Carboxymethyl cellulose/lignin blended films: physicochemical and antioxidant properties

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Carboxymethyl cellulose-based films: Effect of organosolv lignin incorporation on physicochemical and antioxidant properties

Organosolv lignin was incorporated in carboxymethyl cellulose (CMC)-based films as a reinforcing and bioactive agent. Films were produced by the casting method using compatible and environmentally friendly solvents. The incorporation of lignin in CMC-based films was evaluated in term of morphology, physicochemical, barrier, mechanical and antioxidant properties. Solubility tests showed that lignin improved the water resistance of the films for approx. 60%. This behavior was also observed for the water vapor permeability, achieving a 20% reduction. Morphological characteristics suggested low compatibility between organosolv lignin and CMC matrix, revealed by the small aggregates homogeneously distributed in the film, through scanning electron microscopy, related to the self-assembly behavior of lignin. CMC/lignin-based films also presented higher thermal stability. Fourier transform infrared spectroscopy showed that incorporation of lignin led to small changes in the film's structure. Finally, organosolv lignin proved to be a promising material for the development of active CMC-based films due to its demonstrated antioxidant activity that can be useful to pack food products that suffer from undesirable oxidation reactions.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Nanospraydryer for the production of sub-micro particles based on bovine lactoferrin

This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit and COMPETE 2020 (POCI-01-0145- FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Arlete M. Marques (SFRH/BD/132911/2017) is the recipient of a fellowship from Fundação para a Ciência e Tecnologia (FCT, Portugal)info:eu-repo/semantics/publishedVersio

Ultrasonication processing for the production of plant-based nanoemulsions

Plant-derived proteins have been emerging and growing in interest over the past few years, due to their interesting properties and the trend to replace animal-derived proteins [1]. Ultrasonication processing can be used to develop nanoemulsions based on plant proteins that are kinetically stabilized by their small dimension, unlike classic emulsions [2]. In this work, oil-in-water nanoemulsions were produced through high-speed homogenization, followed by ultrasonic homogenization (US), using different plant-derived proteins, including potato (Solanum tuberosum), lupin (Lupinus angustifolius), pea (Pisum sativum), chickpea (Cicer arietinum) and faba bean (Vicia faba) protein as emulsifiers. A central composite rotatable experimental design was used to evaluate the influence of three independent variables: water/oil ratio (65-75% of water), protein content (1-6%) and US time (1-7 min) on the size average (by intensity) and polydispersity index (PDI) of the nanoemulsions. A total of 17 experiments were performed with 14 three-level experimental points, and 3 replicates at the central point. The effect of the US time (0, 3, 4.5 and 6 min) in the potato and lupin proteins primary and secondary structures were analysed through SDS-PAGE electrophoresis and circular dichroism, respectively. Results showed that the use of potato, lupin and pea proteins lead to the formation of stable nanoemulsions, while chickpea and faba bean proteins resulted in non-stable nanoemulsions, with phase separation. The smallest mean droplet size for potato protein was 439.9 nm and PDI value 0.464 [21:73 (w/w) oil/water ratio, 6% of protein and 6 min of US]. The smallest mean droplet size for lupin protein was 505.5 nm and PDI value 0.434, and for pea protein the droplet size was 551.3 nm and PDI value 0.249 [23.6:73 (w/w) oil/water ratio, 3.4% of protein and 6 min of US]. Electrophoresis results show that for native potato and lupin samples the ultrasonication did not induce significant changes in the protein pattern, indicating that the US treatment did not modify the primary structure. Regarding the second structure, US did not change the secondary structure of potato protein but induced a slight increase of -helix for all US treatments for lupin protein. Stable nanoemulsions can be developed using plant-derived proteins and ultrasonication, foreseeing different applications in the food industry.This study was supported by the project cLabel+ (POCI-01-0247-FEDER-046080) cofinanced by Compete 2020, Lisbon 2020, Portugal 2020 and the European Union, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Análise antimicrobiana de bacteriófagos incorporados em estruturas de base biológica

Dissertação de mestrado integrado em Engenharia Biológica (área de especialização em Tecnologia Química e Alimentar)Recently, edible packaging materials experienced a notable growth, being expected an important impact in the food industry in the next years. Also, bacteriophages have been recognized for their potential as biotherapeutic agents to control bacterial growth, and their use in food industry to control microbiogical growth has been presented as one of the solutions to maintain food quality. The main aim of this work was the functionalization of edible packaging materials with the use of phages. For the development of edible packaging, different types (Protanal SF 120RB; Protanal CR 8223; Protanal LFR 5/60; Protanal GP 1320 and Protanal Manugel) and concentrations (2.5 g/L, 5 g/L, 7.5 g/L, 10 g/L and 15 g/L) of sodium alginate were evaluated, being a concentration of 10 g/L of alginate CR 8223 and Manugel sellected. The produced films were crosslinked with different concentrations of CaCl2 (0 g/L, 10 g/L, 12.5 g/L and 15 g/L). The films were characterized in terms of moisture content, solubility, contact angle, isothermic adsorption, swelling behaviour, colour and opacity, and mechanical properties (TS and EB), being their chemical structure studied by Fourier Transform Infrared (FTIR) spectroscopy. During characterization of CR 8223 and Manugel alginate films, it was possible to conclude that crosslinking has a significant effect on alginate structure and properties. Characterization of films allows to conclude that crosslinking decreases film thickness and the moisture content of films. It was also possible to notice that crosslinking does not change the films colour, but make them stronger and insoluble with a high swelling index. After the characterization, a concentration of 10 g/L of CR 8223 alginate was selected for phages incorporation, being crosslinked with 10 g/L of CaCl2. The choice was based on swelling and solubility films properties. Antimicrobial activity of alginate films with entrapped phages showed that phage ΦIBB-PF7A can be incorporated in alginate-based films and maintain its activity, leading to a bacterial decrease of 4 log for the multiplicity of infection (MOI) of 10 in the first 24 h. It was also possible to confirm that phages are released onto chicken meat, leading to a decrease of Pseudomonas fluorescens contamination. Results show that alginate-based films with phages can be used to control bacterial growth in meat products, presenting a potential interest for the food industry.As embalagens edíveis têm crescido notavelmente nos últimos anos, esperando-se nos próximos anos um grande impacto na indústria alimentar. Para além disso os bacteriófagos têm sido reconhecidos pelo seu potencial como agentes bio-terapêuticos no controlo do crescimento de bactérias e por isso têm vindo a ser apresentados como uma das soluções para o controlo do crescimento bacteriano na indústria alimentar. O principal objetivo deste trabalho foi a funcionalização de embalagens com a incorporação de fagos em bio-estruturas. Para desenvolver as embalagens edíveis, diferentes tipos (Protanal SF 120RB; Protanal CR 8223; Protanal LFR 5/60; Protanal GP 1320 and Protanal Manugel) e concentrações (2,5 g/L, 5 g/L, 7,5 g/L, 10 g/L and 15 g/L) de alginato de sódio foram avaliados, tendo sido selecionados os alginatos CR 8223 e o Manugel com uma concentração de 10 g/L. Os filmes produzidos foram reticulados com diferentes concentrações de solução CaCl2 (0 g/L, 10 g/L, 12,5 g/L e 15 g/L). Os filmes foram caraterizados em termos de humidade, solubilidade, grau de inchamento, ângulos de contato, isotérmicas de adsorção, cor e opacidade e propriedades mecânicas (resistência à tração e elongação à rutura), as estruturas quimícas foram estudadas através da espectroscopia por infravermelho com transformada de Fourier (FTIR). Durante a caracterização dos filmes de alginato CR 8223 e Manugel, foi possível concluir que a reticulação tem um efeito significativo na estrutura e propriedades destes. A caracterização dos filmes permitiu concluir que a reticulação diminui a espessura dos filmes, bem como a humidade. Também foi possível concluir que a reticulação não altera a cor dos filmes, mas torna-os mais fortes, insolúveis e com uma grande capacidade de absorção. Depois de caracterizados, o alginato CR 8223 com concentração de 10 g/L foi selecionado para incorporação de fagos, e foi reticulado com CaCl2 com concentração de 10 g/L. A escolha deste foi baseada nas propriedades do filme como o grau de inchamento e a solubilidade. A atividade antimicrobiana dos filmes com fagos incorporados mostrou que o fago ΦIBBPF7A pode ser incorporado em filmes de alginato, mantendo a sua actividade após libertado levando a uma redução de 4 log para uma multiplicidade de infeção (MOI) de 10 em 24 h. Também foi possível confirmar que os fagos libertam-se para a carne levando a uma diminuição da contaminação pela bactéria Pseudomonas fluorescens. Os resultados mostram que os filmes de alginato com fagos incorporados pode ser usados no controlo do crescimento bacteriano em produtos cárneos, mostrando assim um potencial interesse para a indústria alimentar

Lactoferrin as a carrier of iron: Development and physicochemical characterization

Iron deficiency is the main cause of anemia, one of the most common nutritional deficiencies affecting millions of people worldwide. In addition, iron instability, sensitivity, and intense flavor limit its use in food fortification. In this work, lactoferrin (LF) particles were developed by Nano Spray Dryer (NSD) and its capacity to be used as an iron carrier was evaluated. The effect of NSD temperature (60°C, 80°C, and 100°C) and LF concentrations (10mgmL1, 50mgmL1, and 100mgmL1) was evaluated on the LF structure and on the production and stability of a LF-iron carrier. Results showed that the NSD is suitable for producing LF particles with diameters ranged from 38.8nm to 4533.6nm. Although different surface morphologies were obtained, higher protein concentrations (100mgmL1) produced round shape and smooth surface particles, but for lower protein concentrations (10mgmL1 and 50mgmL1) wrinkled particles and doughnut shape particles were obtained. SDS-page electrophoresis and circular dichroism (CD) for secondary structure (185260nm) show that the characteristics of the structures were maintained, meaning that NSD does not cause protein degradation. CD for tertiary structure (250nm350nm) and fluorescence tests confirmed the interaction between LF and iron, observed by an intensity decrease and a wavelength shift in fluorescence spectra. The CD tertiary structure analysis showed higher ellipticity for the Trp peak, meaning conformational changes in the neighbor amino acids due to protein-iron interaction. Iron release experiments were performed at different pH values (2.0 and 7.4) at 37°C aiming to understand the release mechanism in different media. Results showed that at pH 2 the iron release could be described by the linear superposition model (Radj2=0.9879) (explained by Fick and relaxation phenomenon) and that at pH 7.4 there is no iron release, showing that particles are stable at neutral pH. NSD is a suitable technology for producing iron-loaded protein-based carriers that could be used in food applications.INL -Idaho National Laboratory(2020.03447)info:eu-repo/semantics/publishedVersio

Analisando as pesquisas em educação especial no Brasil Analysing research in special education in Brazil

Nosso objetivo foi examinar a articulação lógica entre o problema e a proposição teórico-metodológica das produções na área da Educação Especial, focando os seus pressupostos epistemológicos. Nos fundamentamos nos pressupostos das tendências empírico-analítica, fenomenológica-hermenêutica, crítico-dialética e do paradigma da complexidade. O procedimento adotado foi interpretar todas as dissertações/teses produzidas nos Programas de Pós-Graduação em Educação e Educação Especial do Brasil, que versam sobre Educação Especial, produzidas nos anos de 2001, 2002 e 2003, disponíveis no banco de teses da CAPES. Encontramos as tendências empírica, fenomenológica e dialética. Os equívocos encontrados foram a não inserção da pesquisa entre as produções na área; ausência de criticidade; não posicionamento numa determinada concepção de educação; construção teórica fundamentada em concepções diferentes; falta de coerência nos pressupostos teórico-metodológicos; não explicitação metodológica; não descrição dos procedimentos éticos; e má elaboração dos resumos. Concluímos pela necessidade da melhoria das dissertações/teses para que possamos avançar na produção de conhecimento na área da Educação Especial.<br>Our objective was to analyze the logical articulation between the problem and the theoretical-methodological proposal of studies in the field of Special Education, focusing on the epistemological issues. We based our study on the empiric-analytical tendencies, phenomenology-hermeneutic, critical-dialectical and the complexity paradigm. The procedure that was adopted was interpreting all dissertations/thesis produced in Post-Graduate programs in Education and Special Education in Brazil, which focus on Special Education, produced in 2001, 2002 and 2003, available online at CAPES' thesis database. We found empirical, phenomenological and dialectic tendencies. The errors encountered included the failure to include the research among the productions in the field; lack of critical approach; lack of making explicit what educational conception the study was based on; theoretical construction based on different conceptions; lack of coherence in the theoretical-methodological proposals; lack of methodological specification; absence of ethical procedural descriptions; and poorly written abstracts. We came to the conclusion that improvements in theses /dissertations are necessary so as to continually move forward in the production of knowledge in the field of Special Education