Tecnologias inovadoras para o processamento sequencial combinado visando a melhoria de pasteurização de ovo-produtos

A new approach combining non-thermal pre-treatments before a less intense thermal pasteurization (TP) was evaluated as an alternative to commercial egg products TP. Thus, this work aimed to evaluate the performance of pressure (50 – 400 MPa/5 – 20 min) and ultrasound (US, 50% amplitude/1 – 3 min) pre-treatments (singly and/or combined) before a shorter TP on egg products, versus commercial TP, to assess the effect on microorganisms’ inactivation (Salmonella Senftenberg 775/W and Listeria innocua) and egg quality properties. Initially, in egg white (EW), using moderate pressure (MP) followed by a shorter TP (MP-TP) allowed to reduce S. Senftenberg 775/W and Listeria innocua population up to 4.4 log₁₀ cycles, while a higher inactivation was obtained with commercial TP. Overall, the combined treatment resulted in better retention of EW properties than commercial TP. However, the meringues prepared with treated and non-treated EW showed similar global acceptability. On the other hand, for egg yolk (EY), the same inactivation level was attained with MP-TP and commercial TP, yet, in general, the combined treatment allowed obtaining EY with better quality properties. However, MP-TP treatment caused more pronounced changes in EY volatile profile, but the “Doce de ovos” prepared with this sample had a higher sensory acceptability. In liquid whole egg (LWE), the combined treatment and commercial TP achieved a similar lethal effect, with the MP-TP maintaining and/or improving some properties of pasteurized LWE. Still, the egg tart prepared based on the treated and non-treated LWEs obtained similar sensory acceptability. Posteriorly, the combination of MP and US pre-treatments with a subsequent shorter TP (MP-US-TP), applied in LWE, reached a safety level against S. Senftenberg 775/W similar to that of commercial TP. Although, the latter retained better the quality properties of raw LWE. Therefore, the results indicated that the reduction of TP intensity when applied in combination with a MP pre-treatment could be an alternative to commercial egg products TP, offering a similar safety level against S. Senftenberg 775/W, and also to maintain and/or improve egg quality properties.Uma nova abordagem combinando pré-tratamentos não térmicos seguidos de uma pasteurização térmica (PT) menos intensa foi avaliada como uma alternativa à PT comercial de ovo-produtos. Assim, este trabalho teve como objetivo avaliar o efeito de pré-tratamentos de pressão (50 – 400 MPa/5 – 20 min) e ultrassom (US, 50% amplitude/1 – 3 min) (isoladamente e/ou combinados) antes de uma PT mais curta, na inativação de microrganismos (Salmonella Senftenberg 775/W e Listeria innocua) e nas propriedades de qualidade dos ovo-produtos, versus PT comercial. Em clara de ovo (CO), a utilização de pressão moderada (PM) seguida de uma PT mais curta (PM-PT) inativou cerca de 4,4 ciclos log₁₀ de S. Senftenberg 775/W e L. innocua, mas a PT comercial causou uma maior inativação. No geral, o tratamento combinado reteve melhor as propriedades de qualidade da CO do que a PT comercial. Porém, os merengues preparados com as amostras tratadas e não tratadas obtiveram a mesma aceitabilidade. Para a gema de ovo (GO), obteve-se o mesmo nível de inativação utilizando PM-PT e TP comercial, mas em geral, o tratamento combinado permitiu obter uma GO com melhores propriedades de qualidade. No entanto, o PM-PT causou alterações mais pronunciadas no perfil volátil da GO, mas o doce de ovos preparado com esta amostra apresentou maior aceitabilidade sensorial. Em ovo inteiro líquido (OIL), o tratamento combinado e a PT comercial alcançaram um efeito letal equivalente, todavia o tratamento de PM-PT manteve ou melhorou algumas das propriedades de qualidade do OIL pasteurizado. Além disso, as tartes de ovo preparadas com as amostras tratadas e não tratadas obtiveram aceitabilidade sensorial semelhante. Posteriormente, a combinação de pré-tratamentos de PM e US com uma PT mais curta (PM-US-PT), aplicada em OIL, alcançou o mesmo nível de inativação que a PT comercial. Contudo, a PT comercial reteve melhor as propriedades de qualidade do OIL do que o tratamento de PM-US-PT. Assim, os resultados indicaram que a redução da intensidade da PT quando aplicada em combinação com um pré-tratamento de PM pode ser uma alternativa à PT comercial, alcançando um nível de segurança semelhante, mas mantendo e/ou melhorando as propriedades de qualidade dos ovo-produtos.Programa Doutoral em Ciência e Tecnologia Alimentar e Nutriçã

Efeito combinado da pressão e da temperatura na produção de Kefir

Mestrado em BioquímicaO kefir e uma bebida lactea levemente gaseificada, com baixo teor alcoolico e de consistencia cremosa. Esta bebida e produzida a partir de graos de kefir ou culturas starter que podem consistir numa mistura de bacterias acido-lacticas, bacterias acido-aceticas e leveduras, caracterizando-se por apresentar um pH entre 4,2 - 4,6. Este trabalho teve como objetivo estudar o efeito combinado da pressao e da temperatura no processo de fermentacao de kefir. Para isso, a fermentacao foi realizada sob diferentes combinacoes de pressao e temperatura (7, 15, 30 e 50 MPa a . 17 oC e a 15 e 50 MPa a 25 e 32 oC), sendo monitorizada a variacao de pH, a acidez titulavel, a concentracao de acucares redutores e a concentracao de acido lactico. A temperatura ambiente (. 17 oC) os resultados revelaram que o aumento da pressao reduziu a velocidade fermentativa, uma vez que se verificou uma variacao mais lenta do pH, da acidez titulavel e da concentracao de acucares redutores ao longo da fermentacao, sendo que a 50 MPa quase nao ocorreu fermentacao. No entanto, quando a fermentacao foi realizada a 7 e a 15 MPa foi possivel atingir o pH caracteristico de kefir. Observou-se ainda que a concentracao de L-acido lactico aumentou ao longo do tempo de fermentacao, sendo que na fermentacao a 7 MPa atingiram-se valores semelhantes aos obtidos na fermentacao a pressao atmosferica. Adicionalmente, quando se aumentou a temperatura de fermentacao (25 e 32 oC), os resultados revelaram um aumento da velocidade fermentativa comparativamente com a fermentacao realizada a temperatura ambiente. No que diz respeito a acidez titulavel, concluiu-se que o aumento da temperatura provocou um aumento da velocidade de formacao de produto (quantificada como acidez titulavel, expressa em acido lactico). Pela analise cinetia, concluiu-se que a pressao diminuiu a velocidade das reacoes envolvidas na fermentacao de kefir. O aumento da temperatura de fermentacao conduziu a uma diminuicao do volume de ativacao (Va), indicando aasim que o processo fermentativo ficou menos sensivel a pressao. Por outro lado, o calculo da energia de ativacao (Ea) mostrou que, em geral, o aumento da pressao levou a que as reacoes de fermentacao do kefir se tornassem mais sensiveis a temperatura (Ea maior). Em conclusao, este estudo mostrou que o efeito combinado da pressao e da temperatura conduziu a alteracoes nos parametros cineticos do processo fermentativo. Sob pressao a combinacao de pressao/temperatura que resultou numa fermentacao mais rapida e numa maior producao de acido foi a 15 MPa/32 oC. Tanto quanto foi possivel encontrar na literatura, este e o primeiro trabalho que estuda o efeito combinado da pressao e da temperatura no processo fermentativo.Kefir is a lightly carbonated, low-alcohol and creamy consistency dairy beverage. It is produced from kefir grains or starter cultures that consist in a mixture of lactic acid bacteria, acetic acid bacteria and yeasts, characterized by having a pH between 4.2 - 4.6. The main purpose of present study was to evaluate the combined effect of pressure and temperature on the fermentation process of kefir production. Thus, fermentation was performed under different pressure and temperature combinations (7, 15, 30 and 50 MPa at ≈ 17 ºC, 15 and 50 MPa at 25 and 32 ºC) and was monitored through variation of pH, titratable acidity, reducing sugars concentration and lactic acid concentration. At room temperature (≈ 17 ºC) the results revealed that the increase of pressure reduce the fermentative rate, since there was a slower variation of pH, titratable acidity and reducing sugars concentration during fermentation time and at 50 MPa there was almost no fermentation. However, when fermentation was carried out at 7 and 15 MPa it was possible to reach the kefir characteristic pH. Besides, it was observed that L-lactic acid concentration increased over fermentation time, and fermentation at 7 MPa reached similar values to those obtained in fermentation at atmospheric pressure. Additionally, when fermentation temperature was increased (25 and 32 ºC), occurred an increase in fermentative rate when compared to fermentation at room temperature. Concerning to titratable acidity, it was concluded that the temperature increase caused an raise in product production rate (quantified as titratable acidity, expressed as lactic acid). Though kinetic analyses, it was concluded that pressure slowed down the reactions involved in kefir fermentation. The increase of fermentation temperature led a decreased in the activation volume (Va), indicating that fermentative process was less sensitive to pressure. On the other hand, the determination of activation energy (Ea) showed that, in general, increase of pressure became the reactions more sensitive to temperature (higher Ea). In conclusion, this study indicated that the combined effect of pressure and temperature led to changes in kinetics parameters of kefir fermentation. Under pressure the pressure/temperature combination that resulted in a faster fermentation and a higher acid production was 15 MPa/32 ºC. As much as possible, in the literature, this is the first work to study the combined effect of pressure and temperature on the fermentation process

Microalgae for urban wastewater treatment and fermentative biohydrogen production

Concerns about climate changes and global water crisis are increasing, considering the low freshwater resources, pollution, and changes in the hydrological cycle. Therefore, water is a precious scarce resource being crucial to develop wastewater treatment and recovery processes to improve water resources management. On the other hand, the problematic of fossil fuels leads to its replacement by biofuels. Thus there are studies [1] to combine wastewater treatment with microalgal biomass as 3rd generation biofuel sources. This study pretends to apply the biorefinery concept to an innovative photobioreactor (PBR) to treat wastewater with microalgae and later valorise the biomass by producing biohydrogen. It is intended to reduce CO2, phosphorus, nitrogen, ammonium and other pollutants presents in wastewater, according EC targets, since microalgae consume the nutrients for growth thus removing them from the wastewater. Within the WW-SIP Life project, a new type of PBR for urban waste water treatment plant (UWWTP) effluents has been designed and will be scaled up. The tubular vertical PBR prototype (150 L) placed outdoor has an air compressor to perform agitation, a membrane module to permeate the treated water and a settler to concentrate the biomass. The results will be used to scale up a PBR of 1500 L. The PBR was fed with primary effluent from Águas da Figueira (PT) UWWTP and inoculated with Chlorella vulgaris, Scenedesmus obliquus and a consortium of microalgae (Consortium C) isolated from the wastewater. The PBR was operated in fed-batch mode and the culture parameters (e.g. pH, air-bubbling, recirculation flow) were optimized. The highest productivity was attained by C. vulgaris (2.4 gL-1day-1) and efficient nutrient removal (>75%) was observed for all algae. The microalgal biomass was then submitted to a nutritional stress for sugar and oil accumulation. Furthermore, the potential of the biomass as substrate for biofuel (bioH2) production by anaerobic fermentation in mesophilic conditions (T=30ºC) was evaluated. Batch trials were conducted in encapsulated glass serum bottles using 2.5 g/L alga and 10% (v/v) of a strain of the bacteria Enterobacter aerogenes. Fermentation kinetics were monitored by biogas analysis with GC-TCD showing that bioH2 production stabilized after around 6h. The specific production was around 45 mL H2/galga. This integrated wastewater treatment/biofuel production approach seems to be promising. In the future the production of other biofuel/biomaterials/added-value compounds will also be considered using microalgae grown in this membrane-based PBR

Escala Eating Assessment Tool 10 na pessoa com Acidente Vascular Cerebral

Background: swallowing disorders often occur in Stroke. The Eating Assessment Tool-10 allows early detection of dysphagia and response to treatment. Objective: To evaluate the metric properties of the Eating Assessment Tool-10 in the person with Stroke that presents swallowing disorders. Method: Systematic Review of Literature based on the recommendations of the Joanna Brigs Institute for the PICo strategy, what are the metric properties of the Eating Assessment Tool-10 in people with Stroke that present a swallowing disorder? The research was carried out using the electronic database platforms: EBSCO, Host, Google Scolar, Cochrane Library Collection, Scielo and Proquest, having identified, selected, evaluated the methodological quality and included the articles that take into account the PRISMA recommendations. Results: Six studies were included that fulfilled the eligibility and methodological quality criteria. Studies on the reproducibility, validity and responsiveness of the Eating Assessment Tool-10 were found. However, this last propertyneeds to be studied in future investigations. The limitation identified was the applicability of the scale in people with cognitive alterations. Conclusions: The Eating Assessment Tool-10 is a reliable, valid and responsive tool for people with stroke that present swallowing disorders.Introducción: Con el Accidente Vascular Cerebral, surgen con frecuencia alteraciones de la deglución. El Eating Assessment Tool-10 es un instrumento que permite detectar precozmente la disfagia y la respuesta al tratamiento. Objetivo: Evaluar las propiedades métricas del Eating Assessment Tool-10 en la persona con Accidente Vascular Cerebral con alteración de la deglución. Método: Revisión Sistemática de la Literatura basada en las recomendaciones del Joanna Brigs Institute para la estrategia PICo, cuáles las propiedades métricas del Eating Assessment Tool-10 en personas con Accidente VascularCerebral con alteración de la deglución. La investigación se realizó utilizando plataformas de bases de datos electrónicas EBSCO, Host, Google Escolar, Cochrane Lybrary Collection, Scielo y Proquest., Habiendo identificado, seleccionados, evaluados en la calidad metodológica e incluidos los artículos teniendo en cuenta las recomendaciones PRISMA. Resultados: Se incluyeron seis estudios que cumplían los criterios de elegibilidad y de calidad metodológica. Se han encontrado estudios sobre la reproducibilidad, validez y responsividad del Eating Assessment Tool-10. Sin embargo,esta última propiedad necesita ser estudiada en futuras investigaciones. La limitación identificada fue en la aplicabilidad de la escala en personas con alteraciones cognitivas. Conclusiones: El Eating Assessment Tool-10 es un test fiable, válido y con responsividad, en las personas con AVC con alteraciones de la deglución.Introdução: Com o Acidente Vascular Cerebral, surgem com frequência alterações da deglutição. O Eating Assessment Tool-10 é um instrumento que permite detetar precocemente a disfagia e a resposta ao tratamento. Objetivo: Avaliar as propriedades métricas do Eating Assessment Tool-10 na pessoa com Acidente Vascular Cerebral com alteração da deglutição. Método: Revisão Sistemática da Literatura baseada nas recomendações do Joanna Brigs Institute para a estratégia PICo, quais a propriedades métricas do Eating Assessment Tool-10 em pessoas com Acidente Vascular Cerebral com alteração da deglutição? A pesquisa foi realizada com recurso a plataformas de bases de dados eletrónicas EBSCO, Host, Google Escolar, Cochrane Lybrary Collection, Scielo e Proquest, tendo sido identificados, selecionados, avaliados na qualidade metodológica e incluídos os artigos de acordo com as recomendações PRISMA. Resultados: Foram incluídos seis estudos que cumpriam os critérios de elegibilidade e de qualidade metodológica. Foram encontrados estudos sobre a reprodutibilidade, validade e responsividade do Eating Assessment Tool-10. Contudo, esta última propriedade necessita de ser estudada em futuras investigações. A limitação identificada foi na aplicabilidade da escala em pessoas com alterações cognitivas. Conclusões: O Eating Assessment Tool-10 é um instrumento fiável, válido e com responsividade, nas pessoas com AVC com alterações da deglutição

Combining urban wastewater treatment with biohydrogen production: An integrated microalgae-based approach

The aim of the present work was the simultaneous treatment of urban wastewater using microalgae and the energetic valorization of the obtained biomass. Chlorella vulgaris (Cv), Scenedesmus obliquus (Sc) and a naturally occurring algal Consortium C (ConsC) were grown in an urban wastewater. The nutrient removals were quite high and the treated water fits the legislation (PT Dec-Lei 236/98) in what concerns the parameters analysed (N, P, COD). After nutrient depletion the microalgae remained two more weeks in the photobioreactor (PBR) under nutritional stress conditions, to induce sugar accumulation (22–43%). The stressed biomass was converted into biohydrogen (bioH2), a clean energy carrier, through dark fermentation by a strain of the bacteria Enterobacter aerogenes. The fermentation kinetics were monitored and fitted to a modified Gompertz model. The highest bioH2 production yield was obtained for S. obliquus (56.8 mL H2/gVS) which was very similar when using the same algae grown in synthetic media

Histone Deacetylase Inhibitors Protect Against Pyruvate Dehydrogenase Dysfunction in Huntington's Disease

Transcriptional deregulation and changes in mitochondrial bioenergetics, including pyruvate dehydrogenase (PDH) dysfunction, have been described in Huntington's disease (HD). We showed previously that the histone deacetylase inhibitors (HDACIs) trichostatin A and sodium butyrate (SB) ameliorate mitochondrial function in cells expressing mutant huntingtin. In this work, we investigated the effect of HDACIs on the regulation of PDH activity in striatal cells derived from HD knock-in mice and YAC128 mice. Mutant cells exhibited decreased PDH activity and increased PDH E1alpha phosphorylation/inactivation, accompanied by enhanced protein levels of PDH kinases 1 and 3 (PDK1 and PDK3). Exposure to dichloroacetate, an inhibitor of PDKs, increased mitochondrial respiration and decreased production of reactive oxygen species in mutant cells, emphasizing PDH as an interesting therapeutic target in HD. Treatment with SB and sodium phenylbutyrate, another HDACI, recovered cell viability and overall mitochondrial metabolism in mutant cells. Exposure to SB also suppressed hypoxia-inducible factor-1 (HIF-1α) stabilization and decreased the transcription of the two most abundant PDK isoforms, PDK2 and PDK3, culminating in increased PDH activation in mutant cells. Concordantly, PDK3 knockdown improved mitochondrial function, emphasizing the role of PDK3 inactivation on the positive effects achieved by SB treatment. YAC128 mouse brain presented higher mRNA levels of PDK1-3 and PDH phosphorylation and decreased energy levels that were significantly ameliorated after SB treatment. Furthermore, enhanced motor learning and coordination were observed in SB-treated YAC128 mice. These results suggest that HDACIs, particularly SB, promote the activity of PDH in the HD brain, helping to counteract HD-related deficits in mitochondrial bioenergetics and motor function.SIGNIFICANCE STATEMENT The present work provides a better understanding of mitochondrial dysfunction in Huntington's disease (HD) by showing that the pyruvate dehydrogenase (PDH) complex is a promising therapeutic target. In particular, the histone deacetylase inhibitor sodium butyrate (SB) may indirectly (through reduced hypoxia-inducible factor 1 alpha stabilization) decrease the expression of the most abundant PDH kinase isoforms (e.g., PDK3), ameliorating PDH activity and mitochondrial metabolism and further affecting motor behavior in HD mice, thus constituting a promising agent for HD neuroprotective treatment.FCT, Santa Casa da Misericórdia de Lisboa (SCML), Fundação Luso-Americana para o Desenvolvimento (FLAD) Life Scienc

A strategy to overcome multispecies vascular catheter-related infections

Funding Information: The authors thank Fundação para a Ciência e Tecnologia (FCT) Portugal, for the financial support under the Project PTDC/BTM-SAL/29335/2017 . Portugal 2020 for the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa RNEM ) is also acknowledged. The authors also acknowledge the Designer Nuno Monge for the artwork, Isabel Dias Nogueira (Microlab, Instituto Superior Técnico, Lisbon University) for the technical assistance with the SEM analysis, Andreia Bento for the assistance with the UHPLC-MS equipment (iMed.Ulisboa) and Professor Maria José Ferreira (FFULisboa) for allowing the use of the automatic flash chromatography equipment. Funding Information: The authors thank Fundação para a Ciência e Tecnologia (FCT) Portugal, for the financial support under the Project PTDC/BTM-SAL/29335/2017. Portugal 2020 for the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa RNEM) is also acknowledged. The authors also acknowledge the Designer Nuno Monge for the artwork, Isabel Dias Nogueira (Microlab, Instituto Superior Técnico, Lisbon University) for the technical assistance with the SEM analysis, Andreia Bento for the assistance with the UHPLC-MS equipment (iMed.Ulisboa) and Professor Maria José Ferreira (FFULisboa) for allowing the use of the automatic flash chromatography equipment. Publisher Copyright: © 2022In clinic there is a demand to solve the drawback of medical devices multispecies related infections. Consequently, different biomaterial surfaces, such as vascular catheters, urgently need improvement regarding their antifouling/antimicrobial properties. In this work, we covalently functionalized medical grade polydimethylsiloxane (PDMS) with antimicrobial rhamnolipids to investigate the biomaterial surface activity towards mono and dual species biofilms. Preparation of surfaces with “piranha” oxidation, followed by APTES bonding and carbodiimide reaction with rhamnolipids effectively bonded these compounds to PDMS surface as confirmed by FTIR-ATR and XPS analysis. Generated surfaces were active towards S. aureus biofilm formation showing a 4.2 log reduction while with S. epidermidis and C. albicans biofilms a reduction of 1.2 and 1.0 log reduction, respectively, was observed. Regarding dual-species testing the higher biofilm log reduction observed was 1.9. Additionally, biocompatibility was assessed by cytocompatibility towards human fibroblastic cells, low platelet activation and absence of vascular irritation. Our work not only sheds light on using covalently bonded rhamnolipids towards dual species biofilms but also highlights the biocompatibility of the obtained PDMS surfaces.publishersversionpublishe

A neurophysiological signature of dynamic emotion recognition associated with social communication skills and cortical gamma-aminobutyric acid levels in children

IntroductionEmotion recognition is a core feature of social perception. In particular, perception of dynamic facial emotional expressions is a major feature of the third visual pathway. However, the classical N170 visual evoked signal does not provide a pure correlate of such processing. Indeed, independent component analysis has demonstrated that the N170 component is already active at the time of the P100, and is therefore distorted by early components. Here we implemented, a dynamic face emotional paradigm to isolate a more pure face expression selective N170. We searched for a neural correlate of perception of dynamic facial emotional expressions, by starting with a face baseline from which a facial expression evolved. This allowed for a specific facial expression contrast signal which we aimed to relate with social communication abilities and cortical gamma-aminobutyric acid (GABA) levels.MethodsWe recorded event-related potentials (ERPs) and Magnetic Resonance (MRS) measures in 35 typically developing (TD) children, (10–16 years) sex-matched, during emotion recognition of an avatar morphing/unmorphing from neutral to happy/sad expressions. This task allowed for the elimination of the contribution low-level visual components, in particular the P100, by morphing baseline isoluminant neutral faces into specific expressions, isolating dynamic emotion recognition. Therefore, it was possible to isolate a dynamic face sensitive N170 devoid of interactions with earlier components.ResultsWe found delayed N170 and P300, with a hysteresis type of dependence on stimulus trajectory (morphing/unmorphing), with hemispheric lateralization. The delayed N170 is generated by an extrastriate source, which can be related to the third visual pathway specialized in biological motion processing. GABA levels in visual cortex were related with N170 amplitude and latency and predictive of worse social communication performance (SCQ scores). N170 latencies reflected delayed processing speed of emotional expressions and related to worse social communication scores.DiscussionIn sum, we found a specific N170 electrophysiological signature of dynamic face processing related to social communication abilities and cortical GABA levels. These findings have potential clinical significance supporting the hypothesis of a spectrum of social communication abilities and the identification of a specific face-expression sensitive N170 which can potentially be used in the development of diagnostic and intervention tools