57 research outputs found
From berry plant cropping to a cosmetic formula: sustainable upcycling of active ingredients
Due to the interest in berry fruit's antioxidant properties, its worldwide production has been increasing in the past two decades, as has its waste. Bioresidues produced by the agri-food industry are increasingly intrinsic to the world’s economy, and researchers are looking for new ways to enhance their use. Innovations are being developed to transform these residues into high-value raw materials with industrial applications, promoting the circular economy concept. Bioactive extracts from blueberry and raspberry aerial parts using green methodologies were obtained for this work. Different extraction techniques were considered and different conditions were tested to achieve optimal extraction conditions.info:eu-repo/semantics/publishedVersio
Chemical and bioactive characterization of blueberry bioresidues
Blueberry 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.info:eu-repo/semantics/publishedVersio
Advances in Waterborne Polyurethane and Polyurethane-Urea Dispersions and Their Eco-friendly Derivatives: A Review
Polyurethanes and polyurethane-ureas, particularly their water-based dispersions, have gained relevance as an extremely versatile area based on environmentally friendly approaches. The evolution of their synthesis methods, and the nature of the reactants (or compounds involved in the process) towards increasingly sustainable pathways, has positioned these dispersions as a relevant and essential product for diverse application frameworks. Therefore, in this work, it is intended to show the progress in the field of polyurethane and polyurethane-urea dispersions over decades, since their initial synthesis approaches. Thus, the review covers from the basic concepts of polyurethane chemistry to the evolution of the dispersion’s preparation strategies. Moreover, an analysis of the recent trends of using renewable reactants and enhanced green strategies, including the current legislation, directed to limit the toxicity and potentiate the sustainability of dispersions, is described. The review also highlights the strengths of the dispersions added with diverse renewable additives, namely, cellulose, starch or chitosan, providing some noteworthy results. Similarly, dispersion’s potential to be processed by diverse methods is shown, evidencing, with different examples, their suitability in a variety of scenarios, outstanding their versatility even for high requirement applications.This research was funded by the University of the Basque Country (UPV/EHU) (GIU18/216 Research Group), the Spanish Ministry of Science, Innovation and Universities and European Union (MICINN/EU/FEDER) (MAT2016-76294-R and PID2019-105090RB-I00). Also, the Foundation for Science and Technology (FCT, Portugal) funded by financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020). National funding by FCT- Foundation for Science and Technology, through the institutional scientific employment program-contract with I.F. Valor Natural project for the contract of A.S.-E. (Mobilizer Project Norte-01-0247-FEDER-024479)
Fire performance of wood and wood-based panels towards the development of wood fire doors
Fires in buildings continue to be responsible for high human and economic losses. The increasing demand for legal requirements in the fire safety sector has been complemented by performance criteria of construction products, increasing the requirements of their essential technical characteristics, such as thermal, acoustic, and fire behaviour, as prescribed in the European Construction Products Regulation (CPR).
This work addresses the development of an innovative system for the production of wood fire doors based on solid wood, wood-based panels, and lightweight materials with enhanced fire performance, aiming at improving the integrity and insulation (EI) fire resistance time.
For this purpose, the fire behaviour of different solid woods and wood-based panels were analysed in a cone calorimeter, under the action of a 75 [kW/m2] radiative heat flux. The study considers pine wood (Pinus pinaster), tulip tree wood (Liriodendron tulipifera), plywood panels, and Medium-Density Fibreboard (MDF) of different thicknesses. During each test, the heat release rate, total heat release, and sample mass loss were measured and evaluated for comparison. Using a set of thermocouples type k placed on the exposed face and non-exposed faces, and in the sample interior at different depths, the temperature evolution was measured over time, allowing to determine the through-thickness heating rate.
Results show a mass loss rate that changes with the MDF thickness, resulting in a reduction of 50% mass loss after 3.73 [min] and 11.57 [min] exposure, for 10 [mm] and 22 [mm] boards, respectively. Similarly, the peak heat release rate is higher for thinner boards. Plywood boards have higher heat release rates compared to MDF boards, with the same thickness, due to the resin used between each layer. For the same exposure time, the pine wood samples release more heat compared to the tulip wood, having the latter a higher mass loss rate.
The temperature distribution measured across the thickness allowed the estimation of the charring rate and evaluate the insulation performance of each sample.info:eu-repo/semantics/publishedVersio
Thermomechanical behaviour of bonded joints of wood and wood-based panels at room and elevated temperatures
Wood is a natural material traditionally used in the construction industry. In recent decades, developments in
scientific research have turned wood into a high-tech construction material. Increased interest in bonded joints in wood construction is due to the advantages of adhesive technology compared to traditional mechanical joining techniques. It is very important to understand the influence of elevated temperatures on adhesives due to their use in multilayer systems such as compartmentation walls and fire-resistant doors, which require adequate mechanical and thermal resistance in fire situations. The purpose of this study is to investigate the mechanical behaviour of different structural adhesives on bonded connections of wood and wood-based panels at room and elevated temperatures through experimental testing. The performance of the adhesives was evaluated at room temperature and at 50 °C, 100 °C, 150 °C, and 200 °C.info:eu-repo/semantics/publishedVersio
Saponin-based natural nanoemulsions as alpha-tocopherol delivery systems for dermal applications
Nanoemulsions can be produced using simple methods and compounds from natural sources. They can increase water dispersibility and bioavailability and optimise active ingredient dispersion in particular skin layers. Lipophilic compounds of the vitamin E family (tocopherols and tocotrienols) are well-known for their high antioxidant activity and capacity to protect the skin from oxidative stress. In this context, oil-in-water (o/w) nanoemulsions with and without α-tocopherol (Vitamin E, VE) were formulated with two emulsifier alternatives, Quillaja saponin (QS), and a combination of QS with Tribulus terrestris (QSTT) (50/50, w/w). The emulsions were evaluated concerning stability, microstructure, droplet size, colour attributes, encapsulation efficiency, UV photostability, antioxidant activity, and in vitro permeation studies to assess the delivery potential. Results showed highly stable systems, with round-shape droplets of 80–121 nm size. QS and QSTT samples' colours were close to white and light brownish, respectively. The topical nano cream had the capacity to entrap VE, producing a protective effect from UV degradation, and very significant antioxidant activity, with IC50 values around 0.01 %wt. The skin permeation profiles showed the efficiency of the formulations in the delivery of VE, with permeabilities between 64 and 74 µg/cm2, while the control sample showed no VE permeation.info:eu-repo/semantics/publishedVersio
In vitro digestion and bioaccessibility studies of vitamin E-loaded nanohydroxyapatite pickering emulsions and derived fortified foods
Vitamin E is a lipophilic vitamin playing an essential role in human health. Due to oxidative instability, it presents fast degradation and bioactivity loss. In this study, vitamin E-loaded Pickering emulsions stabilized by nano-hydroxyapatite (n-HAp) were produced using a static mixer (NETmix), a technique enabling continuous production and droplet size tailoring. Thus, oil-in-water (O/W) emulsions containing vitamin E at a content of 1mg/mL were produced with different droplet sizes (7.53, 11.56 and 17.72m) using an O/W ratio of 20/80 (v/v). Their stability during in vitro gastrointestinal digestion and vitamin E bioaccessibility were investigated. It was observed that n-HAp particles disrupt in the stomach and subsequently aggregate as random calcium phosphates in the small intestine, leading to low vitamin E bioaccessibility due to oil entrapment. The emulsion showing the highest vitamin E bioaccessibility (3.29±0.57%, sample with the larger average droplet size) was used to produce fortified gelatine and milk, resulting in an increased bioaccessibility (10.87±1.04% and 18.07±2.90%, respectively). This fact was associated with the presence of macronutrients and the lower n-HAp content. Overall, n-HAp Pickering emulsions offer advantages for vitamin E encapsulation directed to fortified foods development, a process able to be extended to other lipophilic vitamins.This work was financially supported by Base Funding -UIDB/50020/2020 of the Associate Laboratory LSRE-LCM -funded by national funds through FCT/MCTES (PIDDAC), Base Funding -UIDB/00690/2020 of CIMO -funded by national funds through FCT/MCTES (PIDDAC), and Base Funding -UIDB/04469/2020 of the CEB funded by national funds through FCT. Andreia Ribeiro acknowledges her PhD fellowship funded by Project NORTE-08-5369-FSE-000028, supported by N2020, under PT2020, through ESF, and Raquel F. Goncalves acknowledges the Foundation for Science and Technology (FCT) for their fellowship (SFRH/BD/140182/2018). Authors thank Fluidinova S.A. for providing samples of nanoXIM-CarePaste and Instituto de Investigacao e Inovacao em Saude (i3S) for the services provided with CLSM analysis.info:eu-repo/semantics/publishedVersio
Water-based polyurethane dispersions: Chemistry, Technology and applications
Over the past few decades, polyurethane-polyurea aqueous dispersions (PUDs) have developeda solid reputation for high performance applications, particularly in the field of adhesives andcoatings. PUDs are mostly environmentally compatible products; they are totally devoid orcontain only low amounts of volatile organic compounds(VOC). This is an important feature inview of the present environmental policies where governments and internal agencies are placingemphasis on developing sustainable processes, improving work conditions and reducingemissions of toxic and pollutingsubstances into the atmosphere.In the past years, our research group has beeninvolved in the development of polyurethane-polyurea aqueous dispersions for two main applications (footwear and indirect food contact).With this work we intend to review this themeand describe some of the achieved developments.Characterization of commertial dispersions will be presented and examples of synthesis will bedescribed, following a modified pre-polymer process developded in our group
Recovery of high valuable bioactive molecules from Vaccinium myrtillus L. bioresidues
Purpose The interest in using bioresidues produced by the agri-food industry is increasingly intrinsic to the world economy.
As such, researchers started to look for new ways to enhance its use, developing innovations to transform these residues into
high-value raw materials with industrial application, promoting the circular economy concept.
Methods Therefore, pruning residues from the production of Vaccinium myrtillus L. could be an interesting exploitation
feld, given its position as a superfood due to its well-known antioxidant properties. The antioxidant, antibacterial, anti infammatory, anti-tyrosinase, and cytotoxicity potentials of aqueous and hydroethanolic extracts of V. myrtillus aerial parts
were evaluated.
Results From the obtained results, ultrasound-assisted and maceration extracts were found to be as efective as, if not more
efective than, conventional antibiotics against methicillin-resistant Staphylococcus aureus. Aside from antibacterial activ ity, the extracts also showed antioxidant and anti-tyrosinase efects, which were found to be favourably related to the level
of cafeoylquinic acid derivatives.
Conclusion The obtained results highlight the bioactive potential and the importance of exploiting this bio residue as a novel
candidate for industrial application, taking advantage of their biological properties.
Graphical AbstractFoundation for Science and Technology (FCT,
Portugal) for financial support through national funds FCT/MCTES
to CIMO (UIDB/00690/2020); the contract of L. Barros through the
institutional scientific employment program-contract, the contracts of
M. Carocho and S.A. Heleno (CEEC-IND/00831/2018 and CEECIND/
03040/2017) through the individual scientific employment program-
contract, and the PhD studentship granted to M. Añibarro-Ortega
(2020.06297.BD). To the “La Caixa” Foundation and to FCT for the
financial support through Project “Aquae Vitae — Thermal water as a
source of life and health”, Promove Mobilizer programme. This work
is also supported by MICINN for the Juan de la Cierva Formación
contract for T. Oludemi (FJC2019-042549-I).info:eu-repo/semantics/publishedVersio
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