 min and then returned toward baseline. Capsaicin did not cause a detectable change of HP in TRPV1-/- lenses. The NKCC inhibitor bumetanide prevented the HP response to capsaicin in WT lenses. Potassium transport was examined by measuring Rb+ uptake. Capsaicin increased Rb+ uptake in cultured WT lens epithelial cells but not in TRPV1-/- cells. Bumetanide, A889425, and the Akt inhibitor Akti prevented the Rb+ uptake response to capsaicin. The bumetanide-sensitive (NKCC-dependent) component of Rb+ uptake more than doubled in response to capsaicin. Capsaicin also elicited rapid (<2 min) NKCC1 phosphorylation in WT but not TRPV1-/- cells. HP recovery was shown to be absent in TRPV1-/- lenses exposed to hyperosmotic solution. Bumetanide and Akti prevented HP recovery in WT lenses exposed to hyperosmotic solution. Taken together, responses to capsaicin and hyperosmotic solution point to a functional role for TRPV1 channels in mouse lens. Lack of NKCC1 phosphorylation and Rb+ uptake responses in TRPV1-/- mouse epithelium reinforces the notion that a hyperosmotic challenge causes TRPV1-dependent NKCC1 activation. The results are consistent with a role for the TRPV1-activated signaling pathway leading to NKCC1 stimulation in lens osmotic homeostasis.


Assuntos
Cristalino/metabolismo , Membro 2 da Família 12 de Carreador de Soluto/genética , Canais de Cátion TRPV/genética , Animais , Bumetanida/farmacologia , Capsaicina/farmacologia , Linhagem Celular , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Humanos , Pressão Hidrostática/efeitos adversos , Cristalino/efeitos dos fármacos , Camundongos , Camundongos Knockout , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Suínos
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