FCT2-Artigos (em revistas ou actas indexadas)
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- Enhancing cellulose and lignin fractionation from acacia wood: optimized parameters using a deep eutectic solvent system and solvent recoveryPublication . Magalhães, Solange; Aliaño González, María José; Rodrigues, Mariana; Fernandes, Catarina; Mendes, Cátia V. T.; Carvalho, Maria Graça V. S.; Alves, Luís; Medronho, Bruno; Rasteiro, Maria da GraçaCellulose and lignin, sourced from biomass, hold potential for innovative bioprocesses and biomaterials. However, traditional fractionation and purification methods often rely on harmful chemicals and high temperatures, making these processes both hazardous and costly. This study introduces a sustainable approach for fractionating acacia wood, focusing on both cellulose and lignin extraction using a deep eutectic solvent (DES) composed of choline chloride (ChCl) and levulinic acid (LA). A design of experiment was employed for the optimization of the most relevant fractionation parameters: time and temperature. In the case of the lignin, both parameters were found to be significant variables in the fractionation process (p-values of 0.0128 and 0.0319 for time and temperature, respectively), with a positive influence. Likewise, in the cellulose case, time and temperature also demonstrated a positive effect, with p-values of 0.0103 and 0.028, respectively. An optimization study was finally conducted to determine the maximum fractionation yield of lignin and cellulose. The optimized conditions were found to be 15% (w/v) of the wood sample in 1:3 ChCl:LA under a treatment temperature of 160 degrees C for 8 h. The developed method was validated through repeatability and intermediate precision studies, which yielded a coefficient of variation lower than 5%. The recovery and reuse of DES were successfully evaluated, revealing remarkable fractionation yields even after five cycles. This work demonstrates the feasibility of selectively extracting lignin and cellulose from woody biomass using a sustainable solvent, thus paving the way for valorization of invasive species biomass.
- Fortification of wheat white bread: assessing the suitability of beta vulgaris trough technological, nutritional, and sensory evaluationPublication . Issaoui, Manel; Oueslati, Samia; Flamini, Guido; Delgado, Amélia; Romano, AnabelaAs societies undergo shifts in dietary patterns, there is often an increase in nutrition-related issues. This is particularly evident in the case of wheat bakery products, which have evolved in an unsustainable way. The fortification of wheat flour with vegetables has emerged as a strategy to mitigate the imbalanced composition of white bread. The objective of this study is to address existing knowledge gaps regarding nutritional quality and technological characteristics of food-to-food fortified bakery products. A blend of Beta vulgaris powder (up to 5% of the total weight) was incorporated into commercial wheat white flour, and the resulting composition and technological parameters were analysed throughout the bread-making process, using standard methods (e.g., AAAC, ISO). The sensory assessment of the tested fortified baking products formulations was conducted. The 178 volunteer consumers noted the differences conveyed by B. vulgaris, but scored the taste and colour as acceptable (6 out of 9). Formulations containing moderate amounts of chard (e.g., 2%) were most appreciated. This study demonstrates that B. vulgaris can be employed to enrich white bread, particularly in minerals, such as calcium, magnesium, and iron, in a readily actionable manner that is well accepted by consumers. Furthermore, the use of flour blends contributes to mitigate the impact of fluctuations in wheat availability, thereby enhancing food security.
- Research and management of thermophilic cork forests in the central-south of the Iberian peninsulaPublication . Carmona, Eusebio Cano; Fuentes, José Carlos Piñar; Cano-Ortiz, Ana; Quinto Canas, Ricardo; Meireles, Catarina Rodríguez; Raposo, Mauro; Gomes, Carlos José Pinto; Spampinato, Giovanni; Musarella, Carmelo MariaThe investigated Iberian cork oak forests represent one of the ecosystems of greatest interest in the Iberian Peninsula, not only because of the ecosystem services they provide, but also because they are unique habitats in Europe and North Africa (habitat 9330). Due to the interest, they present, we carried out this study in order to obtain as exhaustive knowledge as possible, and to be able to offer environmental managers more information. We examined 12 cork oak associations in the Iberian Peninsula, both in their floristics, ecology and distribution as well as in terms of their dynamics, and we discovered that there are climaxes of Quercus Suber whose dynamics have not been established. We make a name correction because the name of the taxon used for the binomen Junipero badiaeQuercetum suberis Rivas-Martínez et al. 2002 nom corr, is not valid. We also propose the correction of the name of the association Cheirolopho sempervirentis-Quercetum suberis Pérez Latorre, Cabezudo in Pérez Latorre et al. 2008 nom. corr. The dynamics for the Cheirolopho sempervirentis-Quercetum suberis cork oak forest and the Cheirolopho sempervirentis-Arbutetum unedonis nova and Bupleuro gibraltarici-Quercetum suberis nova associations, and two plant communities are described. Based on the results obtained and the ICPN mandate, we propose to synonymize Oleo sylvestris-Quercetum suberis Rivas Goday, Galiano & Rivas-Martínez ex Rivas-Martínez 1987= (syn: Aro neglecti- Quercetum suberis Rivas-Martínez & Díez Garretas 2011).
- Global microplastic fiber pollution from domestic laundryPublication . Wang, Chunhui; Song, Jing; Nunes, Luís; Zhao, Hongting; Wang, Peng; Liang, Zhirong; Arp, Hans Peter H.; Li, Gang; Xing, BaoshanThe rapid expansion of fast fashion has significantly increased microplastic fiber (MPF) release during laundry practices, accounting for approximately one-third of primary microplastics entering the ocean. Currently, a significant gap exists in global-scale research on the release of MPFs from washing textiles. This study introduces an innovative empirical model to assess the spatial distribution of MPF emissions. The model estimates an annual global emission of 5.69 million tons of MPFs from laundry. Of this total, machine washing accounts for the majority (93.7 %), with hand washing contributing the remaining 6.3 %. As the primary source of MPF pollution, Asia's ' s emissions reach 3.71 million tons, far exceeding those of North America (1.18 million tons) and Europe (0.45 million tons). The primary issue is that wastewater management efficiency varies significantly worldwide. In Asia, there is persistently high discharge of MPFs into natural waters, and the removal efficiency of wastewater treatment plants is still comparatively low. In contrast, the United States and many European countries exhibit better MPF retention. The global nature of this challenge mandates international collaboration for comprehensive environmental conservation. Our study provides the first high-resolution global distribution map of MPF emissions and discharge into natural waters, establishing a data foundation for global and regional management of microplastics originating from household laundry sources.
- Effect of fruit thinning on fruit quality and alternate bearing of ‘Setubalense’ mandarin (Citrus deliciosa)Publication . Guerreiro, T.; Trindade, Ana Rita; Duarte, Amilcar; Matias, PedroCitriculture plays a major role in agriculture worldwide, especially in the Mediterranean region. However, there are limitations in citrus production. Alternate bearing can be a big problem when it is very intense. Trees produce a heavy yield one year (“on” year) and light ones the next (“off” year). During the “on” year, trees produce many small-sized fruits, while in the “off” year, they produce very few, larger fruits. The small size of the fruits is a limitation, as they are less well accepted in the market. The ‘Setubalense’ cultivar, a traditional Portuguese Mediterranean mandarin (Citrus deliciosa), is recognized for its excellent organoleptic characteristics. Despite this, the issues of alternate bearing and small fruit size are leading to the loss of this cultivar. Fruit thinning is a cultural practice involving the removal of some fruits, while leaving others. This practice can be used to manage alternate bearing and to improve fruit size. However, its impact on the plant is not well understood, whether it affects the plant as a whole or at a more localized level, such as within individual branches. To address this, two experiments were installed in August 2019. In the first experiment thinning involved removing 50% of the fruits from the entire tree. In this experiment, the fruit size and fruit quality were higher in the trees where fruit thinning was performed. In the second experiment, thinning was applied to selected branches, also removing 50% of the fruits. In this case, no significant differences were observed, neither in fruit size nor in fruit quality. Furthermore, fruit thinning did not reduce alternate bearing in either experiment.
- Teaching the rate-and-state friction law using interactive computational modellingPublication . Neves, Maria; Neves, Rui GomesA learning sequence with interactive computational modelling based on Modellus designed for introductory seismology university courses is discussed. The sequence considers earthquake generation mechanics and applies Modellus to determine the evolution of the friction coefficient as given by the rate-and-state friction law governing the frictional instabilities that give rise to earthquakes. Laboratory experiments indicate that the rate-and-state friction law applies not only to rocks but also to some metals, paper, wood, and some plastics. The use of Modellus allows for a parametric study of the equations and for students to create the mathematical models on their own, which ultimately helps them achieve a better understanding of the complex earthquake phenomena.
- Stacking self-gluing cellulose II films: a facile strategy for the formation of novel all-cellulose laminatesPublication . Dahlström, Christina; Duan, Ran; Eivazi, Alireza; Magalhães, Solange; Alves, Luís; Engholm, Magnus; Svanedal, Ida; Håkan Edlund; Medronho, Bruno; Norgren, MagnusCellulose laminates represent a remarkable convergence of natural materials and modern engineering, offering a wide range of versatile applications in sustainable packaging, construction, and advanced materials. In this study, novel all-cellulose laminates are developed using an environmentally friendly approach, where freshly regenerated cellulose II films are stacked without the need for solvents (for impregnation and/or partial dissolution), chemical modifications, or resins. The structural and mechanical properties of these all-cellulose laminates were thoroughly investigated. This simple and scalable procedure results in transparent laminates with exceptional mechanical properties comparable to or even superior to common plastics, with E-modulus higher than 9 GPa for a single layer and 7 GPa for the laminates. These laminates are malleable and can be easily patterned. Depending on the number of layers, they can be thin and flexible (with just one layer) or thick and rigid (with three layers). Laminates were also doped with 10 wt% undissolved fibers without compromising their characteristics. These innovative all-cellulose laminates present a robust, eco-friendly alternative to traditional synthetic materials, thus bridging the gap between environmental responsibility and high-performance functionality.
- Environmental factors related to climate change alter the chemical composition and biological activity of lavandula viridis l’Hér essential oilPublication . Paixão Mansinhos, Inês Filipa; Gonçalves, Sandra; Rodríguez Solana, Raquel; Moreno-Rojas, José Manuel; Romano, AnabelaClimate change is affecting all regions of the world, and the Mediterranean region is one of the most affected. Plants accumulate secondary metabolites as an adaptive response to stress circumstances. The present study investigated the effect of different abiotic factor conditions (drought, moderate heat, severe heat, salinity, and UV-B radiation) on the essential oil (EO) yield, composition (volatile profile), and biological activity (enzyme inhibition and antioxidant activity) of Lavandula viridis L'Her. In general, the environmental conditions increased the extraction yield of EO. Eighty-two compounds were identified in the EO and environmental factors induced some quantitative changes in EO composition. Severe heat and salinity conditions increased the concentration of the two most abundant compounds, 1,8-cineole and camphor. Severe heat also increased the potential of EO to inhibit the enzymes butyrylcholinesterase and tyrosinase. Drought, salinity, and UV-B radiation promoted the ability of EO to inhibit acetylcholinesterase. In addition, heat and drought enhanced the antioxidant activity of EO. These results are relevant for exploring the potential of this EO for industrial applications, although future studies combining the factors studied are important to understand the influence of synergistic effects on the composition and bioactivity of the plant products obtained.
- How climate change-related abiotic factors affect the production of industrial valuable compounds in lamiaceae plant species: a reviewPublication . Paixão Mansinhos, Inês Filipa; Gonçalves, Sandra; Romano, AnabelaThe interest in medicinal and aromatic plants (MAPs) has increased significantly in recent years, driven by the growing demand for natural products. MAPs are a valuable source of secondary metabolites, which renders them useful to a number of industries, including cosmetics, pharmaceuticals, and food. The Lamiaceae family includes economically important MAPs that produce valuable secondary metabolites such as essential oils (EOs) and phenolic compounds (PCs). The quantity and quality of these secondary metabolites are affected by abiotic stress factors. In a climate change scenario, the Lamiaceae is one of the most affected families, especially due to its wide distribution in the Mediterranean region. In the present study, the most common climate-related environmental stress factors, namely, drought, salinity, temperature, light, and heavy metals, were reviewed and discussed in order to assess their impact on the chemical profiles of EOs and PCs, as well as on the biological properties (antioxidant, antibacterial, antimelanogenic, pest-repellent, and UV-protective) of Lamiaceae species. It can be posited that these stresses typically act as a catalyst for the secondary metabolism of these plants, resulting in increased production of EO compounds (e.g., 1,8-cineole, linalool, camphor, borneol, and limonene) and PCs (e.g., rosmarinic, caffeic, and salvianolic acids) and subsequent enhancement of their biological activities. In view of the industrial applications of these bioactive compounds, it is of interest to explore the changes in secondary metabolism induced by environmental factors as it is possible to increase the accumulation of valuable secondary metabolites.
- Camptothecin-loaded mesoporous silica nanoparticles functionalized with CpG oligodeoxynucleotide as a new approach for skin cancer treatmentPublication . Qureshi, Munibah; Viegas, Cláudia; Duarte, Sofia O.D.; Girardi, Michael; Shehzad, Adeeb; Fonte, PedroThe therapeutic efficacy of camptothecin (CPT), a potent antitumor alkaloid, is hindered by its hydrophobic nature and instability, limiting its clinical use in treating cutaneous squamous cell carcinoma (SCC). This study introduces a novel nano drug delivery system (NDDS) utilizing functionalized mesoporous silica nanoparticles (FMSNs) for efficient CPT delivery. The FMSNs were loaded with CPT and subsequently coated with chitosan (CS) for enhanced stability and bioadhesion. Importantly, CpG oligodeoxynucleotide (CpG ODN) was attached onto the CS-coated FMSNs to leverage the immunostimulatory properties of CpG ODN, augmenting the chemotherapy's efficacy. The final formulation FMSN-CPT-CS-CpG displayed an average size of 241 nm and PDI of 0.316 with an encapsulation efficiency of 95 %. Comprehensive in vitro and in vivo analyses, including B16F10 cells and DMBA/TPA-induced SCC murine model, demonstrated that the FMSN-CPT-CS-CpG formulation significantly enhanced cytotoxicity against B16F10 cells and induced complete regression in 40 % of the in vivo subjects, surpassing the efficacy of standard CPT and FMSN-CPT treatments. This study highlights the potential of combining chemotherapeutic and immunotherapeutic agents in an NDDS for targeted, efficient skin cancer treatment.