137 research outputs found

    Production of natural nano-gel from pineapple polysaccharides complexes for controlled release of bioactive compounds

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    São Paulo School of Advanced Sciences on Reverse Engineering of Processed Foods[Excerpt] Pineapple (Ananas cosmosus) is the third most important tropical fruit in world production, seventy percent of the pineapple produced in the world is consumed as fresh fruit. In the agro-food sector, several materials are eliminated as waste throughout production and processing chain. These residues (skins, seed and pulp remnants) contain high content of bioactive compounds, but in generally not directly available, and for that reason is necessary to extract and characterize the feasible bioactive compounds (do Espírito Santo et al., 2012). Therefore, the study of the wastes and by-products generated during pineapple production and post-harvest processing is relevant and interesting to valorise them and reduce their environmental impact. The development of vehicles using these residues that deliveries the compounds as well promotes the maintenance of bioactivity, has been widely study, but lacks the search of new structures that could be easily used in food industry. Therefore, the focus of this research work was to developed nanocarriers using pineapple residues to extract pineapple polysaccharides for delivery of bioactive compounds. Frozen pineapple wastes were submitted to a milling and pressing processes, creating a pineapple juice and a solid semi-dried extract. Characterization was made for both parts comprised proteins, sugars, fibers, lipids and polyphenol contents. The soluble fraction was fractionated by centrifuge filter tubes with cut-off of 50 kDa and after by cut-off of 3 kDa, and three fractions were obtained: above 50 kDa, between 50 and 3 kDa and below 3 kDa. The insoluble part was submitted to hot aqueous extraction. The supernatant and the pellet of this extraction were separated and studied separately. Pineapple polysaccharides were identified and quantified by HPLC method and phenol-sulphuric method, respectively. [...]info:eu-repo/semantics/publishedVersio

    Pseudomonas aeruginosa PAO 1 in vitro timekill kinetics using single phages and phage formulationsmodulating death, adaptation, and resistance

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    Pseudomonas aeruginosa is responsible for nosocomial and chronic infections in healthcare settings. The major challenge in treating P. aeruginosa-related diseases is its remarkable capacity for antibiotic resistance development. Bacteriophage (phage) therapy is regarded as a possible alternative that has, for years, attracted attention for fighting multidrug-resistant infections. In this work, we characterized five phages showing different lytic spectrums towards clinical isolates. Two of these phages were isolated from the Russian Microgen Sextaphage formulation and belong to the Phikmvviruses, while three Pbunaviruses were isolated from sewage. Different phage formulations for the treatment of P. aeruginosa PAO1 resulted in diversified timekill outcomes. The best result was obtained with a formulation with all phages, prompting a lower frequency of resistant variants and considerable alterations in cell motility, resulting in a loss of 73.7% in swimming motility and a 79% change in swarming motility. These alterations diminished the virulence of the phage-resisting phenotypes but promoted their growth since most became insensitive to a single or even all phages. However, not all combinations drove to enhanced cell killings due to the competition and loss of receptors. This study highlights that more caution is needed when developing cocktail formulations to maximize phage therapy efficacy. Selecting phages for formulations should consider the emergence of phage-resistant bacteria and whether the formulations are intended for short-term or extended antibacterial application.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit. S.S. acknowledges funding by FCT through the individual scientific employment program contract (2020.03171.CEECIND).info:eu-repo/semantics/publishedVersio

    Biological extraction of bromelain from pineapple byproducts

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    [Excerpt] Isolation and purification of valuable compounds are very important processes to valorize agro-food byproducts. Currently, protein extraction and development of environmentally friendly technologies are industrially relevant topics [1]. Among the extracted proteins from byproducts proteases are a relevant group for industrial applications. These enzymes are a class of hydrolytic enzymes capable of cleaving the peptide bonds of proteins chains and are essential in physiological processes [2]. (...

    Natamycin-loaded poly(n-isopropylacrylamide) nanohydrogels for smart edible packaging : development and characterization

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    The development of new formulations for antimicrobial agents release has attracted great attention due to the possibility of using such formulations in several applications (e.g. food packaging and surface treatments in biomedical devices). Smart packaging appears in the last years as one of the most promissory application to food packaging in order to enhance the capacity to maintain food quality and safety. Moreover, edible packaging, using edible and biodegradable biopolymers, has been stated as one of the promises in packaging science (e.g. fresh-cut products, cheese, fruits, fish). Based on this and in the fact that no work has been reported with the incorporation of smart nanohydrogels in edible packaging, a smart delivery device consisting in poly(N-isopropylacrylamide) nanohydrogels and polysaccharide- based films was developed. Polysaccharide-based films with and without the incorporation of natamycin-loaded poly(N-isopropylacrylamide) nanohydrogels were charactherized in terms of: transport (water vapour, oxygen and carbon dioxide permeabilities) and mechanical properties (tensile strength and elongation-at-break), opacity, water sensitivity (moisture content and contact angle) and thermal properties (differential scanning calorimetry - DSC and thermogravimetric analyses - TGA). Chemical interactions were studied by means of Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy was used to verify the presence of nanohydrogel in the film matrix. [...

    Characterization of PHBV films loaded with FO1 bacteriophage using polyvinyl alcohol-based nanofibers and coatings: a comparative study

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    There is a current demand for novel active food packaging solutions using biodegradable materials and no chemical antimicrobial compounds, to ensure food quality and safety. This work involved the incorporation of Salmonella Enteritidis bacteriophage Felix O1, for potential use as an anti-Salmonella agent, into polyvinyl alcohol (PVOH) coatings and fibers deposited by casting and electrospinning on polyhydroxybutyrate/polyhydroxyvalerate (PHBV) films. PHBV films (pristine, with coating, and with nanofibers) were characterized in terms of water sensitivity, mechanical performance, morphology, and thermal properties. Additionally, X-ray diffraction and Fourier Transform Infrared Spectroscopy were performed to assess possible chemical modifications on PHBV films after PVOH deposition and the presence of bacteriophage. PVOH increased the moisture content from 5.98% (PHBV) to 8.94% and 8.28% for PHBV/coating films and PHBV/nanofiber films respectively, increased the solubility from 0% (PHBV) to 30.32% (PHBV/coating films) and to 32.42% (PHBV/nanofiber films), and increased the hydrophilicity of the films (contact angle of 76.31° for PHBV, 64.01° for PHBV/coating films and 30.90° for PHBV/nanofiber films), leading to an increased water affinity of their surface. Felix O1 was successfully added and maintained antimicrobial activity (106 titer) after the formation of the coating and nanofibers, demonstrating that these solutions can potentially be used in future packaging materials to avoid Salmonella contamination.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER 006684). This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agree ment No 713640. Maria Jos´e Costa is recipient of a fellowship supported by a Doctoral Program (SFRH/BD/122897/2016) funded by the Portu guese Foundation for Science and Technology (FCT, POPH-QREN and FSE Portugal). All the bacteriophage solutions were kindly supplied by Micreos (Netherlands).info:eu-repo/semantics/publishedVersio

    Bacteriophages for chronic wound treatment: from traditional to novel delivery systems

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    The treatment and management of chronic wounds presents a massive financial burden for global health care systems, with significant and disturbing consequences for the patients affected. These wounds remain challenging to treat, reduce the patients’ life quality, and are responsible for a high percentage of limb amputations and many premature deaths. The presence of bacterial biofilms hampers chronic wound therapy due to the high tolerance of biofilm cells to many first- and second-line antibiotics. Due to the appearance of antibiotic-resistant and multidrug-resistant pathogens in these types of wounds, the research for alternative and complementary therapeutic approaches has increased. Bacteriophage (phage) therapy, discovered in the early 1900s, has been revived in the last few decades due to its antibacterial efficacy against antibiotic-resistant clinical isolates. Its use in the treatment of non-healing wounds has shown promising outcomes. In this review, we focus on the societal problems of chronic wounds, describe both the history and ongoing clinical trials of chronic wound-related treatments, and also outline experiments carried out for efficacy evaluation with different phage-host systems using in vitro, ex vivo, and in vivo animal models. We also describe the modern and most recent delivery systems developed for the incorporation of phages for species-targeted antibacterial control while protecting them upon exposure to harsh conditions, increasing the shelf life and facilitating storage of phage-based products. In this review, we also highlight the advances in phage therapy regulation.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 713640. A.M.P. acknowledges the Portuguese Foundation for Science and Technology (FCT) for the grant SFRH/BD/138138/2018. The authors also thank NORTE 2020 (2014–2020 North Portugal Regional Operational Programme) and the ERDF (European Regional Development Fund) under the Grant NORTE‐45‐2015‐02. M.B.L also thanks FCT for the grant PT‐DZ/0004/2015, as well as the 2014– 2020 INTERREG Cooperation Programme Spain–Portugal (POCTEP) through the project 0624_2IQBIONEURO_6_E.info:eu-repo/semantics/publishedVersio

    Oleogels for the development of healthier meat-based food products

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    Obesity is a disease that can be addressed through preemptive actions and behavioral changes like proper diet and exercise. In connection with obesity, cardiovascular disease can become an additional and severe problem. Scientific data regarding western diets, recons that dietary lipids account for over 35% of the daily caloric content of an individual's diet. Because of this it would be valuable to have alternatives with anti-obesogenic effects [1]. Another significant dietary factor in the prevention of obesity is a balanced omega-6/omega-3 ratio intake, that can be achieved through the consumption of enriched foods. Food innovation is driven by food products that contribute to improve health. These products are known as functional foods and they can be used strategically in order to avoid or battle the above-mentioned disorders. Functional oleogels were produced using enriched alpha-linolenic linseed oil with plant sterols (in hamburger production) and beeswax (in pate production) as oil gelators. Oleogels with 8 % (w/w) of gelator were used in both products as replaces of saturated fat. The range of fat replacement went from 25 to 75 % in hamburgers (H-25 and H-75) and 30 to 60 % in pate (P-30 and P-60). Tests with hamburgers showed that consumer acceptance and preference was directed towards the control samples. Nevertheless, the hamburgers samples with less amount of oleogel (H-25) were classified positively in both the acceptance and preference tests. Those same two sets of samples (control an H-25) showed similar textural characteristics. In the pate sensorial tests, the control sample was the much-liked one, however after data observation, the overall score for the P-30 sample still.Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). Artur Martins is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 -Programa Operacional Regional do Norte. José M. Lorenzo, is a member of the MARCARNE network, funded by CYTED (ref. 116RT0503)info:eu-repo/semantics/publishedVersio

    Optimisation of the extraction and purification of chondroitin sulphate from head by-products of Prionace glauca by environmental friendly processes

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    8 páginas, 3 figuras, 3 tablasThe goal of the present work was to optimise the different environmental friendly processes involved in the extraction and purification of chondroitin sulphate (CS) from Prionace glauca head wastes. The experimental development was based on second order rotatable designs and evaluated by response surface methodology combined with a previous kinetic approach. The sequential stages optimised were: (1) the enzymatic hydrolysis of head cartilage catalysed by alcalase (55.7 °C/pH 8.2); (2) the chemical treatment of enzyme hydrolysates by means of alkaline-hydroalcoholic saline solutions (NaOH: 0.54 M, EtOH: 1.17 v, NaCl: 2.5%) to end the protein hydrolysis and to precipitate and selectively redissolve CS versus the peptidic material and (3) the selective purification and concentration of CS and the concomitant protein permeation of extracts which were obtained from previous treatment using ultrafiltration and diafiltration (UF–DF) technologies at two different cut-offsFinancial support from projects MARMED 2011-1/164 (Atlantic Area Programme, EU), 0687_NOVOMAR_1_P (POCTEP Programme, EU) and iSEAS LIFE13 ENV/ES/000131 (LIFE+ Programme, EU) is acknowledgedPeer reviewe

    Creating functional nanostructures: Encapsulation of caffeine into α-lactalbumin nanotubes

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    This work evaluated the stability and functionality of nanotubes obtained from α-lactalbumin (α-LA). α-LA nanotubes' structure was highly stable during a freeze-drying process but not after grinding. The ability of α-LA nanotubes to encapsulate caffeine, used as a model molecule, was evaluated. α-La nanotubes were highly effective for this purpose as encapsulation efficiency (%EE) was near 100% and loading capacity (%LC) near 10% at 1.5/20 and 2/20 ratios (caffeine/α-LA, w/w). α-LA nanotubes' structure was not affected by the presence of caffeine. Also, in general, refrigeration temperatures and neutral or alkaline conditions, under which the adverse effect of chelating agents was prevented, helped to stabilise α-LA nanotubes' structure and maintain caffeine encapsulated. At 8 °C and pH 7.5, in the presence of 75 μg mL− 1 of EDTA, > 50% of the caffeine remained encapsulated into α-LA nanotubes.Clara Fuciños gratefully acknowledge her Post-Doctoral grant (I2C 2014) from Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia, Spain). Pablo Fuciños gratefully acknowledges his Marie Curie COFUND Postdoctoral Research Fellowship (Project No: 600375. NanoTRAINforGrowth - INL Fellowship programme in nanotechnologies for biomedical, environment and food applications). This study was supported by the Fundação para a Ciência e a Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
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