Discriminação do perfil aromático de cafés e misturas industriais de acordo com o valor cromático

Different polymeric phases have been used in order to perform roasted coffee aroma analysis although not in a systematic way. Variations in the type of SPME polymer and sample composition make experimental results interpretation difficult and may hinder coffee blend differentiation. In the present work, static headspace solid phase microextraction using carboxen/polydimethylsiloxane polymeric fibre (HS-SPME(CAR/PDMS)) followed by gas chromatography-mass spectrometry (GC-MS), revealed the best analytical performance to characterize the aroma profile of coffees and industrial blends with different chromaticvalues (64.9, 70.6, 75.3, 86.1 and 89.6). The most relevant classes of aroma compounds founded were pyrroles, ketones, pyrazines, furans, phenolics, pyridines, alcohols and acids, independent of the degree of roasting. By combining the analytical methodology with principal component analysis (HS-SPME (CAR/PDMS)/GC-MS/PCA), important aroma compounds such as 2-furancarboxaldehyde, 2-furanmethanol and acetic acid, allows to discriminate the different degrees of roasting, from light (chromatic value 89.6) to dark(chromatic value 64.9) roast. The proposed analytical approach may help to build aroma profile databases to allow a better evaluation of coffee blend quality, and in controlling the industrial roasting processes.Diferentes fases poliméricas têm sido utilizadas, a fim de realizar-se a análise do aroma do café torrado, embora isso não tenha sido feito de forma sistemática. Variações no tipo de polímero de SPME, bem como na composição da amostra tornam a interpretação dos resultados experimentais difícil o que pode inclusive interferir em tentativas de diferenciação de diferentes misturas de café. No presente trabalho, a microextração de fase sólida para análise estática de “espaço-de-cabeça”, utilizando o polímero carboxen/polidimetilsiloxano (HS-SPME (CAR/PDMS)), associada a cromatografia gasosa acoplada a espectrometria de massa (GC-MS), revelou o melhor desempenho analítico na caracterização do perfil aromático de cafés e misturas industriais, com diferentes valores cromáticos (64,9, 70,6, 75,3, 86,1 e 89,6). As classes de compostos aromáticos mais importantes identificadas nos cafés foram: pirróis, cetonas, pirazinas, furanos, fenóis, piridinas, álcoois e ácidos, independentemente do grau de torra. Aocombinar a metodologia analítica com a análise de componentes principais (HS-SPME (CAR/PDMS)/GC-MS/PCA), verificou-se que os compostos aromáticos furancarboxaldeído, 2-furanmethanol e ácido acético permitem discriminar os diferentes graus de torrefação. A abordagem proposta neste estudo pode ajudar a construir bases de dados de perfis aromáticos de uma maneira mais robusta,permitindo uma melhor avaliação da qualidade de misturas de café e melhor controle do processo industrial de torração

Seasonal variations of the nutritive value and phytotherapeutic potential of Cladium mariscus L. (Pohl.) targeting ruminant’s production

In our endeavor to identify salt-tolerant plants with potential veterinary uses in ruminants' production strategies, we focused on Cladium mariscus L. Pohl (sawgrass), due to its high total phenolic and tannin content, anti-radical properties, and ethnomedicinal uses. Aerial parts were collected along the year in Southern Portugal and evaluated for the nutritional profile and in vitro organic matter digestibility (IVOMD), aiming for its use as feed. Acetone extracts were appraised for total contents in phenolics (TPC), flavonoids (TFC), and tannins (CTC), as well as the chemical composition by HPLC-DAD and in vitro antioxidant and anti-inflammatory properties, targeting its exploitation as phytotherapeutic products. Sawgrass biomass has a limited nutritive value, due to its high neutral detergent fiber (NDF; 596-690 g kg-1 dry matter (DM)) and acid detergent fiber (ADF; 330-418 g kg-1 DM) contents, low crude protein (51.8-87.3 g kg-1 DM) and IVOMD (172-317 g kg-1 organic matter (OM)). Despite differences among seasons, the mineral profile was adequate. The extracts were rich in TPC (88-112 mg g-1), CTC (115-169 mg g-1), and TFC (18.5-20.2 mg g-1), and displayed significant antioxidant capacity, particularly in summer and autumn, whilst no seasonal influence was detected for anti-inflammatory properties (30% reduction of nitric oxide production). Eleven phenolics were quantified: chlorogenic, ferulic, and syringic acids were the most abundant, especially in the autumn sample. Overall, despite the low nutritional interest, sawgrass extracts hold the potential as a source of antioxidant and anti-inflammatory phenolic compounds.FCT: GreenVet-ALG-01-0145-FEDER-028876/ UIDB/04326/2020/ SFRH/BD/116604/2016/ CEECIND/00425/2017.info:eu-repo/semantics/publishedVersio

Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red Sea

Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.National Science, Technology and Innovation Program of King Abdulaziz Medical City for Science and Technology, Riyadh, Saudi Arabia [NPST, 11-ENE 1719-02]; Foundation for Science and Technology (FCT), Portugal [SFRH/BD/78062/2011]; FCT [IF/00049/2012, SFRH/BPD/86071/2012, Pest-OE/QUI/UI0612/2013]info:eu-repo/semantics/publishedVersio

Isololiolide, a carotenoid metabolite isolated from the brown alga Cystoseira tamariscifolia, is cytotoxic and able to induce apoptosis in hepatocarcinoma cells through caspase-3 activation, decreased Bcl-2 levels, increased p53 expression and PARP cleavage

Background: Brown macroalgae have attracted attention because they display a wide range of biological activities, including antitumoral properties. In this study we isolated isololiolide from Cystoseira tamariscifolia for the first time.Purpose: To examine the therapeutical potential of isololiolide against tumor cell lines.Methods/Study design: The structure of the compound was established and confirmed by 1D and 2D NMR as well as HRMS spectral analysis. The in vitro cytotoxicity was analyzed by colorimetric 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay in tumoral as well as in non-tumoral cell lines. Cell cycle arrest and induction of apoptosis were assessed by flow cytometry. Alteration of expression levels in proteins important in the apoptotic cascade was analyzed by western blotting.Results: Isololiolidewas isolated for the first time from the brown macroalga C. tamariscifolia. Isololiolide exhibited significant cytotoxic activity against three human tumoral cell lines, namely hepatocarcinoma HepG2 cells, whereas no cytotoxicity was found in non-malignant MRC-5 and HFF-1 human fibroblasts. Isololiolide completely disrupted the HepG2 normal cell cycle and induced significant apoptosis. Moreover, western blot analysis showed that isololiolide altered the expression of proteins that are important in the apoptotic cascade, increasing PARP cleavage and p53 expression while decreasing procaspase-3 and Bcl-2 levels.Conclusion: Isololiolide isolated from C. tamariscifolia is able to exert a selective cytotoxic activity on hepatocarcinoma HepG2 cells as well as induce apoptosis through the modulation of apoptosis-related proteins. (C) 2016 Elsevier GmbH. All rights reserved

Trace analysis of carbazole in commercial diesel by using adsorption on activated biochar from rice husk pyrolysis

The valorization of rice husk biochar obtained by pyrolysis was studied by production high quality activated carbon. Activated carbon (AC) chemically treated by K2CO3, was used as sorbent phase in bar adsorptive microextraction followed by comprehensive two-dimensional gas chromatography coupled to a quadrupole mass spectrometer analysis (BAμE/GC×GC-qMS) for trace analysis of carbazole in commercial diesel. The prepared AC was characterized by N2 adsorption, SEM-EDS and pHPZC. Assays of nitrogen adsorption isotherm demonstrated that the AC presented microporosity and the Density Functional Theory Calculation was applied to obtain information concerning the micropore size distribution. The BET surface area and total pore volume were 1850 m2g-1and 0.83 cm3g-1, respectively. AC from rice huskpyrolysis (RH) showed an acceptable adsorption capacity for Carbazole in diesel matrices allowed us to obtain average recoveries of 91.0 % and convenient analytical parameters. From the data obtained, the proposed methodology proved to be a suitable sorption-based static microextraction alternative for monitoring trace levels of carbazole in commercial diesel

<i>In vitro</i> antioxidant and inhibitory activity of water decoctions of carob tree (<i>Ceratonia siliqua</i> L.) on cholinesterases, α-amylase and α-glucosidase

<div><p>This work reports the <i>in vitro</i> inhibitory activity of water decoctions of leaves, germ flour, pulp, locust bean gum and stem bark of carob tree on α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase. The antioxidant activity and the chemical characterisation of the extracts made by spectrophotometric assays and by high-performance liquid chromatography are also reported. Leaves and stem bark decoctions strongly inhibited all the enzymes tested, had significant antioxidant activity and the highest total phenolics content. The major compounds were identified as gallic acid in the leaves and gentisic acid in the stem bark.</p></div

Trace analysis of carbazole in commercial diesel by using adsorption on activated biochar from rice husk pyrolysis

The valorization of rice husk biochar obtained by pyrolysis was studied by production high quality activated carbon. Activated carbon (AC) chemically treated by K2CO3, was used as sorbent phase in bar adsorptive microextraction followed by comprehensive two-dimensional gas chromatography coupled to a quadrupole mass spectrometer analysis (BAμE/GC×GC-qMS) for trace analysis of carbazole in commercial diesel. The prepared AC was characterized by N2 adsorption, SEM-EDS and pHPZC. Assays of nitrogen adsorption isotherm demonstrated that the AC presented microporosity and the Density Functional Theory Calculation was applied to obtain information concerning the micropore size distribution. The BET surface area and total pore volume were 1850 m2g-1and 0.83 cm3g-1, respectively. AC from rice huskpyrolysis (RH) showed an acceptable adsorption capacity for Carbazole in diesel matrices allowed us to obtain average recoveries of 91.0 % and convenient analytical parameters. From the data obtained, the proposed methodology proved to be a suitable sorption-based static microextraction alternative for monitoring trace levels of carbazole in commercial diesel

Phytochemical Profile, Antioxidant and Cytotoxic Activities of the Carob Tree (Ceratonia siliqua L.) Germ Flour Extracts

This work aimed to evaluate the phytochemical content and to determine the antioxidant and cytotoxic activities of methanol extracts of the carob tree (Ceratonia siliqua L.) germ flour. The extracts were rich in phenolic compounds, had considerable antioxidant activity, and reduced the viability of cervical (HeLa) cancer cells. The chemical content and the biological activities of the extracts were significantly affected by gender and cultivar. Female cultivar Galhosa had the highest levels of phenolic compounds, and the highest antioxidant activity. Extracts from the hermaphrodite trees and from the female cultivars Galhosa and Costela/Canela exhibited the highest cytotoxic activity. The most abundant compound was theophylline. The phenolic content was correlated to both antioxidant and cytotoxic activities. Our findings provide new knowledge about the health implications of consuming food supplemented with carob germ flour