Percorrer por autor "Barreiro, M.F."
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- Adding molecules to food, pros and cons – A review on synthetic and natural food additivesPublication . Carocho, Márcio; Barreiro, M.F.; Morales, Patricia; Ferreira, Isabel C.F.R.The pressing issue to feed the increasing world population has created a demand to enhance food production, which has to be cheaper, but at the same time must meet high quality standards. Taste, appearance, texture, and microbiological safety are required to be preserved within a foodstuff for the longest period of time. Although considerable improvements have been achieved in terms of food additives, some are still enveloped in controversy. The lack of uniformity in worldwide laws regarding additives, along with conflicting results of many studies help foster this controversy. In this report the most important preservatives, nutritional additives, coloring, flavoring, texturizing, and miscellaneous agents are analyzed in terms of safety and toxicity. Natural additives and extracts, which are gaining interest due to changes in consumer habits are also evaluated in terms of their benefits to health and combined effects. Technologies, like edible coatings and films which have helped overcome some drawbacks of additives, but still pose some disadvantages, are briefly addressed. Future trends like nanoencapsulation and the development of “smart” additives and packages, specific vaccines for intolerance to additives, use of fungi to produce additives, and DNA recombinant technologies are summarized.
- Advancements in conventional and supercritical CO2 extraction of Moringa oleifera bioactives for cosmetic applications: A reviewPublication . Kessler, Júlia C.; Martins, Isabel M.; Manrique, Yaidelin A.; Rodrigues, Alírio; Barreiro, M.F.; Dias, Madalena M.Moringa oleifera L. extracts (Mo) have attracted attention as a sustainable and effective alternative to synthetic ingredients for cosmetic formulations. The unique and diverse phytochemical profile of the Mo tree enhances the quality and appeal of commercial products, as evidenced by numerous studies and patents. Supercritical carbon dioxide extraction (SFE-CO2) is particularly advantageous for this purpose, offering enhanced thermostability and selectivity of extracted compounds compared to conventional methods. This review examines the safety and efficacy of Mo seed, leaf, and root extracts as cosmetic ingredients, focusing on their bioavailability and performance by considering the thermodynamics and operational benefits of SFE-CO2. The collected data highlights the method’s efficiency in terms of the total extraction yield and the recovery of target compounds from Mo, providing insights from optimisation studies and linking the solvation power of supercritical CO2 with the significant non-polar and low-polar compounds present in Mo extracts.
- Advances in waterborne polyurethane and polyurethane-urea dispersions and their eco-friendly derivatives: a reviewPublication . Santamaria-Echart, Arantzazu; Fernandes, Isabel P.; Barreiro, M.F.; Corcuera, Maria Angeles; Eceiza, ArantaxaPolyurethanes 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 polyure-thane 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.
- Agaricus blazei Murril - a potential ingredient for nutraceutical outcomesPublication . Taofiq, Oludemi; Rodrigues, Francisca; Barros, Lillian; Calhelha, Ricardo C.; González-Paramás, Ana María; Barreiro, M.F.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.The concept of bio-economy has emerged to overcome some sustainability challenges, and this involves conversion of agricultural residues and waste streams into high value-added products that can be utilized as ingredients for several bio-based industrial processes, delivering both economic growth, scientific interest and a better environment. The present work was carried out to re-utilize discarded Agaricus blazei Murill. Its nutritional composition was evaluated and ethanolic extracts were prepared by Soxhlet extraction to be further evaluated for their anti-inflammatory, anti-tyrosinase and cytotoxic properties against different tumor cell lines (SRB assay). MTT and LDH assays were also used to determine cell viability and cell death respectively in Caco-2 and HT29 cells lines. Essential nutrients such as carbohydrates, proteins and fat, were found; twenty fatty acids were detected, sugars (mannitol and trehalose), α-tocopherol and oxalic acid were also present. The extracts, up to 100 μg/mL, were able to maintain viability of Caco-2 and HT29 cells. The extracts also presented anti-tyrosinase activity (EC50 1.33±0.02 mg/mL) and with no toxicity in tumor cells. The results obtained suggested that the extracts obtained from Agaricus blazei Murill residues can be utilized as an inexpensive and sustainable source of nutraceutical and functional food ingredients.
- Agaricus blazei Murrill from Brazil: An ingredient for nutraceutical and cosmeceutical applicationsPublication . Taofiq, Oludemi; Rodrigues, Francisca; Barros, Lillian; Peralta, Rosane M.; Barreiro, M.F.; Ferreira, Isabel C.F.R.; Oliveira, BeatrizOperations for sorting mushrooms at the industrial level usually generate large amounts of bio-residues not conforming to strict morphological criteria for commercial purposes, even though their biological content is not compromised. In this context, the present work aimed at evaluating the potential for reutilizing industrially discarded Agaricus blazei Murill (ABM). Thus, the content of essential nutrients and the chemical composition were determined, and MTT and LDH assays were used to evaluate the viability and cell death of Caco-2 and HT29 cell lines of an ethanolic extract prepared from ABM (preliminary safety tests for nutraceutical applications). The extract was incorporated into a semi-solid base cosmetic cream and cell viability effects of the extract, and of the final cream formulation, on a keratinocyte cell line (HaCaT) were studied (preliminary safety tests for cosmeceutical applications). Essential nutrients, such as proteins and carbohydrates, and a low fat content were determined for ABM. Twenty-two fatty acids were detected, with polyunsaturated fatty acids (PUFA) (∼53%) being the most abundant fraction. The cell viabilities of Caco-2 and HT29 cells were maintained up to 100 μg mL−1. After incorporation into the base cream, a formulation with a pale yellow colour and favourable pH was obtained. The cell viability of HaCaT cells in the presence of the extract and the final cream formulation was maintained in a concentration dependent manner, which indicates the safety of this extract for cosmeceutical applications. The results suggest that ABM residues can be used as an inexpensive and sustainable source of nutraceutical and cosmeceutical ingredients.
- Almond shell-based polyols through oxypropylation reactionPublication . Pinto, João A.; Fernandes, Isabel P.; Barreiro, M.F.Almond cultivation and processing industry generate 3 main types of residues: hull, shell and skin, representing 80% (w/w) of the whole almond fruit. Presently, the shell finds use as energy source being commercialized at a cost of 0.11 €/kg. Hull and skin have no economic value. Apart from the hull, that its use needs a strategy for its recover, both shell and skin can be easily recovered at the almond processing industries and are, therefore, the more attractive residues to develop novel applications. In this work the use of almond shell as a raw material to produce polyols through oxypropylation was studied.
- An integrated process to produce vanillin and lignin-based polyurethanes from Kraft ligninPublication . Silva, Eduardo A.B.; Zabkova, Miriam; Araújo, José D.; Cateto, Carolina; Barreiro, M.F.; Belgacem, Mohamed Naceur; Rodrigues, AlírioThe aim of this manuscript is to present an integrated process that includes reaction and separation steps for producing vanillin and lignin-based polyurethanes from Kraft lignin. It provides details about lignin oxidation and subsequent vanillin recovery, as well as, the synthesis of lignin-based polyurethanes. The oxidation of Kraft lignin in alkaline medium has been carried out in a batch reactor and the optimum operational conditions for vanillin production obtained. The feasibility of a continuous process for vanillin production has been analyzed using a structured bubble column reactor. The generated reaction stream (degraded lignin and sodium vanillate) was further subjected to an ultrafiltration process to recover the vanillate. An ion-exchange process allows recovering the vanillin by passing the vanillate solution through a column packed with an ion-exchange resin in H+ form. The remaining lignin can act as a raw material to produce polyurethanes and/or biofuels. In this work the first approach was explored.
- An overview of teacher training in PortugalPublication . Ferreira, Olga; Silva, Adília T.; Barreiro, M.F.This paper presents an overview of teacher´s training in Portugal concerning initial teacher training (ITE), specialized training and in-service teacher training, as considered by the Portuguese legislation. A special emphasis was given to training in information and communication technologies (ICT) and to teaching of experimental sciences for primary school. Moreover, chemistry teacher’s training was contextualized in this scenario. Presently ITE corresponds to level 7 of the European Qualifications Framework (master degree). It is a career-long professional development, where research-based and in context practice are important features. Nevertheless the implicit valorisation of the teaching career arising from Bologna process implementation, a master degree is needed for all teaching levels; a lack of motivation to pursue teaching careers is generally noticed in Portugal as a consequence of the actual context of a surplus and unemployment among the new teachers. Following ITE, in-service training allows teachers to complement, deepen and update their knowledge and professional competences. This is an important measure for in-service long date teachers’ and particularly relevant for the ones that, following teacher career reorganization, had to readapt to new curricula and even new teaching subjects.
- Análise cromatográfica de iogurte funcionalizado com extrato etanólico de Agaricus bisporusPublication . Francisco, Cristhian Rafael Lopes; Fernandes, Isabel P.; Barreira, João C.M.; Barros, Lillian; Gonçalves, Odinei Hess; Barreiro, M.F.; Ferreira, Isabel C.F.R.Agaricus bisporus (Lange) Imbach é um cogumelo rico em compostos bioativos e os seus extratos podem ser utilizados na funcionalização de alimentos. A caracterização dos extratos e dos alimentos funcionalizados é de extrema importância, principalmente em relação ao teor em compostos bioativos (e.g., ergosterol) e à composição nutricional, respetivamente. Neste trabalho, foi obtido um extrato etanólico de A. bisporus utilizando a técnica de ultrassons para funcionalização de iogurte. O teor em ergosterol foi determinado por cromatografia líquida de alta eficiência (HPLC-UV, Knauer Smartiline 1000) em coluna de fase reversa (Inertsil 100A ODS-3) e acetonitrilo/metanol (70:30, v/v) como fase móvel. O extrato apresentou uma concentração de 19,4 mg ergosterol/g extrato, tendo sido as bandas de absorção características identificadas por FTIR (caracterização estrutural). Posteriormente, o iogurte funcionalizado foi caracterizado em relação à sua composição nutricional e perfis cromatográficos de ácidos gordos e açúcares. O perfil de ácidos gordos foi determinado por cromatografia gasosa (equipamento DANI 1000, Contone) equipado com um detetor de ionização em chama (GC-FID) a 260°C, enquanto que os açúcares foram analisados por HPLC acoplado a um detetor de índice de refração, utilizando como acetonitrilo/água (70:30, v/v) como fase móvel [2]. Não foram observadas alterações significativas em relação ao valor nutricional dos iogurtes funcionalizados em comparação com o controlo (iogurte sem adição do extrato); apresentaram ácido mirístico (C14:0, 11.1±0.4%), ácido palmítico (C16:0, 31±1%), ácido esteárico (C18:0, 10.0±0.5 %) e ácido oleico (C18:1n9, 23±1 %) como ácidos gordos maioritários, e galactose (0.82±0.05 g/100 g) e lactose (4.6±0.2 g/100 g) como açúcares predominantes. No entanto, o extrato conferiu propriedades antioxidantes ao iogurte, demonstrando que a estratégia adotada é promissora para a obtenção de alimentos funcionais.
- Análise de componentes principais aplicada ao estudo da oxipropilação do resíduo da semente da Araucaria angustifóliaPublication . Rezende, Stephany; Pinto, João A.; Fernandes, Isabel P.; Leimann, Fernanda Vitória; Barreiro, M.F.A casca do pinhão brasileiro é um resíduo lenhocelulósico da semente da Araucaria angustifólia, uma espécie de conífera nativa da América do Sul. Esta semente é consumida após sofrer um processo de descasque, resultando na produção de uma quantidade significativa de resíduo sem valor comercial. Tendo por objetivo o desenvolvimento de aplicações para a valorização da casca do pinhão (PFS), este trabalho foca a produção de biopolióis a partir desta fonte lenhocelulósica através do processo de oxipropilação. O trabalho compreendeu o estudo da relação entre as variáveis do processo e as propriedades dos biopoliois, utilizando a metodologia de Análise de Componentes Principais (ACP). No que respeita à oxipropilação, selecionaram-se três razões PFS/óxido de propileno (PO) (30/70, 20/80 e 10/90; m/v). Testaram-se ainda quatro níveis de catalisador: 5, 10, 15 e 20%, (m/m, base biomassa). A oxipropilação ocorreu em condições moderadas de temperatura, pressão e tempo, resultando na produção de poliois líquidos. Numa segunda etapa, procedeu-se à caracterização dos biopoliois, no que respeita ao teor de homopolímero (POO), teor de grupos hidroxilo (IOH), viscosidade (V) e biomassa por reagir (UR) no biopoliol. Posteriormente, através da Análise de Componentes Principais, efetuou-se a avaliação das interações estabelecidas entre as variáveis do processo de oxipropilação e as propriedades dos poliois obtidos. A análise de ACP (Fig. 1) clarificou as interações estabelecidas, provando ser uma ferramenta útil para descrever e visualizar o processo de oxipropilação, com possibilidade de ser estendida a outros tipos de biomassa ou integrando diferentes variáveis de entrada.