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1.
J Electrocardiol ; 82: 100-112, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38113771

RESUMO

BACKGROUND: The vectocardiogram (VCG) offers a three-dimensional view of the heart's electrical activity, yet many VCG parameters remain unexplored in diverse clinical contexts. OBJECTIVES: This study aims to explore the relationships between various VCG parameters and specific patient characteristics. METHODS: ECG signals from adults were transformed into VCGs utilizing the Kors matrix, yielding 315 parameters per patient from the P, QRS and T loops. Univariable analysis, circular statistics, and stepwise logistic regression were employed to examine the relationships between VCG parameters and factors such as age, sex, BMI, hypertension, echocardiographic ischemic heart disease (Echo-IHD), and left ventricular hypertrophy (Echo-LVH). RESULTS: We included 664 adults and considered an alpha value of 0.05 and a power of 90%. The study revealed significant associations, such as age with P loop roundness index (RI) (OR = 3.825, 95% confidence interval [95%CI] = 2.079-7.04), male sex with QRS loop RI (OR = 6.08, 95%CI = 1.835-20.153), abnormal BMI with the T loop's RI (OR = 0.544, 95%CI = 0.325-0.909), hypertension with the T loop planarity index (PI) (OR = 8.01, 95%CI = 2.134-30.117), Echo-IHD with QRS loop curvature at the 4/10th segment (OR = 7.58, 95%CI = 1.954-29.458), and Echo-LVH with the T loop lag-1/10 dihedral angle (OR = 10.3, 95%CI = 1.822-58.101). In the study, several additional VCG parameters demonstrated statistically significant, albeit smaller, associations with patient demographics and cardiovascular conditions. CONCLUSIONS: The findings enhance our understanding of the intricate relationships between VCG parameters and patient characteristics, emphasizing the potential role of VCG analysis in assessing cardiovascular diseases. These insights may guide future research and clinical applications in cardiology.


Assuntos
Doenças Cardiovasculares , Cardiopatias , Hipertensão , Isquemia Miocárdica , Adulto , Masculino , Humanos , Eletrocardiografia/métodos , Índice de Massa Corporal , Vetorcardiografia/métodos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem
2.
Int J Mol Sci ; 25(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673753

RESUMO

In the department of Boyacá, Colombia, agriculture stands as one of the primary economic activities. However, the escalating utilization of pesticides within this sector has sparked concern regarding its potential correlation with elevated risks of genotoxicity, chromosomal alterations, and carcinogenesis. Furthermore, pesticides have been associated with a broad spectrum of genetic polymorphisms that impact pivotal genes involved in pesticide metabolism and DNA repair, among other processes. Nonetheless, our understanding of the genotoxic effects of pesticides on the chromosomes (as biomarkers of effect) in exposed farmers and the impact of genetic polymorphisms (as susceptibility biomarkers) on the increased risk of chromosomal damage is still limited. The aim of our study was to evaluate chromosomal alterations, chromosomal instability, and clonal heterogeneity, as well as the presence of polymorphic variants in the GSTP1 and XRCC1 genes, in peripheral blood samples of farmers occupationally exposed to pesticides in Aquitania, Colombia, and in an unexposed control group. Our results showed statistically significant differences in the frequency of numerical chromosomal alterations, chromosomal instability, and clonal heterogeneity levels between the exposed and unexposed groups. In addition, we also found a higher frequency of chromosomal instability and clonal heterogeneity in exposed individuals carrying the heterozygous GSTP1 AG and XRCC1 (exon 10) GA genotypes. The evaluation of chromosomal alterations and chromosomal instability resulting from pesticide exposure, combined with the identification of polymorphic variants in the GSTP1 and XRCC1 genes, and further research involving a larger group of individuals exposed to pesticides could enable the identification of effect and susceptibility biomarkers. Such markers could prove valuable for monitoring individuals occupationally exposed to pesticides.


Assuntos
Instabilidade Cromossômica , Fazendeiros , Glutationa S-Transferase pi , Exposição Ocupacional , Praguicidas , Proteína 1 Complementadora Cruzada de Reparo de Raio-X , Humanos , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Glutationa S-Transferase pi/genética , Praguicidas/toxicidade , Praguicidas/efeitos adversos , Exposição Ocupacional/efeitos adversos , Masculino , Instabilidade Cromossômica/efeitos dos fármacos , Adulto , Pessoa de Meia-Idade , Feminino , Biomarcadores , Aberrações Cromossômicas/induzido quimicamente , Colômbia , Polimorfismo de Nucleotídeo Único , Predisposição Genética para Doença
3.
Br J Clin Pharmacol ; 89(2): 898-902, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36354135

RESUMO

The inhibition of cytochrome P450 (CYP) enzymes is the most frequent cause of drug-drug interactions. Many safe, inexpensive and widely available therapeutic drugs can inhibit CYP enzymes (e.g., azoles). Also, the specific potency of inhibition and the targeted CYP enzyme have been well described (e.g., itraconazole strongly inhibits CYP enzyme 3A4 and, in turn, CYP3A4 metabolizes venetoclax and ibrutinib). CYP enzyme inhibitors increase the plasma concentration of other drugs via shared metabolic pathways. We herein present the effects of inhibiting CYP enzymes with itraconazole-venetoclax for the treatment of refractory acute myeloid leukaemia, as well as itraconazole-ibrutinib to treat steroid-refractory acute graft vs. host disease in the same patient. Both of the patient's conditions responded completely. This appears to be a feasible strategy that decreases treatment costs by 75%. Previous Food and Drug Administration recommendations and clinical data support these subsequent dose reductions. Eleven months after the transplant, the patient remains in complete response and with no minimal residual disease. Another patient had been effectively treated before with CYP enzyme inhibition prior to venetoclax-itraconazole administration for orbital myeloid sarcoma. Thus, this case study furthers information on the CYP enzyme inhibition strategy when associated with another costly drug, ibrutinib. The CYP enzyme inhibition strategy could be applied to many more anticancer drugs (e.g., ruxolitinib and ponatinib) and facilitate the availability of expensive oncological treatments in low- and middle-income countries. Also, this strategy could be further generalized by using different CYP enzyme inhibitors with varied pharmacokinetic and pharmacodynamic properties (i.e., grapefruit, azoles and clarithromycin).


Assuntos
Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450 , Interações Medicamentosas , Humanos , Citocromo P-450 CYP3A/metabolismo , Inibidores das Enzimas do Citocromo P-450/uso terapêutico , Sistema Enzimático do Citocromo P-450/metabolismo , Itraconazol/farmacologia
4.
J Oncol Pharm Pract ; 29(2): 493-497, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35747932

RESUMO

CASE REPORT: We report the first case of orbital myeloid sarcoma that was successfully treated with a standard venetoclax dose of 25%. A 38-year-old man with acute myeloid leukemia (AML) post-haplo-hematopoietic stem cell transplantation (HSCT) presented with a nine-month history of progressive right proptosis and a visual acuity deficit. The patient was treated with venetoclax (100 mg orally on days 1-28), cytarabine (40 mg subcutaneously, days 1-10), and itraconazole (100 mg twice daily orally on days 1-28). MANAGEMENT AND OUTCOME: The present case report shows that using cytochrome P450 (CYP) inhibitors is a helpful strategy to reduce the cost of expensive treatments. DISCUSSION: There are limited data on the use of CYP inhibitors as a strategy to reduce the costs of expensive drugs (i.e. venetoclax). This approach has some advantages over standard dose venetoclax (400 mg/day) such as significantly reduced costs (which is relevant for patients in low-income countries). In this case, we used itraconazole-a potent CYP3A4 inhibitor-which can theoretically reduce the dose to 100 mg/day without losing serum therapeutic concentrations.


Assuntos
Leucemia Mieloide Aguda , Sarcoma Mieloide , Sarcoma , Masculino , Humanos , Adulto , Sarcoma Mieloide/tratamento farmacológico , Itraconazol/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Leucemia Mieloide Aguda/tratamento farmacológico , Sarcoma/tratamento farmacológico , Sistema Enzimático do Citocromo P-450/uso terapêutico
5.
J Thromb Thrombolysis ; 54(2): 360-366, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35471623

RESUMO

Immune thrombocytopenia (ITP) is an autoimmune disease that results from antibody-mediated platelet destruction and impaired platelet production. Novel therapies have emerged in the last decade, but 15-20% of patients will relapse or fail and require further therapy. We performed a prospective, single-arm intervention study on seven patients with chronic, persistent, or refractory ITP from the Hospital Universitario "Dr. José E González", in Monterrey, Mexico between 2015 and 2019. Eligible patients received oral oseltamivir 75 mg twice daily for 5 days and were followed up for six months. Most patients received a median of three distinct therapies (range 2-6). Four patients (57.1%) received combined therapy. The median time for any response was 55.5 days (range = 14-150). All patients responded at some point in time (ORR = 100%, six had a proportion of loss of response [PR], and one achieved [CR]). Six months after oseltamivir administration, three patients (42.9%) maintained a response, and one patient had a CR (14.3%). Oseltamivir was well tolerated with a good overall response rate and was useful for treating chronic ITP. We observed an initial increase in the number of platelets; however, this response was not maintained.


Assuntos
Púrpura Trombocitopênica Idiopática , Trombocitopenia , Humanos , Oseltamivir/uso terapêutico , Estudos Prospectivos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Trombocitopenia/tratamento farmacológico , Resultado do Tratamento
6.
Molecules ; 27(4)2022 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-35209041

RESUMO

The unstable proteins in white wine cause haze in bottles of white wine, degrading its quality. Thaumatins and chitinases are grape pathogenesis-related (PR) proteins that remain stable during vinification but can precipitate at high temperatures after bottling. The white wine protein stabilization process can prevent haze by removing these unstable proteins. Traditionally, bentonite is used to remove these proteins; however, it is labor-intensive, generates wine losses, affects wine quality, and harms the environment. More efficient protein stabilization technologies should be based on a better understanding of the main factors and mechanisms underlying protein precipitation. This review focuses on recent developments regarding the instability and removal of white wine proteins, which could be helpful to design more economical and environmentally friendly protein stabilization methods that better preserve the products´ quality.


Assuntos
Bentonita/química , Quitinases/química , Temperatura Alta , Proteínas de Plantas/química , Vitis , Vinho
7.
J Comput Chem ; 41(31): 2653-2662, 2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-32936470

RESUMO

Recently, the need of improvement of energy storage has led to the development of Lithium batteries with porous materials as electrodes. Porous Germanium (pGe) has shown promise for the development of new generation Li-ion batteries due to its excellent electronic, and chemical properties, however, the effect of lithium in its properties has not been studied extensively. In this contribution, the effect of surface and interstitial Li on the electronic properties of pGe was studied using a first-principles density functional theory scheme. The porous structures were modeled by removing columns of atoms in the [001] direction and the surface dangling bonds were passivated with H atoms, and then replaced with Li atoms. Also, the effect of a single interstitial Li in the Ge was analyzed. The transition state and the diffusion barrier of the Li in the Ge structure were studied using a quadratic synchronous transit scheme.

8.
J Dairy Res ; 86(2): 248-251, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31138340

RESUMO

The research reported in this Research Communication evaluates the effect of milk acidification on the physicochemical and sensory properties of Licor de Oro (or Gold Liqueur; LO), a traditional alcoholic beverage produced in Chiloé island, Chile, which is made by mixing milk acidified with lemon juice and alcohol at a ratio of 1.0:1.0, along with sugar and other spices. The mixture is stored for a couple of weeks and then filtered to obtain a product with a yellowish-transparent appearance, sweetness and acidic taste, milky and alcoholic notes. The lack of information regarding LO processing, mainly in the amount of acid added to the mixture, leads to products of highly variable quality. Thus, the objective of this study was to evaluate the effect of milk acidification on the physicochemical and sensory properties of LO. Raw milk was acidified using citric acid to six different pH values: 6.7 (control), 6.0, 5.3, 4.6, 3.9 and 3.2. These milk treatments were then used to make LO. A decrease of milk pH led to LO with higher levels of sensorial and titratable acidity. LO obtained at pH 6.7 and 6.0 had higher levels of total protein than other treatments, leading to excessive turbidity. In contrast, treatments made at pH ≤5.3 had a typical transparent appearance of LO. These results suggest that a minimum level of milk acidification is required to obtain LO with desired appearance and composition.


Assuntos
Bebidas Alcoólicas/análise , Leite/química , Animais , Fermentação , Concentração de Íons de Hidrogênio , Paladar
11.
Anal Chem ; 88(23): 11436-11443, 2016 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-27934094

RESUMO

Scanning electrochemical microscopy (SECM) has been widely used for the electrochemical imaging of dynamic topographical and metabolic changes in alive adherent mammalian cells. However, extracting intracellular information by SECM is challenging, since it requires redox species to travel in and out the lipid cell membrane. Herein, we present cell fixation and permeabilization approaches as an alternative tool for visualizing cell properties by SECM. With this aim, adherent cells were analyzed in the SECM feedback mode in three different conditions: (i) alive; (ii) fixed, and (iii) fixed and permeabilized. The fixation was carried out with formaldehyde and does not damage lipid membranes. Therefore, this strategy can be used for the SECM investigation of cell topography or the passive transport of the redox mediator into the cells. Additional permeabilization of the cell membrane after fixation enables the analysis of the intracellular content through the coupling of SECM with immunoassay strategies for the detection of specific biomarkers. The latter was successfully applied as an easy and fast screening approach to detect the expression of the melanoma-associated marker tyrosinase in adherent melanoma cell lines corresponding to different cancer progression stages using the SECM substrate generation-tip collection mode. The present approach is simple, fast, and reliable and can open new ways to analyze cell cultures with electrochemically based scanning probe techniques.


Assuntos
Biomarcadores Tumorais/análise , Imunoensaio , Microscopia Eletroquímica de Varredura , Monofenol Mono-Oxigenase/análise , Biomarcadores Tumorais/metabolismo , Sobrevivência Celular , Formaldeído/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Células Tumorais Cultivadas
12.
Gac Med Mex ; 152(Suppl 2): 57-65, 2016 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-27792717

RESUMO

INTRODUCTION: Autologous hematopoietic stem cell transplantation is the treatment of choice for high-risk Hodgkin's lymphoma and non-Hodgkin's lymphoma. OBJECTIVE: Compare the capacity to mobilize CD34+ cells for autologous hematopoietic stem cell transplantation using schemes with chemotherapy and without chemotherapy plus filgrastim in patients diagnosed with Hodgkin's lymphoma or non-Hodgkin's lymphoma. MATERIAL AND METHODS: The clinical records of patients with Hodgkin's lymphoma or non-Hodgkin's lymphoma who received an autologous hematopoietic stem cell transplant were analyzed retrospectively. Filgrastim alone or in combination with chemotherapy was used as mobilization scheme. Cell harvesting was classified as adequate when > 2 × 106 cells/kg were collected. RESULTS: Forty-seven patients (Hodgkin's lymphoma, 24; non-Hodgkin's lymphoma, 23) were included. Comparing groups of Hodgkin's lymphoma mobilized with chemotherapy (15 patients) and without chemotherapy (nine patients), one apheresis procedure was sufficient in 73 and 44% of patients, respectively (p = 0.04), the average of CD34 + cells/kg collected was 11 x 106 and 3 x 106, respectively (p = 0.017), and the collection was adequate in 100 and 55.6% of cases, respectively (p = 0.014). Comparing the groups of non-Hodgkin's lymphoma mobilized with chemotherapy (six patients) and without chemotherapy (17 patients), one apheresis procedure was sufficient in 33 and 65% of patients, respectively (p = 0.26), the average of CD34+ cells/kg was 3.56 x 106 and 3.41 x 106, respectively (p = 0.47), and collection was adequate in 66.6 and 59% of cases, respectively (p = 0.37). CONCLUSION: In Hodgkin's lymphoma patients, mobilization schemes with chemotherapy were more effective considering the number of cells collected, the number of apheresis required, and the percentage of successful cell collections. In non-Hodgkin's lymphoma patients, there were no significant differences between the two groups.


Assuntos
Antineoplásicos/farmacologia , Filgrastim/farmacologia , Fármacos Hematológicos/farmacologia , Mobilização de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Doença de Hodgkin/cirurgia , Linfoma não Hodgkin/cirurgia , Adolescente , Adulto , Criança , Ciclofosfamida/farmacologia , Etoposídeo/farmacologia , Feminino , Fator Estimulador de Colônias de Granulócitos , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Estudos Retrospectivos , Transplante Autólogo , Adulto Jovem
13.
Angew Chem Int Ed Engl ; 55(11): 3813-6, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26849473

RESUMO

Although tremendous progress has been made in the diagnosis of melanoma, the identification of different stages of malignancy in a reliable way remains challenging. Current strategies rely on optical monitoring of the concentration and spatial distribution of specific biomarkers. State-of-the-art optical methods can be affected by background-color interference and autofluorescence. We overcame these shortcomings by employing scanning electrochemical microscopy (SECM) to map the prognostic indicator tyrosinase (TyR) in non-metastatic and metastatic melanoma tissues by using soft-stylus microelectrodes. Electrochemical readout of the TyR distribution was enabled by adapting an immunochemical method. SECM can overcome the limitations of optical methods and opens unprecedented possibilities for improved diagnosis and understanding of the spatial distribution of TyR in different melanoma stages.


Assuntos
Melanoma/enzimologia , Microscopia Eletrônica de Varredura/métodos , Monofenol Mono-Oxigenase/metabolismo , Humanos , Melanoma/patologia , Metástase Neoplásica
14.
Anal Chem ; 87(2): 1026-33, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25555046

RESUMO

Polyacrylamide (PA) based hydrogels are used in several applications including polyacrylamide gel electrophoresis and sensing devices. Homogeneous and compact PA films can be prepared based on chemical or photopolymerization processes. However, the accurate and reproducible coating of substrates with nanohydrogel patterns is challenging due to the in situ polymerization and deposition requirements. Herein, we report an inkjet printing (IJP) concept with simultaneously performed UV photopolymerization of a specifically prepared acrylamide/N,N'-methylenebis(acrylamide) containing ink. A prepolymerization step of the hydrogel precursor molecules was implemented in the ink formulation protocol to adjust the viscosity of the ink and to enhance the rate of polymerization during printing. After the optimization of the printing parameters, a nanometer thin PA hydrogel coating with well distributed nanopores was achieved on top of a stand-alone carbon nanotubes (CNTs) pattern. Batches of fully inkjet printed PA/CNT modified electrodes were prepared that showed outstanding improvements for the electrochemical detection of antioxidants in complex matrices such as untreated orange juice and red wine samples thanks to the properties of the PA coating.

15.
Anal Chem ; 87(8): 4479-86, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25833001

RESUMO

To understand biological processes at the cellular level, a general approach is to alter the cells' environment and to study their chemical responses. Herein, we present the implementation of an electrochemical push-pull probe, which combines a microfluidic system with a microelectrode, as a tool for locally altering the microenvironment of few adherent living cells by working in two different perturbation modes, namely electrochemical (i.e., electrochemical generation of a chemical effector compound) and microfluidic (i.e., infusion of a chemical effector compound from the pushing microchannel, while simultaneously aspirating it through the pulling channel, thereby focusing the flow between the channels). The effect of several parameters such as flow rate, working distance, and probe inclination angle on the affected area of adherently growing cells was investigated both theoretically and experimentally. As a proof of concept, localized fluorescent labeling and pH changes were purposely introduced to validate the probe as a tool for studying adherent cancer cells through the control over the chemical composition of the extracellular space with high spatiotemporal resolution. A very good agreement between experimental and simulated results showed that the electrochemical perturbation mode enables to affect precisely only a few living cells localized in a high-density cell culture.


Assuntos
Microambiente Celular , Técnicas Eletroquímicas , Técnicas Analíticas Microfluídicas , Técnicas Eletroquímicas/instrumentação , Humanos , Concentração de Íons de Hidrogênio , Microeletrodos , Técnicas Analíticas Microfluídicas/instrumentação , Células Tumorais Cultivadas
16.
Chimia (Aarau) ; 69(5): 284-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26507347

RESUMO

Inkjet printing is a very powerful digital and mask-less microfabrication technique that has attracted the attention of several research groups working on electrochemical energy conversion concepts. In this short review, an overview is given about recent efforts to employ inkjet printing for the search of new electrocatalyst materials and for the preparation of catalyst layers for polymer electrolyte membrane fuel cell applications. Recent approaches of the Laboratory of Physical and Analytical Electrochemistry (LEPA) at the École Polytechnique Fédérale de Lausanne for the inkjet printing of catalyst layers and membrane electrode assemblies are presented and future energy research directions of LEPA based on inkjet printing in the new Energypolis campus in the Canton of Valais are summarized.

17.
Chimia (Aarau) ; 69(5): 290-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26507348

RESUMO

The Laboratoire d'Electrochimie Physique et Analytique (LEPA) has moved to the new Energypolis campus in Sion. This laboratory is involved in energy research in particular by studying charge transfer reactions at soft interfaces and developing interfacial redox electrocatalysis, by pioneering the concept of photo-ionic cells and by integrating redox flow batteries for the production of hydrogen at the pilot scale. Nonetheless, this laboratory has a long tradition in analytical chemistry with the development of microfabrication techniques such as laser photo-ablation, screen-printing and more recently inkjet printing for the design and fabrication of biosensors and immunosensors. As shown in the present review, the laboratory has recently pioneered new technologies for electrochemical and mass spectrometry imaging and for the screening of allergy in patients. The role of the laboratory in the Valais landscape will be to foster the collaboration with the HES to develop teaching and research in analytical chemistry as this field is a major source of employment for chemists.

18.
Anal Chem ; 86(1): 713-20, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24328212

RESUMO

Scanning electrochemical microscopy with soft microelectrode array probes has recently been used to enable reactivity imaging of extended areas and to compensate sample corrugation perpendicular to the scanning direction. Here, the use of a new type of microelectrode arrays is described in which each individual microelectrode can independently compensate corrugations of the sample surface. It consists of conventional Pt microelectrodes enclosed in an insulating glass sheath. The microelectrodes are individually fixed to a new holder system by magnetic forces. The concept was tested using a large 3D sample with heights up to 12 µm specially prepared by inkjet printing. The microelectrodes follow the topography in a constant working distance independently from each other while exerting low pressure on the surface.


Assuntos
Microscopia Eletroquímica de Varredura/instrumentação , Microscopia Eletroquímica de Varredura/métodos , Microeletrodos
19.
Foods ; 13(3)2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38338565

RESUMO

This research analyzed, optimized and modeled the inactivation kinetics of pathogenic bacteria (PB1: Escherichia coli O157:H7 and PB2: Listeria monocytogenes) and determined the microbiological safety of tomato juice processed by UV-LED irradiation and heat treatment. UV-LED processing conditions were optimized using response surface methodology (RSM) and were 90% power intensity, 21 min and 273-275 nm (251 mJ/cm2) with R2 > 0.96. Using the optimal conditions, levels of PB1 and PB2 resulted a log reduction of 2.89 and 2.74 CFU/mL, respectively. The Weibull model was efficient for estimating the log inactivation of PB1 and PB2 (CFU/mL). The kinetic parameter δ showed that 465.2 mJ/cm2 is needed to achieve a 90% log (CFU/mL) reduction in PB1 and 511.3 mJ/cm2 for PB2. With respect to the scale parameter p > 1, there is a descending concave curve. UV-LED-treated tomato juice had an 11.4% lower Listeria monocytogenes count than heat-treated juice on day 28 (4.0 ± 0.82 °C). Therefore, UV-LED technology could be used to inactivate Escherichia coli O157:H7 and Listeria monocytogenes, preserving tomato juice for microbiological safety, but studies are required to further improve the inactivation of these pathogens and analyze other fruit and vegetable juices.

20.
Food Res Int ; 186: 114337, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729718

RESUMO

A major concern for wineries is haze formation in white wines due to protein instability. Despite its prevalent use, the conventional bentonite method has shortcomings, including potential alteration of color and aroma, slow processing times, and notable wine wastage. Zirconium oxide (ZrO2) effectively removes proteins without affecting wine characteristics. However, producing cost-effective ZrO2 materials with efficient protein removal capabilities poses a significant challenge. This research aims to assess the viability of designing a porous material impregnated with zirconia to remove turbidity-causing proteins effectively. For this purpose, the support material alone (Al2O3) and the zirconia-impregnated support (ZrO2/Al2O3) were subjected to different calcination temperatures. It was observed that high-temperature treatments (750 °C) enhanced wine stability and protein adsorption capacity. The optimal adsorbent achieved a notable reduction in turbidity, decreasing the ΔNTU from 42 to 18, alongside a significant 44 % reduction in the total protein content, particularly affecting proteins in the molecular weight range of 10 to 70 kDa. This result is attributed to modifying the textural properties of ZrO2/Al2O3, characterized by the reduction of acidic sites, augmented pore diameters from 4.81 to 7.74 nm, and the emergence of zirconia clusters across the surface of the porous support. In summary, this study presents the first application of zirconia on the alumina support surface for protein stabilization in white wine. Combining ZrO2/Al2O3 and a high-temperature treatment emerges as a promising, cost-efficient, and environmentally sustainable strategy for protein removal in white wine.


Assuntos
Óxido de Alumínio , Vinho , Zircônio , Vinho/análise , Zircônio/química , Óxido de Alumínio/química , Adsorção , Estabilidade Proteica , Temperatura Alta , Manipulação de Alimentos/métodos
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