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1.
Plant Foods Hum Nutr ; 79(2): 503-510, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38607507

RESUMO

This study delves into the transformative effects of atmospheric cold plasma (CP) treatment on little millet flour (LMF), specifically exploring alterations in bioactive compounds, antinutritional factors, and functional properties. Foaming and emulsification properties experienced noteworthy enhancements with plasma treatment, manifesting in significant increases in foaming capacity (up to 51.47 ± 0.49%), foaming stability, emulsification ability, and emulsion stability (up to 47.02 ± 0.35%). The treatment also positively influenced water absorption index and swelling power. Antinutritional factors, including tannins and saponins, exhibited substantial reductions following plasma treatment. Saponin content, for instance, decreased by an impressive 58% after exposure to 20 kV for 20 min. Conversely, bioactive compounds such as phenolic content and antioxidant activity saw significant increases. Total phenolic content (TPC) rose from 527.54 ± 8.94 to 575.82 ± 3.58 mg GAE/100 g, accompanied by a remarkable 59% boost in antioxidant activity. Interestingly, plasma treatment did not exhibit a discernible effect on pasting properties. These findings collectively underscore the potential of atmospheric CP treatment as a novel and effective method for enhancing the functional and nutritional attributes of LMF, thereby opening new avenues for its application in food science and technology.


Assuntos
Antioxidantes , Farinha , Manipulação de Alimentos , Fenóis , Gases em Plasma , Saponinas , Taninos , Farinha/análise , Antioxidantes/análise , Fenóis/análise , Saponinas/análise , Manipulação de Alimentos/métodos , Taninos/análise , Valor Nutritivo , Milhetes/química
2.
Crit Rev Food Sci Nutr ; 63(6): 719-752, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34309440

RESUMO

Fruits and vegetables are the most important commodities of trade value among horticultural produce. They are utilized as raw or processed, owing to the presence of health-promoting components. Significant quantities of waste are produced during fruits and vegetables processing that are majorly accounted by waste peels (∼90-92%). These wastes, however, are usually exceptionally abundant in bioactive molecules. Retrieving these valuable compounds is a core objective for the valorization of waste peel, besides making them a prevailing source of beneficial additives in food and pharmaceutical industry. The current review is focused on extraction of bioactive compounds derived from fruit and vegetable waste peels and highlights the supreme attractive conventional and non-conventional extraction techniques, such as microwave-assisted, ultrasound assisted, pulsed electric fields, pulsed ohmic heating, pressurized liquid extraction, supercritical fluid extraction, pressurized hot water, high hydrostatic pressure, dielectric barrier discharge plasma extraction, enzyme-assisted extraction and the application of "green" solvents say as well as their synergistic effects that have been applied to recover bioactive from waste peels. Superior yields achieved with non-conventional technologies were identified to be of chief interest, considering direct positive economic consequences. This review also emphasizes leveraging efficient, modern extraction technologies for valorizing abundantly available low-cost waste peel, to achieve economical substitutes, whilst safeguarding the environment and building a circular economy. It is supposed that the findings discussed though this review might be a valuable tool for fruit and vegetable processing industry to imply an economical and effectual sustainable extraction methods, converting waste peel by-product to a high added value functional product.


Assuntos
Frutas , Verduras , Frutas/química , Antioxidantes/análise , Solventes
3.
Food Res Int ; 141: 110138, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33642005

RESUMO

Pesticide and agrochemical residues in food and water are among hazardous chemicals that are associated with adverse health effects. Consequently, technologies for pesticide abatement in food and water remain in focus. Cold plasma is an emerging decontamination technology, that is being increasingly explored for the abatement of agrochemical and pesticide residue in food and water. In some cases, rapid and complete degradation of pesticide residues has come to light. Such promising results encourage exploring scale-up and commercialization. To achieve this, unraveling mechanisms involved in plasma decontamination and the nature of degradation products is needed. The present review identifies the mechanisms involved in plasma- assisted removal of pesticide residues from food and water, draws parallels with mechanism of ozone and ultraviolet technologies, investigates the chemistry of the intermediates and degradates, and identifies some future research needs. The review recognizes that mechanisms involved in plasma processes have overlapping similarities to those identified for ozone and ultraviolet light, involving oxidation by hydroxyl radical and photo-oxidation. The toxicity of intermediates and degradates in plasma processing have not received much attention. The safety aspects of end products form plasma led degradation of pesticides should be considered for practical exploitation. Identification of intermediates and degradation products, recognition of most potent plasma species, understanding the influence of co-existing entities, the energy efficiency of plasma reactors, and the process economics deserve research focus.


Assuntos
Ozônio , Resíduos de Praguicidas , Gases em Plasma , Agroquímicos , Resíduos de Praguicidas/análise , Tecnologia , Água
4.
Crit Rev Food Sci Nutr ; 61(4): 666-689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32208859

RESUMO

Atmospheric cold plasma (ACP) is an emerging technology in the food industry with a huge antimicrobial potential to improve safety and extend the shelf life of food products. Dielectric barrier discharge (DBD) is a popular approach for generating ACP. Thanks to the numerous advantages of DBD ACP, it is proving to be successful in a number of applications, including microbial decontamination of foods. The antimicrobial efficacy of DBD ACP is influenced by multiple factors. This review presents an overview of ACP sources, with an emphasis on DBD, and an analysis of their antimicrobial efficacy in foods in open atmosphere and in-package modes. Specifically, the influence of process, product, and microbiological factors influencing the antimicrobial efficacy of DBD ACP are critically reviewed. DBD ACP is a promising technology that can improve food safety with minimal impact on food quality under optimal conditions. Once the issues pertinent to scale-up of plasma sources are appropriately addressed, the DBD ACP technology will find wider adaptation in food industry.


Assuntos
Anti-Infecciosos , Gases em Plasma , Manipulação de Alimentos , Qualidade dos Alimentos , Inocuidade dos Alimentos
5.
Food Chem ; 344: 128573, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33199117

RESUMO

The rising awareness about the adverse health effects of high sugar consumption has led to regulatory amendments for triggering sugar reduction in food products. Sugar reduction in yogurt is a challenging endeavor due to the changes in taste, flavor, texture, maintenance of food functionality, shelf-life, cost and consumer acceptability. A review of the scientific literature, patents, and web articles revealed several approaches being explored by the dairy industry to reduce the sugar addition. A careful assessment of these strategies and their critical analysis is presented in this review. The strategies for sugar reduction involve multifaceted approaches including the use of alternative low-calorie sweeteners, honey, fruit preparations, novel cultures, lactase addition, inulin fiber addition, and flavor interventions. Much of the work so far has focused on development of low-calorie alternative sweeteners, and novel sweeteners-based solutions are evolving. The use of food structuring approaches remains to be explored for sugar reduction in yogurt.


Assuntos
Edulcorantes/análise , Iogurte/análise , Produtos Biológicos/análise , Humanos , Paladar
6.
J Food Sci ; 85(4): 1203-1212, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32118300

RESUMO

Listeria monocytogenes is often responsible for postprocessing contamination of ready-to-eat (RTE) products including cooked ham. As an emerging technology, atmospheric cold plasma (ACP) has the potential to inactivate L. monocytogenes in packaged RTE meats. The objectives of this study were to evaluate the effect of treatment time, modified atmosphere gas compositions (MAP), ham formulation, and post-treatment storage (1 and 7 days at 4 °C) on the reduction of a five-strain cocktail of L. monocytogenes and quality changes in ham subjected to in-package ACP treatment. Initial average cells population on ham surfaces were 8 log CFU/cm2 . The ACP treatment time and gas composition significantly (P < 0.05) influenced the inactivation of L. monocytogenes, irrespective of ham formulations. When MAP1 (20% O2 + 40% CO2 + 40% N2 ) was used, there was a significantly higher log reduction (>2 log reduction) in L. monocytogenes on ham in comparison to MAP2 (50% CO2 + 50% N2 ) and MAP3 (100% CO2 ), irrespective of ham formulation. Addition of preservatives (that is, 0.1% sodium diacetate and 1.4% sodium lactate) or bacteriocins (that is, 0.05% of a partially purified culture ferment from Carnobacterium maltaromaticum UAL 307) did not significantly reduce cell counts of L. monocytogenes after ACP treatment. Regardless of type of ham, storage of 24 hr after ACP treatment significantly reduced cells counts of L. monocytogenes to approximately 4 log CFU/cm2 . Following 7 days of storage after ACP treatment, L. monocytogenes counts were below the detection limit (>6 log reduction) when samples were stored in MAP1. However, there were significant changes in lipid oxidation and color after post-treatment storage. In conclusion, the antimicrobial efficacy of ACP is strongly influenced by gas composition inside the package and post-treatment storage. PRACTICAL APPLICATION: Surface contamination of RTE ham with L. monocytogenes may occur during processing steps such as slicing and packaging. In-package ACP is an emerging nonthermal technology, which can be used as a postpackaging decontamination step in industrial settings. This study demonstrated the influence of in-package gas composition, treatment time, post-treatment storage, and ham formulation on L. monocytogenes inactivation efficacy of ACP. Results of present study will be helpful to optimize in-package ACP treatment and storage conditions to reduce L. monocytogenes, while maintaining the quality of ham.


Assuntos
Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Produtos da Carne/microbiologia , Gases em Plasma/farmacologia , Animais , Bacteriocinas/farmacologia , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Embalagem de Alimentos/instrumentação , Conservação de Alimentos/instrumentação , Conservantes de Alimentos/farmacologia , Armazenamento de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Produtos da Carne/análise , Lactato de Sódio/farmacologia , Suínos
7.
S Afr Med J ; 111(1): 61-67, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33404008

RESUMO

BACKGROUND: Optimal drug levels and minimal toxicity are critical factors in improving treatment outcomes for patients' prescribed new and repurposed medicine for drug-resistant (DR) tuberculosis (TB). The optimal dose of clofazimine (CFZ), a repurposed medicine for DR-TB, that is safe and effective in the South African (SA) population is unknown. OBJECTIVES: To report on dose-related final treatment outcomes in patients receiving CFZ plus a background regimen for DR-TB. METHODS: In a retrospective review of patient folders from 2012 to 2014, treatment outcomes documented for patients receiving high- (≥200 mg) and low-dose (100 mg) CFZ in a centralised DR-TB hospital in KwaZulu-Natal Province, SA, were investigated for an association between dose-weight interactions and outcomes. RESULTS: A total of 600 patients were included, of whom 169 (28.2%) received 100 mg. Of these, 87 (51.5%) weighed <50 kg and 82 (48.5%) ≥50 kg. Four hundred and thirty-one (71.8%) received ≥200 mg, of whom 41 (9.5%) were <50 kg and 390 (90.5%) ≥50 kg. Overall 77.2% were HIV-positive, with 93.95% on antiretroviral medicine. The majority of patients presented with extremely drug-resistant TB (55.3%). Forty-seven and a half percent of patients received a standardised background regimen, and 52.5% received an individualised regimen containing a new or repurposed medicine including CFZ. On multivariate analysis, adjusting for age, gender, HIV status and concomitant antiretrovirals, previous TB history, type of TB and background regimen, patients ≥50 kg prescribed 100 mg CFZ were 60% less likely to have a successful outcome (adjusted odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2 - 0.8; p=0.009) compared with patients <50 kg receiving 100 mg CFZ. Patients <50 kg who received ≥200 mg were 40% less likely to have a successful treatment outcome (adjusted OR 0.6, p=0.3), and were found to have a higher risk of adverse events than patients <50 kg receiving 100 mg CFZ (82.9% v. 65.5%). CONCLUSIONS: Dose-weight interaction plays a role in the odds of a successful outcome. There is an association between dose-weight interactions, outcomes and adverse events. Weight-based dosing in patients <50 kg and ≥50 kg must be considered to achieve optimal treatment outcomes and reduce adverse events. Active drug safety monitoring must be implemented as a package of care for patients receiving CFZ as part of a DR-TB treatment regimen.


Assuntos
Antituberculosos/administração & dosagem , Clofazimina/administração & dosagem , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/efeitos adversos , Peso Corporal , Clofazimina/efeitos adversos , Estudos de Coortes , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , África do Sul , Resultado do Tratamento , Adulto Jovem
8.
Meat Sci ; 159: 107942, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31522105

RESUMO

Atmospheric cold plasma (ACP) is a promising non-thermal technology for controlling food spoilage. In this study, ACP treatment at 100 kV for 1, 3 and 5 min was applied to chicken breast samples. Approximately 2 log CFU/g reduction in natural microflora of chicken was achieved within 5 min of treatment and 24 h of storage. The observed reduction was attributed to the reactive oxygen and nitrogen species in cold plasma. For shelf-life study, control and ACP treated samples (100 kV for 5 min) were analysed for the population of mesophiles, psychrotrophs and Enterobacteriaceae as well as sample colour and pH over a storage period of 24 days. On day 24, the population of mesophiles, psychrotrophs and Enterobacteriaceae in treated chicken was respectively 1.5, 1.4 and 0.5 log lower than the control. These results suggest that in-package ACP is an effective technology to extend the shelf-life of poultry products.


Assuntos
Microbiologia de Alimentos , Embalagem de Alimentos , Carne/microbiologia , Gases em Plasma , Animais , Bactérias/efeitos da radiação , Galinhas/microbiologia , Carne/análise , Fatores de Tempo
9.
S Afr Med J ; 110(1): 32-37, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31865940

RESUMO

BACKGROUND: Optimal drug levels and minimal toxicity are critical factors in improving treatment outcomes for patients prescribed new and repurposed medicine for drug-resistant (DR) tuberculosis (TB). The optimal dose and dose-related safety of clofazimine (CFZ), a repurposed medicine for DR TB, in the South African (SA) population are unknown. OBJECTIVES: To report on dose-related adverse events in patients receiving CFZ plus a background regimen for DR TB. METHODS: In a retrospective review of patient folders from 2012 to 2014, adverse events documented for patients receiving high- (≥200 mg) and low-dose (100 mg) CFZ in a centralised DR TB hospital in KwaZulu-Natal Province, SA, were investigated for an association between dose-weight interactions and adverse events. RESULTS: Of 600 patients included, 78.7% (n=472) weighed ≥50 kg. Of these, 17.4% (n=82) received 100 mg CFZ and 82.6% (n=390) received >200 mg. Of 128 patients (21.3%) who weighed <50 kg, 68.0% (n=87) received 100 mg CFZ and 32.0% (n=41) received ≥200 mg. Of 463 patients (77.2%) who were HIV-positive, 94.0% were on antiretrovirals. There was no difference between the dose-weight cohorts in the background regimen given in addition to high- or low-dose CFZ. The frequency and types of adverse events observed were similar to the published literature. When analysed per dose-weight cohort, patients weighing <50 kg and receiving high-dose CFZ (≥200 mg) had a 2.6 times higher risk of any adverse event (adjusted odds ratio (aOR) 2.57; 95% confidence interval (CI) 1.02 - 6.05; p=0.05: reference category <50 kg and 100 mg). Patients weighing <50 kg and receiving high-dose CFZ had a 3.3 times higher risk of gastrointestinal adverse events than patients weighing <50 kg and receiving 100 mg CFZ (aOR 3.30; 95% CI 1.51 - 7.19; p=0.003). A high risk of chest pain was observed in patients receiving high- and low-dose CFZ, irrespective of weight. Patients weighing <50 kg receiving high-dose CFZ had a slightly higher risk of adverse events related to the skin (aOR 1.2; 95% CI 0.55 - 2.62; p=0.7) There were no documented reports of the CFZ dose being reduced or the drug being stopped due to adverse events in the sample population. CONCLUSIONS: There is an association between dose-weight interaction and adverse events. The odds of any adverse event occurring were higher when low-weight patients (<50 kg) received high-dose CFZ (≥200 mg). Gastrointestinal and skin-related adverse events were more common when high-dose CFZ was used in patients weighing <50 kg. Chest pain was reported in patients receiving high- and low-dose CFZ, irrespective of weight, and may be a symptom of cardiac toxicity. Plasma concentrations of CFZ may be affected by drug-drug interactions, so active drug safety monitoring including electrocardiograms is recommended routinely when CFZ is part of the regimen.


Assuntos
Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Clofazimina/administração & dosagem , Clofazimina/efeitos adversos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/uso terapêutico , Antituberculosos/uso terapêutico , Clofazimina/uso terapêutico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , África do Sul , Adulto Jovem
10.
Food Chem ; 284: 303-311, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744862

RESUMO

This study examined high voltage atmospheric cold plasma (HVACP) technology as a non-thermal intervention for inactivating Salmonella enterica serovar Typhimurium LT2 (ST2) in tender coconut water (TCW). Treatment with HVACP in air at 90 kV for 120 s inactivated 1.30 log10 of ST2. Development of a TCW stimulant suggested an interfering role of magnesium and phosphate salts with HVACP inactivation. Generation of reactive gas species, viz. ozone and hydrogen peroxides were found to be responsible for microbial inactivation. The addition of 400 ppm citric acid to the TCW effectively reduced ST2 by 5 log10 during HVACP treatment. Under these conditions, higher cellular leakage and morphological damage were observed in ST2. Minimal physico-chemical changes in TCW were observed with HVACP treatment, except for an 84.35% ascorbic acid loss (added externally). These results demonstrate a potential pathway for developing highly effective cold plasma treatments to preserve fruit and vegetable juices.


Assuntos
Cocos/química , Sucos de Frutas e Vegetais/análise , Gases em Plasma/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Ácido Ascórbico/farmacologia , Ácido Cítrico/farmacologia , Microbiologia de Alimentos , Viabilidade Microbiana/efeitos dos fármacos , Dióxido de Nitrogênio/química , Dióxido de Nitrogênio/farmacologia , Ozônio/química , Ozônio/farmacologia
11.
Compr Rev Food Sci Food Saf ; 18(1): 106-120, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33337013

RESUMO

Cold plasma treatment is a promising intervention in food processing to boost product safety and extend the shelf-life. The activated chemical species of cold plasma can act rapidly against micro-organisms at ambient temperatures without leaving any known chemical residues. This review presents an overview of the action of cold plasma against molds and mycotoxins, the underlying mechanisms, and applications for ensuring food safety and quality. The cold plasma species act on multiple sites of a fungal cell resulting in loss of function and structure, and ultimately cell death. Likewise, the species cause chemical breakdown of mycotoxins through various pathways resulting in degradation products that are known to be less toxic. We argue that the preliminary reports from cold plasma research point at good potential of plasma for shelf-life extension and quality retention of foods. Some of the notable food sectors which could benefit from antimycotic and antimycotoxin efficacy of cold plasma include, the fresh produce, food grains, nuts, spices, herbs, dried meat and fish industries.

12.
Anal Chem ; 90(18): 11070-11077, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30091364

RESUMO

A simple, safe, and sensitive method for direct multielemental trace determinations in plutonium samples using total reflection X-ray fluorescence (TXRF) spectrometry has been developed. A very small volume (2 µL) of the sample solutions was deposited on TXRF supports after separation of the plutonium matrix from these solutions. Since the amount of the plutonium deposited on the supports was in the ng level only fixed on the supports and the specimen spots were not disturbed during the sample preparation, the samples could be analyzed directly without putting the instrument in a glovebox. This approach avoided a cumbersome operation of the instrument in a glovebox, which is normally utilized for Pu-based samples using other techniques. Similarly, the requirement of small amounts of the samples minimized the radiation dose to the operator as well as a cumbersome problem of management of radioactive analytical waste of plutonium samples. The samples were analyzed using the TXRF spectra of the specimens, concentration of the internal standard Se or Ga and predetermined sensitivity values. The elemental detection limits for the elements K-Sr varied from 1.06 to 0.09 ng. The elements K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, Tl, and Pb were analyzed at µg/mL level. The analytical results of TXRF determinations showed average relative standard deviation (RSD) value of 4.5% (1σ, n = 3) and the TXRF determined results deviated from the expected values by 5.9% on average for samples prepared by adding multielements in plutonium solutions. Two real plutonium samples were also analyzed in similar manner. For the real plutonium sample solution the average RSD values of TXRF determinations were 10.6% (1σ, n = 3) for the elemental concentrations in the range of 0.2 to 61 µg/mL. These values are comparable with conventional trace element analytical techniques with added advantages mentioned above.

13.
Vaccine ; 36(24): 3513-3521, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29739718

RESUMO

Staphylococcus aureus causes a chronic, contagious disease of the udder, or mastitis, in dairy cows. This infection is often refractory to antibiotic treatment, and has a significant economic impact on milk production worldwide. An effective vaccine to prevent S. aureus mastitis would improve animal health, reduce antibiotic dependence and inform human vaccine approaches. The iron-regulated surface determinant A (IsdA) and clumping factor A (ClfA) are conserved S. aureus extracellular-matrix adhesins and target vaccine antigens. Here we report the results of two bovine immunogenicity trials using purified IsdA and ClfA-cholera toxin A2/B chimeras (IsdA-CTA2/B and ClfA-CTA2/B). Cows were intranasally inoculated with IsdA-CTA2/B + ClfA-CTA2/B at dry off and followed for 70 days. Trial 1 utilized three groups with one or two booster doses at a total concentration of 600 or 900 µg. Trial 2 utilized two groups with one booster at a total concentration of 1200 µg. Humoral immune responses in serum and milk were examined by ELISA. Responses in serum were significant between groups and provide evidence of antigen-specific IgG induction after vaccination in both trials. Cellular proliferation was detected by flow cytometry using antigen-stimulated PBMCs from day 60 of Trial 2 and revealed an increase in CD4+ T cells from vaccinated cows. IsdA and ClfA stimulation induced IL-4 expression, but not IFN-γ or IL-17, in PBMCs from day 60 as determined by cytokine expression analysis. Opsonophagocytosis of S. aureus confirmed the functional in vitro activity of anti-IsdA antibodies from Trial 2 serum and milk. The vaccine was well tolerated and safe, and results support the potential of mucosally-delivered CTA2/B chimeras to protect cows from mastitis caused by S. aureus.


Assuntos
Anticorpos Antibacterianos/biossíntese , Mastite Bovina/prevenção & controle , Proteínas Recombinantes de Fusão/imunologia , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/biossíntese , Administração Intranasal , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/microbiologia , Bovinos , Proliferação de Células/efeitos dos fármacos , Toxina da Cólera/administração & dosagem , Toxina da Cólera/genética , Toxina da Cólera/imunologia , Coagulase/administração & dosagem , Coagulase/genética , Coagulase/imunologia , Feminino , Expressão Gênica , Imunidade Humoral/efeitos dos fármacos , Imunização Secundária/métodos , Imunogenicidade da Vacina , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Interleucina-4/biossíntese , Interleucina-4/metabolismo , Glândulas Mamárias Animais/imunologia , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia , Leite/química , Leite/imunologia , Leite/microbiologia , Isoformas de Proteínas/administração & dosagem , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Vacinas Antiestafilocócicas/administração & dosagem , Vacinas Antiestafilocócicas/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/imunologia , Staphylococcus aureus/patogenicidade
14.
J Dairy Sci ; 101(7): 6296-6309, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29729920

RESUMO

Staphylococcus aureus is an opportunistic pathogen affecting both human and animal species. An effective vaccine to prevent S. aureus bovine disease and transmission would have positive effects on animal well-being, food production, and human health. The objective of this study was to identify multiple antigens that are immunoreactive during udder colonization and disease for exploration as vaccine antigens to prevent bovine mastitis. Staphylococcus aureus produces several cell wall-anchored and surface-associated virulence factors that play key roles in the pathogenesis of mastitis. Many of these proteins are conserved between different strains of S. aureus and represent promising vaccine candidates. We used an immunoproteomics approach to identify antigenic proteins from the surface of S. aureus. The expression of cell wall and surface proteins from S. aureus was induced under low iron conditions, followed by trypsin extraction and separation by 2-dimensional electrophoresis. The separated proteins were blotted with antibodies from mastitic bovine milk and identified by liquid chromatography-mass spectrometry. Thirty-eight unique proteins were identified, of which 8 were predicted to be surface exposed and involved in S. aureus virulence. Two surface proteins, iron-regulated surface determinant protein C (IsdC) and ESAT-6 secretion system extracellular protein (EsxA), were cloned, expressed, and purified from Escherichia coli for confirmation of immune reactivity by ELISA. A PCR of 37 bovine S. aureus isolates indicated that the presence of esxA and isdC is conserved, and amino acid alignments revealed that IsdC and EsxA sequences are highly conserved. The immunoproteomics technique used in this study generated reproducible results and identified surface exposed and reactive antigens for further characterization.


Assuntos
Antígenos de Bactérias/imunologia , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/imunologia , Vacinação/veterinária , Animais , Bovinos , Feminino , Mastite Bovina/prevenção & controle , Leite , Staphylococcus aureus/patogenicidade
15.
J Food Sci Technol ; 55(3): 985-991, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29487440

RESUMO

The baby foods industry is currently seeking technologies to pasteurize products without formation of processing contaminants such as furan. This work demonstrates the applicability of high hydrostatic pressure (HHP) as a non-thermal decontamination intervention for fruit purée based baby foods. HHP processing was evaluated at 200, 300, and 400 MPa pressures, for 5, 10 and 15 min of treatment times at 25, 35 and 45 °C. HHP application at 400 MPa, 45 °C for 15 min ensured complete inactivation (about 6 log10) of total mesophilic aerophiles, as well as yeasts and molds. No furan was detected in HHP processed products. Thus, the key advantage of HHP over thermal processing is the ability to achieve commercially acceptable microbiological inactivation while avoiding the formation of processing contaminants such as furan.

16.
Crit Rev Food Sci Nutr ; 58(11): 1832-1863, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28362174

RESUMO

Interest in the development and adoption of nonthermal technologies is burgeoning within the food and bioprocess industry, the associated research community, and among the consumers. This is evident from not only the success of some innovative nonthermal technologies at industrial scale, but also from the increasing number of publications dealing with these topics, a growing demand for foods processed by nonthermal technologies and use of natural ingredients. A notable feature of the nonthermal technologies such as cold plasma, electrohydrodynamic processing, pulsed electric fields, and ultrasound is the involvement of external fields, either electric or sound. Therefore, it merits to study the fundamentals of these technologies and the associated phenomenon with a unified approach. In this review, we revisit the fundamental physical and chemical phenomena governing the selected technologies, highlight similarities, and contrasts, describe few successful applications, and finally, identify the gaps in research.


Assuntos
Eletroquímica , Tecnologia de Alimentos , Termodinâmica , Fenômenos Químicos , Manipulação de Alimentos , Microbiologia de Alimentos , Qualidade dos Alimentos , Armazenamento de Alimentos , Pressão Hidrostática , Modelos Teóricos , Gases em Plasma , Espécies Reativas de Oxigênio/metabolismo , Ondas Ultrassônicas
17.
Food Res Int ; 101: 17-23, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28941680

RESUMO

The inactivation of pathogenic and spoilage bacteria as well as the formation of food processing contaminants (e.g. acrylamide, furan, etc.) in infant foods is of utmost importance for industry, consumers as well as regulatory bodies. In this study, the potential of high hydrostatic pressure (HHP) for microorganism inactivation including total mesophilic aerobic bacteria (TMA) and total yeasts and molds (TYM) at equivalent processing conditions, as well as its effects on furan formation in vegetable-based infant food was evaluated. The process parameters evaluated were combinations of pressures (200, 300, and 400MPa), temperatures (25, 35, and 45°C), and treatment times (5, 10, and 15min). Pressure, time and temperature had a significant influence on both TMA and TYM inactivation of vegetable-based infant foods, observing a significant reduction in both microbial populations when all the factors were increased, although the extent of reduction was clearly influenced by the type of microorganism. A synergism between pressure, time and temperature was observed for the reduction of both TMA and TYM populations and it was found that HHP at 400MPa resulted in a complete inactivation of TMA as well as TYM after 15min of treatment at 45°C. The furan content in all HHP treated samples was found to be below the limit of detection. Thus, HHP treatment could be considered as a potential alternative to thermal processing of vegetable-based infant foods.


Assuntos
Bactérias/efeitos dos fármacos , Conservação de Alimentos/métodos , Furanos/farmacologia , Alimentos Infantis , Viabilidade Microbiana/efeitos dos fármacos , Verduras/química , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Fungos , Pressão Hidrostática , Pressão , Temperatura , Leveduras
18.
Food Res Int ; 97: 318-339, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28578057

RESUMO

Over a course of centuries, various food processing technologies have been explored and implemented to provide safe, fresher-tasting and nutritive food products. Among these technologies, application of emerging food processes (e.g., cold plasma, pressurized fluids, pulsed electric fields, ohmic heating, radiofrequency electric fields, ultrasonics and megasonics, high hydrostatic pressure, high pressure homogenization, hyperbaric storage, and negative pressure cavitation extraction) have attracted much attention in the past decades. This is because, compared to their conventional counterparts, novel food processes allow a significant reduction in the overall processing times with savings in energy consumption, while ensuring food safety, and ample benefits for the industry. Noteworthily, industry and university teams have made extensive efforts for the development of novel technologies, with sound scientific knowledge of their effects on different food materials. The main objective of this review is to provide a historical account of the extensive efforts and inventions in the field of emerging food processing technologies since their inception to present day.


Assuntos
Manipulação de Alimentos , Desenho de Equipamento , Manipulação de Alimentos/história , Manipulação de Alimentos/instrumentação , Manipulação de Alimentos/métodos , História do Século XXI , Pressão , Temperatura , Ultrassom
19.
Anal Chem ; 89(1): 871-876, 2017 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-27936602

RESUMO

Total reflection X-ray fluorescence (TXRF)-based X-ray absorption near-edge spectroscopy has been used to determine the oxidation state of uranium in mixed-valent U3O8 and U3O7 uranium oxides. The TXRF spectra of the compounds were measured using variable X-ray energies in the vicinity of the U L3 edge in the TXRF excitation mode at the microfocus beamline of the Indus-2 synchrotron facility. The TXRF-based X-ray absorption near-edge spectroscopy (TXRF-XANES) spectra were deduced from the emission spectra measured using the energies below and above the U L3 edge in the XANES region. The data processing using TXRF-XANES spectra of U(IV), U(V), and U(VI) standard compounds revealed that U present in U3O8 is a mixture of U(V) and U(VI), whereas U in U3O7 is mixture of U(IV) and U(VI). The results obtained in this study are similar to that reported in literature using the U M edge. The present study has demonstrated the possibility of application of TXRF for the oxidation state determination and elemental speciation of radioactive substances in a nondestructive manner with very small amount of sample requirement.

20.
Dalton Trans ; 45(18): 7650-64, 2016 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27052597

RESUMO

La doped Bi2UO6 solid solutions of the general formula Bi2-2xLa2xUO6 (x = 0-0.05) were prepared by the solid state reaction of Bi2O3, La(OH)3 and U3O8 in a stoichiometric ratio. These solid solutions were characterized by X-ray diffraction, Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Spectroscopy (XANES) studies. It was found that La goes to the Bi sites of the Bi2UO6 lattice during the formation of these solid solutions. For further confirmation, a photoluminescence (PL) study on an iso-structural Bi1.96Eu0.04UO6 was performed, and this supports the above observation. The solid solutions were also probed by EPR studies. The PL and EPR studies suggest that there are doping induced oxygen vacancies in these solid solutions.

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