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

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

New Trends in Natural Emulsifiers and Emulsion Technology for the Food Industry

The food industry depends on using different additives, which increases the search for effective natural or natural-derived solutions, to the detriment of the synthetic counterparts, a priority in a biobased and circular economy scenario. In this context, different natural emulsifiers are being studied to create a new generation of emulsion-based products. Among them, phospholipids, saponins, proteins, polysaccharides, biosurfactants (e.g., compounds derived from microbial fermentation), and organic-based solid particles (Pickering stabilizers) are being used or start to gather interest from the food industry. This chapter includes the basic theoretical fundamentals of emulsions technology, stabilization mechanisms, and stability. The preparation of oil-in-water (O/W) and water-in-oil (W/O) emulsions, the potential of double emulsions, and the re-emerging Pickering emulsions are discussed. Moreover, the most relevant natural-derived emulsifier families (e.g., origin, stabilization mechanism, and applications) focusing food applications are presented. The document is grounded in a bibliographic review mainly centered on the last 10-years, and bibliometric data was rationalized and used to better establish the hot topics in the proposed thematic

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

Optimization of microwave-assisted extraction of ergosterol from Agaricus bisporus L. by-products using response surface methodology

This work intends to valorise by-products of the industrial processing of mushrooms to obtain ergosterol as a value-added compound. Agaricus bisporus L. is the world’s most consumed mushroom and one of the richest sources of ergosterol. Microwave-assisted extraction was used to replace conventional techniques that are time-consuming and need large amounts of solvent. Time (3-20 min), temperature (60-210 ºC) and solid-liquid ratio (1-20 g/L) were found the relevant variables to analyze the extraction process. To maximize the ergosterol extraction yield, response surface methodology was used to optimize the process. The global optimal extraction conditions were determined and comprise: 19.4±2.9 min, 132.8±12.4 ºC and 1.6±0.5 g/L, yielding 556.1±26.2 mg of ergosterol per 100 g of mushroom by-products. In the MAE optimal conditions, it was possible to obtain ergosterol in a similar value to the one obtained in other works when using the Soxhlet extraction method with a significant decrease in the time of extraction. The results show the potential of using the by-products of an agroindustry, mushrooms processing industry, as productive sources of ergosterol.The authors acknowledge FCT (Portugal) for financial support to CIMO (PEst-OE/AGUI/0690/2014), Sandrina A. Heleno (SFRH/BPD/101413/2014) and L. Barros (SFRH/BPD/107855/2015), to FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (Project UID/EQU/50020/2013), and to QREN, ON2 and FEDER (Projects NORTE-07-0124-FEDER-000014 and NORTE-07-0162-FEDER-000050). The authors also acknowledge Xunta de Galicia for financial support of the post-doctoral researcher M.A. Prieto, and to Patrícia Diz for some support in MAE experiments