5,985 research outputs found

    Production de vins mousseux a partir de "Vinhos Verdes" blancs monovarietaux

    Get PDF
    On a fait l'étude comparative de vins mousseux élaborés à partir de vins de base issus de cinq cépages recommandés pour la Région: Loureiro, Trajadura, Avesso, Pedernã et Azal blanc, en ce qui concerne les propriétés organoleptiques. Les vins de base ont été produits selon le processus utilisé dans la Région -égrappage, pressurage, débourbage et fermentation alcoolique-, ayant été soumis aussi à une fermentation malolactique. La prise de mousse a été effectuée en bouteille, avec des levures immobilisées en billes d'alginate, pendant cinq mois à 14 °C. Les propriétés sensorielles des vins ont été évaluées en utilisant des fiches classificatrices et descriptives, par une chambre de neuf dégustateurs expérimentés. Le traitement statistique des résultats, effectué par le logiciel SPSS, a été fait en recourrant à l'analyse de variance. On a trouvé quelques différences parmi les cinq vins mousseux surtout en ce qui concerne l'aspect du cordon et l'arôme. Cependant, tous ces vins ont obtenu des classifications globales au-dessus de l'acceptable, atteignant parfois l'excellent. Ces résultats préliminaires ainsi obtenus, basés sur les caractéristiques organoleptiques, suggèrent la possibilité d'obtenir des vins mousseux de qualité à partir des cépages de "Vinho Verde"

    How to break access control in a controlled manner

    Get PDF
    The Electronic Medical Record (EMR) integrates heterogeneous information within a Healthcare Institution stressing the need for security and access control. The Biostatistics and Medical Informatics Department from Porto Faculty of Medicine has recently implemented a Virtual EMR (VEMR) in order to integrate patient information and clinical reports within a university hospital. With more than 500 medical doctors using the system on a daily basis, an access control policy and model were implemented. However, the healthcare environment has unanticipated situations (i.e. emergency situations) where access to information is essential. Most traditional policies do not allow for overriding. A policy that allows for Break-The-Glass (BTG) was implemented in order to override access control whilst providing for non-repudiation mechanisms for its usage. The policy was easily integrated within the model confirming its modularity and the fact that user intervention in defining security procedures is crucial to its successful implementation and use

    Peptide extract from spent yeast improves resistance of Saccharomyces cerevisiae to oxidative stress

    Get PDF
    Yeast cells face various stress factors during industrial fermentations, since they are exposed to harsh environmental conditions, which may impair biomolecules productivity and yield. In this work, the use of an antioxidant peptide extract obtained from industrial spent yeast was explored as supplement for Saccharomyces cerevisiae fermentation to prevent a common bottleneck: oxidative stress. For that, a recombinant yeast strain, producer of β-farnesene, was firstly incubated with 0.5 and 0.7 g/L peptide extract, in the presence and absence of hydrogen peroxide (an oxidative stress inducer), for 1–5 h, and then assayed for intracellular reactive oxygen species, and growth ability in agar spot assays. Results showed that under 2 mM H2O2, the peptide extract could improve cells growth and reduce reactive oxygen species production. Therefore, this antioxidant effect was further evaluated in shake-flasks and 2-L bioreactor batch fermentations. Peptide extract (0.7 g/L) was able to increase yeast resistance to the oxidative stress promoted by 2 mM H2O2, by reducing reactive oxygen species levels between 1.2- and 1.7-fold in bioreactor and between 1.2- and 3-fold in shake-flask fermentations. Moreover, improvements on yeast cell density of up to 1.5-fold and 2-fold, and on biomolecule concentration of up to 1.6-fold and 2.8-fold, in bioreactor and shake-flasks, respectively, were obtained. Thus, culture medium supplementation with antioxidant peptide extracted from industrial spent yeast is a promising strategy to improve fermentation performance while valuing biomass waste. This valorization can promote a sustainable and eco-friendly solution for the biotechnology industry by the implementation of a circular economy model.info:eu-repo/semantics/publishedVersio

    Spent yeast valorization for food applications: effect of different extraction methodologies

    Get PDF
    Over the years, synthetic biology has been growing with the use of engineered yeast strains for the production of sustainable ingredients to meet global healthcare, agriculture, manufacturing and environmental challenges. However, as seen from the brewing industry perspective, these processes generate a substantial amount of spent yeast that contains high nutritional value related to its high protein content, showing its potential to be used as an alternative protein source. Taking into account the rising demand for protein because of the growth in the global population, the present study aims to produce peptide-rich extracts by different potentially scalable and sustainable methodologies in a circular economy approach for the food and nutraceutical industries. The results demonstrated that extraction from genetically modified strains allowed the production of extracts with an excellent nutritional profile and low molecular weight peptides. Furthermore, autolysis was shown to be a potential sustainable approach for this production, though other green metrics need to be explored in order to establish this process at an industrial level.info:eu-repo/semantics/publishedVersio

    Development of dioctadecyldimethylammonium bromide/monoolein liposomes for gene delivery

    Get PDF
    The artificial introduction of nucleic acids (NA) into mammalian cells (transfection) has become, in recent years, a well-established procedure in basic and applied research, which allowed the study of gene function and regulation. The advances in this area have made possible the use of these methods for gene-based medicines, which constitute alternative therapeutic approaches. One of the most prominent methods is lipofection that uses cationic liposome/NA complexes (a.k.a. lipoplexes) for the complexation, transport and release of therapeutic sequences into target cells. Although yielding lower transfection efficiencies compared with viral gene delivery, lipofection vectors are much safer for medical applications because no significant mutational or toxicological risk exist. Dioctadecyldimethylammonium Bromide (DODAB)/Monoolein (MO) liposomes have recently been described as a new promising alternative to common transfection reagents, due to the pioneering application of MO as helper lipid in lipoplex formulations. In this chapter, we will review the effect of MO on the physicochemical properties of DODAB/MO liposomes and pDNA/DODAB/MO lipoplexes. How lipoplex properties may affect the interaction with different extracellular components and their cell uptake and trafficking will be discussed. The importance of lipoplex biocompatibility towards efficient gene therapy will also be approached presenting pDNA/DODAB/MO system as a lipoplex model, supporting the use of MO as new helper lipid in lipofection.FCTCOMPETEThis work was supported by FCT research project PTDC/QUI/69795/2006, which is cofunded by the program COMPETE from QREN with co-participation from the European Community fund FEDER; CFUM [PEst-C/FIS/UI0607/2011]; CBMA [Pest C/BIA/UI4050/2011]; J.P.N. Silva holds a PhD Grant (SFRH/BD/46968/2008); A. C.N. Oliveira holds a PhD grant (SFRH/BD/68588/2010)

    Valorisation of protein-rich extracts from spent brewer’s yeast (Saccharomyces cerevisiae): an overview

    Get PDF
    As one of the main brewing by-products, Saccharomyces cerevisiae extracts (from spent yeast) have been commercialized as food supplement for years. Among their several claims, the application as protein source is highlighted. In fact, their high protein content (about 45–60%) including essential amino acids with high biological value, safety and low cost are primarily responsible for their spreading in agri-food sector. Meanwhile, cosmetic and health sectors have been working on yeast bioactive peptides because of their antihypertensive, antioxidant and antimicrobial properties, among others. Several studies related to valorisation of S. cerevisiae are currently ongoing, aiming to create novel products and optimize production processes. The present review aims to provide an overview from production of protein-rich extracts from S. cerevisiae to their chemical characterisation, detailing protein extraction, isolation and purification processes, as well as characterisation methods for the final extracts. Graphical abstract: [Figure not available: see fulltext.]info:eu-repo/semantics/acceptedVersio

    Differences in chemical composition and antioxidant activity of three propolis samples collected in the same apiary

    Get PDF
    Financial support provided by FCT (PD/BD/128276/2017), under the Doctoral Programme Agrichains - PD/00122/2012

    Synthesis of bio-based Polyester from microbial lipidic residue intended for biomedical application

    Get PDF
    In the last decade, selectively tuned bio-based polyesters have been increasingly used for their clinical potential in several biomedical applications, such as tissue engineering, wound healing, and drug delivery. With a biomedical application in mind, a flexible polyester was produced by melt polycondensation using the microbial oil residue collected after the distillation of β-farnesene (FDR) produced industrially by genetically modified yeast, Saccharomyces cerevisiae. After characterization, the polyester exhibited elongation up to 150% and presented Tg of −51.2 °C and Tm of 169.8 °C. In vitro degradation revealed a mass loss of about 87% after storage in PBS solution for 11 weeks under accelerated conditions (40 °C, RH = 75%). The water contact angle revealed a hydrophilic character, and biocompatibility with skin cells was demonstrated. 3D and 2D scaffolds were produced by salt-leaching, and a controlled release study at 30 °C was performed with Rhodamine B base (RBB, 3D) and curcumin (CRC, 2D), showing a diffusion-controlled mechanism with about 29.3% of RBB released after 48 h and 50.4% of CRC after 7 h. This polymer offers a sustainable and eco-friendly alternative for the potential use of the controlled release of active principles for wound dressing applications.info:eu-repo/semantics/publishedVersio

    Quercetin-biapigenin nanoparticles are effective to penetrate the blood–brain barrier

    Get PDF
    Search for efficient therapeutic agents for central nervous system (CNS) disorders has been extensive. Nevertheless, blood-brain barrier (BBB) is an obstacle that prevents the majority of compounds to act in these diseases. It is, thus, of extreme relevance the BBB overcome, in order to deliver a drugs therapeutically active concentration to the action site, with the least losses and interaction with other organs, tissues, or cells. The present study aimed to investigate the potential protective effect of quercetin-biapigenin encapsulated into poly(Ɛ-polycaprolactone) (PCL) nanoparticles against t-BOOH-induced oxidative stress in several brain cell lines, as well as evaluate the permeability of those active molecules through an in vitro BBB model. The three cell lines under study (BV-2, hcmec/D3, and U87) presented different reactions to t-BOOH. In general, quercetin-biapigenin PCL-loaded nanoparticles were able to minimize compound toxicity they convey, regardless the cell line. Quercetin-biapigenin PCL-loaded nanoparticles (Papp of approximately 80 × 10-6 cm/s) revealed to be more permeable than free compounds (Papp of approximately 50 × 10-6 cm/s). As of our knowledge, this is the first report of quercetin-biapigenin PCL-loaded nanoparticle activity in brain cells. It is also the first determining its permeability through BBB, as an effective nanocarrier for brain delivery.info:eu-repo/semantics/publishedVersio
    corecore