235 research outputs found
Chlorophyll-based coloring extracts obtained from biowaste
The growing consumers‘ concern about the possible long-term adverse effects of artificial
molecules commonly used in the food industry has led to an increased interest in natural
products. At the same time, there is a demand for a more eco-sustainable use of natural
matrices, which justifies the search for by-products that have no other application to be
explored in the development of new food products [1,2]. In this context, the present study
aimed to explore natural pigments, more specifically chlorophylls, from carrot and tomato
aerial part biowaste for the development of food dyes as they are the most abundant pigments
in plants and have several bioactive properties. In this work, maceration extraction, ME, and
ultrasound assisted extraction, USE, techniques were applied to lyophilized aerial parts of
biowaste to maximize the yield of chlorophyll extraction. For the extraction processes,
priority was given to green solvents, namely water, ethanol (90%), and hexane. The
parameters that affect the recovery of pigments were varied for each technique, more
specifically the time, ultrasonic power, and solvent for USE, and the time and solvent for ME.
The extractions were performed protecting the samples from light and the results were
monitored through the implementation of a new chromatographic method, HPLC coupled to
a diode array detector (DAD) and mass spectrometry (MS), in order to determine the
concentration of chlorophylls and the best procedure to be performed. Both aerial parts
presented chlorophylls and derivatives in significant concentrations and extraction yields of
up to 88% for the ethanol extracts. The chromatographic method applied proved to be
adequate for the analysis of this class of pigments, allowing a good resolution and peak
separation, but also a characteristic TIC spectrum for the tentative identification of
compounds. Therefore, the results of the present study can be exploited for the development
of chlorophyll-based dyes from these biowaste, but also from similar by-productsThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for
financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020).
National funding by FCT, P.I., through the institutional scientific employment
program-contract for C. Pereira, M.I. Dias, and L. Barros contracts and A.K. Molina PhD
grant (2020.06231.BD). To FEDER-Interreg España-Portugal programme for financial
support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P; to the European
Regional Development Fund (ERDF) through the Regional Operational Program North 2020,
within the scope of Project Mobilizador Norte-01-0247-FEDER-024479: ValorNaturalinfo:eu-repo/semantics/publishedVersio
Extraction of chlorophylls from natural sources
The growing consumers’ concern for possible long-term adverse effects of artificial molecules commonly
used in food industry has led to an increased interest in natural products. At the same time, there is a demand
for a more eco-sustainable use of natural matrices, which justifies the search for byproducts that have no
other application to be explored in the development of novel food products [1,2]. In this context, the present
study was designed to exploit natural pigments, more specifically chlorophylls, from bioresidues (aerial
parts of carrot and tomato) for the development of food colorants. These are the most abundant pigments in
plants and present, beyond their great coloring capacity, several bioactive properties, which corroborates
the importance of their application in foodstuff. In this work, different extraction methodologies and
techniques (maceration, ME, and ultrasound-assisted, USE) were applied to the lyophilized aerial parts of
carrot and tomato to maximize the chlorophyll extraction yield. For the extraction, green solvents were
prioritized, namely water, ethanol (90%), and hexane. The parameters affecting the pigments recovery were
varied for each technique, namely the time, power, and solvent for USE, and the time and solvent for ME.
The extractions were performed protecting the samples from light and the results were monitored through
the implementation of a new chromatographic method, HPLC coupled to a diode array detector (DAD) and
mass spectrometry (MS), to determine the concentration of chlorophylls and the best procedure to be
performed. Both aerial parts presented chlorophylls and derivatives in significant concentrations and
extraction yields up to 88% for the ethanolic extracts. The applied chromatographic method revealed to be
appropriate for the analysis of this class of pigments, allowing a good peak resolution and separation, but
also characteristic TIC spectrum for the tentative identification of the compounds. Therefore, the results of
the present study can be explored for the development of chlorophyl-based colorants from these bioresidues,
but also from similar byproducts.To the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO
(UIDB/00690/2020); National funding by FCT, P.I., through the individual scientific employment program-contract for C. Pereira,
M.I. Dias, and L. Barros contracts and A.K. Molina PhD grant (2020.06231.BD). To FEDER-Interreg España-Portugal programme
for financial support through the project 0377_Iberphenol_6_E and TRANSCoLAB 0612_TRANS_CO_LAB_2_P; to the European
Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project
Mobilizador Norte-01-0247-FEDER-024479: ValorNatural® and Project GreenHealth - Norte-01-0145-FEDER-000042info:eu-repo/semantics/publishedVersio
Development of sustainable techniques for cellulose recovery from leftovers and cellulose-containing garments
[Excerpt] Introduction Textile and clothing industry is one of the most polluting industries in
the world, with high impact on water and land consumption.
Approximately 5.8 million tons of textiles are discarded in Europe,
and only 1% is fiber-to-fiber recycled.This research was funded by FEDER funds through the Operational Competitiveness Program–COMPETE, under the project POCI-01-0247-FEDER047124, and by National Funds through Fundação para a Ciência e Tecnologia (FCT), under the project UID/CTM/00264/2020. Talita Nicolau and Cátia Alves acknowledge FCT, MCTES, FSE and UE PhD grants 2022.15386.BD and 2022.10454.BD, respectively
Estudo nutricional e químico dos frutos de Rubus fruticosus L. var. ‘Triple Crown’ como fonte alimentar com alta capacidade antioxidante
Os frutos de Rubus fruticosus L. var. ‘Triple Crown’ (amora) são de grande interesse na indústria alimentar
devido ao seu elevado teor em compostos bioativos, sendo possível a sua utilização em novos produtos de
origem natural como aditivos alimentares, para além das suas propriedades nutricionais serem benéficas para
a saúde do consumidor. Neste estudo, os frutos de R. fruticosus foram avaliados quanto ao seu valor
nutricional (métodos AOAC), composição em açúcares livres (HPLC-RI), ácidos orgânicos (UFLC-PDA) e
ácidos gordos (GC-FID), bem como em relação ao seu teor em antocianinas (HPLC-DAD-ESI/MS) e
propriedades antioxidantes (TBARS e OxHLIA).Os autores agradecem à Fundação para a Ciência e a Tecnologia (FCT, Portugal) e aos fundos nacionais FCT/MCTES pelo apoio financeiro ao CIMO (UIDB/00690/2020). Financiamento nacional pela FCT, P.I., no âmbito da celebração do contrato-programa de emprego científico institucional, pelos contratos de C. Pereira, M.I. Dias e L. Barros e bolsa de doutoramento de A.K. Molina
(2020.06231.BD). Ao programa FEDER-Interreg España-Portugal pelo apoio financeiro através do projeto TRANSCoLAB0612_TRANS_CO_LAB_2_P.N/
O TURISMO E A FALTA D’ÁGUA EM SÃO FRANCISCO DO SUL, SC
O problema no saneamento básico da cidade de São Francisco do Sul é algo recorrente, ocorrendo todos os anos, tornando se mais presente na praia da Enseada. O objetivo da pesquisa é saber como os moradores da praia da Enseada, sentem se diante a falta d’água na alta temporada. A pesquisa utilizou se do Modelo de Doxey para identificar a satisfação dos moradores em relação ao turismo. Conclui se que ap esar dos moradores apontarem o turismo como um dos motivos da falta d’água. A pesquisa aponta que a insatisfação dos entrevistados se deve à falta de infraestrutura da cidade e não ao fluxo turístico.
 
DA TECTÓNICA DE PLACAS À TEORIA DA EVOLUÇÃO; DOS SUPERCONTINENTES À DISPERSÃO DOS SERES VIVOS
Na última década a evolução do conhecimento do comportamento das camadas internas do nosso planeta tem levado
a profundas alterações da forma como a dinâmica da Terra é encarada. O ênfase nas células de convecção lineares e
na movimentação das placas tectónicas expressa nos ciclos de Wilson, tem evoluídos lentamente para uma
aproximação onde as enormes plumas convectivas (quentes e frias) e o ciclo dos supercontinentes aparecem como
processos dominantes. Esta transformação tem permitido uma visão mais integradora, onde os processos tectónicos e
de evolução da Vida na Terra surgem, não como processos isolados, mas sim como complementares. No entanto, esta
nova abordagem ainda não se reflecte nos curricula do ensino.
Neste trabalho propõe-se um conjunto de actividades práticas para o ensino secundário explorando o conceito do ciclo
dos supercontinentes e da dispersão da Vida na Terra. A reconstrução da dispersão dos principais blocos continentais
desde a Rodinia até à Actualidade permite perceber, não apenas a agregação e dispersão dos supercontinentes
(Rodinia Panotia Pangeia), mas também e a sua influência na dispersão de alguns dos principais grupos de seres
vivos na Terra. Com efeito, a existência da Panotia é fundamental para perceber a distribuição das primeiras trilobites no
Câmbrico inferior, a agregação da Pangeia é crucial para perceber a dispersão dos tetrápodes na Terra e a existência
deste último supercontinente explica porque existem fósseis de dinossáurios em todos os continentes
Low resolution structures of the retinoid X receptor DNA-binding and ligand-binding domains revealed by synchrotron x-ray solution scattering
Nuclear receptors are ligand-inducible transcription factors that share structurally related DNA-binding (DBD) and ligand-binding (LBD) domains. Biochemical and structural studies have revealed the modular nature of DBD and LBD. Nevertheless, the domains function in concert in vivo. While high-resolution crystal structures of nuclear receptor DBDs and LBDs are available, there are no x-ray structural studies of nuclear receptor proteins containing multiple domains. We report the solution structures of the human retinoid X receptor DBD-LBD (hRXR AB) region. We obtained ab initio shapes of hRXR AB dimer and tetramer to 3.3 and 1.7 nm resolutions, respectively, and established the position and orientation of the DBD and LBD by fitting atomic coordinates of hRXR DBD and LBD. The dimer is U-shaped with DBDs spaced at 2 nm in a head to head orientation forming an angle of about 10° with respect to each other and with an extensive interface area provided by the LBD. The tetramer is a more elongated X-shaped molecule formed by two dimers in head to head arrangement in which the DBDs are extended from the structure and spaced at about 6 nm. The close proximity of DBDs in dimers may facilitate homodimer formation on DNA; however, for the homodimer to bind to a DNA element containing two directly repeated halfsites, one of the DBDs would need to rotate with respect to the other element. By contrast, the separation of DBDs in the tetramers may account for their decreased ability to recognize DNA
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