Browsing by Issue Date, starting with "2023"
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- Biosynthesis of antioxidant xanthan gum by Xanthomonas campestris using substrates added with moist olive pomacePublication . Crugeira, Pedro Jorge Louro; Almeida, Heloísa H.S.; Marcet, Ismael; Rendueles, Manuel; Pires, Marcella Golini; Rafael, Helder Martins; Rodrigues, Ana Isabel G.; Santamaria-Echart, Arantzazu; Rafael, Helder; Barreiro, M.F.; Golini Pires, MarcellaMoist olive pomace (MOP) is a high moisture content by-product of the olive oil industry. Managing this recalcitrant residue (transport, storage, and drying) is a priority demanding investment in finding alternative valorisation routes. In this context, the biosynthesis of xanthan gum (XG) incorporating MOP in the substrate (0.0 %, 5.0 %, 10.0 %, 15.0 %, 20.0 %, 25.0 %, 30.0 % and 50.0 %) to induce bacterial stress was attempted. XG biosynthesis yield was quantified, and the product was characterised by structural analysis (FTIR), thermal behaviour (TG), rheology and antioxidant capacity. Relative to the control (sample with no added MOP), a significant increase in XG biosynthesis was found for concentrations up to 30.0 % MOP. In particular, for XG produced with 15 % MOP, a 50.91 % (p < 0.0001) increase was achieved, together with 395.78 % for viscosity. In general, XG produced with MOP presence showed antioxidant activity, a value-added property, especially for applications in the food, pharmaceutical and cosmetic areas. The results indicated that the stress imposed by the MOP induced a microbial response leading to XG production increase, structural and viscosity modifications, and antioxidant properties incorporation. Overall, this work points out a new MOP application contributing to the sustainability of the olive oil productive chain from a biobased circular economy perspective.
- Biochar in carbon sequestrationPublication . Shirzad, Mohammad; Karimi, Mohsen; Rodrigues, Alírio; Silva, José A.C.The increase of carbon dioxide emissions and the global warming consequences is today a considerable environmental concern. On the contrary, the rapid growth in the energy consumption throughout the world has exacerbated the CO2 emissions to the atmosphere. Accordingly, carbon capture sequestration and utilization have been considered as a potential emission mitigation strategy. In this way, several strategies and technologies including: absorption, membranes, adsorption etc. have been proposed, which adsorption technology using solid sorbents due to the lower environmental side-effects also lower energy consumption is one of the most favorable strategies. However, despite the significant efforts made for developing novel solid adsorbents for CO2 mitigation, still the elements of cost and synthesis have remained as main challenges. To this end, biochar carbon materials have been employed as a source of adsorbent through CO2 capture and sequestration process not only to satisfy these factors but also as a pathway to the solid waste management. Herein, the key concepts on the carbon capture and sequestration also adsorption processes have been discussed. Next, the capability of biomass/biochar as a low-cost origin of potential adsorbent is extensively discussed.
- Carbon dioxide separation and capture by adsorption: a reviewPublication . Karimi, Mohsen; Shirzad, Mohammad; Silva, José A.C.; Rodrigues, AlírioRising adverse impact of climate change caused by anthropogenic activities is calling for advanced methods to reduce carbon dioxide emissions. Here, we review adsorption technologies for carbon dioxide capture with focus on materials, techniques, and processes, additive manufacturing, direct air capture, machine learning, life cycle assessment, commercialization and scale-up.
- The transformation of the silvopastoral landscape of Montesinho Natural Park (1995 – 2021)Publication . Seripieri, Vitor Henrique Mistro; Castro, José; Silva, Maria Madalena; Castro, Marina; Seripieri, Vitor Henrique MistroIn the grazing areas of the Montesinho Natural Park (PNM), the diet of small ruminants is shaped by the available landscape, through the daily routes chosen by the shepherd to feed his flock. Thus, in addition to grazing, sheep and goats benefit from a combination of agricultural by-products and spontaneous vegetation, such as stubble fields, chestnut and olive groves, leftovers and pruning, as well as forests and scrubland. Changes in land use inevitably lead to adaptations in pastoral routes. An analysis of the evolution of the landscape explains the changes in the various land uses that make up the landscape, whether natural, semi-natural or anthropic, and which have been determined by global changes, in particular climate change. This study updated PNM's Natural and Semi-Natural Vegetation Map (1995), an analogue cartography of great historical value that was transferred to digital format, requiring a refinement of its geometry and classification to ensure that the results were not affected by the different methodologies inherent in its creation. To achieve this, we chose to adapt the polygons of the original cartography to the currently available land structure geometry, namely the ISIP geographical database, and to update it based on images from 2021, complemented by field visits and visual interpretation of other images from different seasons and dates. The data were processed in a GIS environment, using the QGIS tool, which allowed the interpretation of the landscape transformation in the last 26 years, quantified by a transition matrix, and the trend for the next 26 years. From the results we can conclude that there has been a drastic decrease in the areas of extensive and intensive dry farming (-47%), while an increase perennial plantation (olive and chestnut groves) (+38%) has been observed, with some peculiarities. The other categories remained constant and are expected to continue to increase, albeit at a slower rate.
- Caraterização química e biológica de lamas de Estações de Tratamento de Águas Residuais (ETAR´s)Publication . Gusmão, Andressa Griebler; Gusmão, Andressa Griebler; Arrobas, Margarida; Pereira, Ermelinda; França, Michelle MilanezO crescimento industrial e demográfico acarretou em um aumento significativo na produção global de resíduos, especialmente no que diz respeito às águas residuais urbanas. O estudo teve como objetivo a caraterização de lamas de diferentes ETAR ́s, no seu estado original e tratadas com hidróxido de cálcio e óxido de cálcio em várias dosagens, visando sua utilização agrícola (10, 20, 30, 40 e 50% de CaO e Ca(OH)2, massa por massa). As lamas foram sujeitas a análises previstas no Decreto-Lei 276/2009. As concentrações de nutrientes variaram significativamente entre as ETAR ́s. Os teores de C (g kg-1) revelaram que Bragança apresentou a maior concentração, 515,40 g kg-1, enquanto Ponte de Baia apresentou somente 235,66 g kg-1. O teor mais elevado em N (g kg-1) foi registado em Gelfa (69,60 g kg-1) e o menor em Viana do Castelo (45,48 g kg-1). A relação C:N apresentou o maior valor na ETAR de Bragança (11,6), ainda assim mostrando um elevado potencial de mineralização. Os teores de P indicaram que o valor mais elevado foi em Ponte de Baia (23,0 g. kg-1) e menor em Bragança (5,77 g kg-1). A adição de cal não afetou os teores de potássio e magnésio. Por outro lado, para cálcio, à medida que foi sendo adicionado a cal (CaO ou Ca(OH)2), sua concentração foi aumentando, sendo o valor mais alto encontrado no tratamento com hidróxido de cálcio 50% em Paço de Sousa (203,16 g kg-1). Em contraponto, e em geral, amostras sem tratamento foram as que tiveram maiores concentrações de outros nutrientes, incluindo o boro. Este elemento apresentou a maior concentração em Ponte de Baia (47,7 mg kg-1). Os resultados microbiológicos mostraram que as lamas tratadas a partir de 20% de óxido de cálcio foram eficazes na eliminação de patogénicos, como E. coli e Salmonella spp. Através da Ánalise de Componentes Principais (ACP) os metais pesados apresentaram uma correlação inversa com o crescimento de microrganismos patogénicos, aparecendo o níquel como o principal inibidor. Além disso, a adição de cal acima de 40% causou desequilíbrios entre os íons de cálcio e os íons metálicos nas ETAR ́s de Gelfa e Ponte de Baia, afetando a imobilização de metais pesados. Apesar disso, todas as lamas analisadas no estudo tiveram seus respetivos limites de metais abaixo dos critérios estabelecidos pela legislação portuguesa. No entanto, se torna necessário o monitoramento e caraterização contínua dos dados, visando a proteção do meio ambiente, da saúde humana e animal.
- A transformação da paisagem pastoril no Parque Natural Montesinho (1995 – 2022)Publication . Seripieri, Vitor Henrique Mistro; Seripieri, Vitor Henrique Mistro; Castro, José; Silva, Maria Madalena Santos daAnalisar a transformação dos usos agrícolas e florestais de um território é uma das abordagens mais utilizadas para compreender o efeito de fatores, tais como as mudanças climáticas e as antrópicas, na evolução de uma paisagem. Sabendo disso, este trabalho avalia a evolução da paisagem pastoril do Parque Natural de Montesinho, por meio da interpretação de registos aerofotográficos do local estudado em datas diferentes, com o objetivo de quantificar as principais alterações no uso e ocupação das zonas de pastoreio de 1995 a 2021. O trabalho foi dividido em 2 etapas. A primeira consistiu no reajuste do Mapa de Vegetação Natural e Seminatural do PNM (1995) à geometria atualmente disponível da estrutura fundiária, nomeadamente a base de dados geográficos do Sistema de identificação parcelar (iSIP) conhecida como “parcelário”, apoiado em ortofotos de 1995. Essa etapa teve o intuito de corrigir e ajustar a geometria dos diferentes usos e ocupações do terreno. A segunda etapa foi realizada para atualizar a mesma cartografia, apoiados agora em uma ortofotoorto fotos de 2021 da mesma área observada na etapa anterior, a fim de obter a evolução do uso e ocupação do território ao longo desses 26 anos. Os resultados foram confirmados com visitas a campo e interpretações de imagens do Google Earth Pro, em diferentes estações do ano. Os resultados permitiram a criação de uma matriz de transição entre essas datas, possibilitando interpretar a tendência dessas transformações, e extrapolar para igual período futuro (2047). As principais transformações observadas na matriz agrícola foram as substituições dos sequeiros (- 53%) pela implantação de agricultura perene, como castanheiro (41%) e oliveira (3%). Na matriz florestal, houve um aumento dos carvalhais (18%) e giestais (30%), decorrente do abandono populacional da região estudada. Caso seja esta a tendência da transformação nos próximos 26 anos, tal exigirá da gestão do PNM, atitudes protetivas tanto em relação à paisagem e à população quanto aos investimentos na matriz agrícola, nomeadamente no que diz respeito ao risco de incêndios potenciado pelos fenómenos extremos associados à mudança climática.
- Real-time indoor air quality (IAQ) monitoring system for smart buildingsPublication . Biondo, Elias Junior; Lima, José; Brito, Thadeu; Nakano, Alberto YoshihiroIndoor air quality (IAQ) is a term describing the air quality of a room, it refers to the health and comfort of the occupants. Normally, people spend around 90% of their time in indoor environments where the concentration of air pollutants, such CO, CO2, VOCs, SO2, O3 and NOx, may be two to five times — and occasionally, more than 100 times — higher than outdoor levels. According to the World Health Organization (WHO), the indoor air pollution is responsible for the deaths of 3.8 million people annually. It has been indicated that IAQ in residential areas or buildings is significantly affected by three primary factors: (i) Outdoor air quality, (ii) human activity in buildings, and (iii) building and construction materials, equipment, and furniture. In this contest, this work consist in a real time IAQ system to monitoring and control thermal comfort and gas concentration. The system has a data acquisition stage, where the data is measured by a set of sensors and then stored on InfluxDB database and displayed in Grafana. To track the behavior of the measured parameters, two machine learning algorithms are developed, a mathematical model linear regression, and an artificial intelligence model neural network. In a test made to see how precise were the prediction of the two models, linear regression model performed better then neural network, presenting cases of up to 99.7% and 98.1% of score prediction, respectively. After that, a test with smoke was done to validate the models where the results shows that both learning models can detect adverse cases. Finally, prediction data are storage on InfluxDB and displayed on Grafana to monitoring in real-time measured data and prediction data.
- Upcycling fish by-products into bioactive fish oil: the suitability of microwave-assisted extractionPublication . Pinela, José; Rodrigues, Matilde; Pires, Tânia C.S.P.; Mandim, Filipa; Almeida, André; Dias, Maria Inês; Caleja, Cristina; Barros, LillianThe seafood industry is often left out of the food waste discussion, but this sector is no exception, as it generates large amounts of various by-products. This study aimed to explore the potential of the microwave-assisted extraction (MAE) technique to obtain high-quality oil from fish by-products. The independent variables, which were time (1-30 min), microwave power (50-1000 W), and solid/liquid ratio (70-120 g/L) were combined in a 20-run experimental design coupled with the response surface methodology (RSM) for process optimization. The obtained oil yield values were fitted to a quadratic equation to build the theoretical models, which were statistically validated based on statistical criteria and used to predict the optimal MAE condition. The oil yields were significantly affected by the three independent variables through linear, quadratic, and/or interactive effects. Compared to a conventional Soxhlet extraction (SE), the optimal MAE conditions allowed between 60 and 100% of oil to be recovered in less than 19 min and with less solvent consumption. The fatty acid profiles of the oils obtained through SE and optimized MAE were characterized by gas chromatography with flame ionizing detection (GC-FID) after a derivatization process. These oils were constituted mainly of health, beneficial unsaturated fatty acids, such as oleic, docosahexaenoic (DHA), linoleic, and eicosapentaenoic (EPA) acids, which were not affected (p > 0.05) by the extraction methods. Interestingly, the oils obtained through MAE showed the best microbial growth inhibition results may have been due to thermolabile compounds, preserved via this unconventional non-thermal method. The oils also exhibited anti-inflammatory effects via nitric oxide production inhibition and cytotoxic potential especially, against breast and gastric adenocarcinoma cells. However, the threshold of toxicity should be further investigated. Overall, this work emerges as a future-oriented approach to upcycling fish by-products into high-quality oils that can be used in the formulation of pet food and other products.
- Chemical and bioactive characterization of blueberry bioresiduesPublication . Plasência, Paula; Heleno, S.A.; Garcia, Pablo; Barreiro, Filomena; Ferreira, Isabel C.F.R.; Barros, LillianBlueberry production has increased exponentially in recent decades due to its known high nutritional characteristics, and bioresidues originating from its culture have also increased. It is critical to limit its buildup. One strategy for directing these residues is to turn them into high-value products while investigating their potential bioactivity. The goal of this study was to produce bioactive extracts from blueberry aerial parts using environmentally friendly methods. Different extracts, such as infusion, maceration, and decoction, were considered, as well as emerging extraction technologies, such as ultrasound-assisted extraction, in which different conditions (potency, temperature, and solvent type) were tested to achieve optimal extraction conditions (high yields and purity). The obtained extracts were studied regarding their chemical profile through phenolic compound´s identification and quantification by HPLC-DAD-MS.
- Ethosomes: an approach for bioactive plant extract preservation envisaging cosmetic applicationsPublication . Plasencia, Paula; Santamaria-Echart, Arantzazu; Heleno, S.A.; Colucci, Giovana; Garcia, Pablo; Barros, Lillian; Barreiro, FilomenaThe present work is focused on upgrading the commercial potential of berry crop by-products by encapsulating them into liposomes to preserve their bioactivity. The extracts have been obtained with an ethanol-water mixture using ultrasound-assisted extraction, and the most promising ones were encapsulated in ethosome system. To achieve this goal, ethosomes were prepared using the cold method. Ethosomal suspensions were characterized concerning particle size distribution by laser dispersion, differential scanning calorimetry, infrared Fourier-transform spectroscopy, encapsulation efficiency, and morphological analysis using optical, scanning electron, and transmission electron microscopy. These results indicate that ethosomes are an appropriate method to encapsulate hydroethanolic bioactive plant bioresidue extracts and a good option to preserve them for further use in industrial applications, such as cosmetics. Future work will include optimizing the process and proof of concept by developing a cosmetic application.