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1.
J Inherit Metab Dis ; 47(4): 731-745, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38356271

RESUMO

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most prevalent mitochondrial fatty acid ß-oxidation disorder. In this study, we assessed the variability of the lipid profile in MCADD by analysing plasma samples obtained from 25 children with metabolically controlled MCADD (following a normal diet with frequent feeding and under l-carnitine supplementation) and 21 paediatric control subjects (CT). Gas chromatography-mass spectrometry was employed for the analysis of esterified fatty acids, while high-resolution C18-liquid chromatography-mass spectrometry was used to analyse lipid species. We identified a total of 251 lipid species belonging to 15 distinct lipid classes. Principal component analysis revealed a clear distinction between the MCADD and CT groups. Univariate analysis demonstrated that 126 lipid species exhibited significant differences between the two groups. The lipid species that displayed the most pronounced variations included triacylglycerols and phosphatidylcholines containing saturated and monounsaturated fatty acids, specifically C14:0 and C16:0, which were found to be more abundant in MCADD. The observed changes in the plasma lipidome of children with non-decompensated MCADD suggest an underlying alteration in lipid metabolism. Therefore, longitudinal monitoring and further in-depth investigations are warranted to better understand whether such alterations are specific to MCADD children and their potential long-term impacts.


Assuntos
Acil-CoA Desidrogenase , Erros Inatos do Metabolismo Lipídico , Lipidômica , Fosfolipídeos , Triglicerídeos , Humanos , Erros Inatos do Metabolismo Lipídico/sangue , Lipidômica/métodos , Criança , Masculino , Feminino , Triglicerídeos/sangue , Fosfolipídeos/sangue , Pré-Escolar , Acil-CoA Desidrogenase/deficiência , Lactente , Adolescente , Metabolismo dos Lipídeos , Estudos de Casos e Controles , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Carnitina/sangue
2.
Mol Omics ; 19(1): 35-47, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36314173

RESUMO

Lipidomics represent a valid complementary tool to the biochemical analysis of plasma in humans. However, in cetaceans, these tools have been unexplored. Here, we evaluated how the plasma lipid composition of Tursiops truncatus is modulated by developmental stage and sex, aiming at a potential use of lipidomics in integrated strategies to monitor cetacean health. We characterized the fatty acid profile and detected a total of 26 fatty acids in T. truncatus plasma. The most abundant fatty acids were palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1n-9). Interestingly, there are consistent differences between the fatty acid profile of mature female and mature male specimens. Phospholipidome analysis identified 320 different lipid species belonging to phosphatidylcholine (PC, 105 lipid species), lysophosphatidylcholine (42), phosphatidylethanolamine (PE, 67), lysophosphatidylethanolamine (18), phosphatidylglycerol (14), lysophosphatidylglycerol (8), phosphatidylinositol (14), lysophosphatidylinositol (2), phosphatidylserine (3), sphingomyelin (45) and ceramides (2) classes. The statistical analysis of the phospholipidome showed that its composition allows discriminating mature animals between sexes and mature males from immature males. Notably, discrimination between sexes is mainly determined by the contents of PE plasmalogens and lysophospholipids (LPC and LPE), while the differences between mature and immature male animals were mainly determined by the levels of PC lipids. This is the first time that a correlation between developmental stage and sex and the lipid composition of the plasma has been established in cetaceans. Being able to discern between age and sex-related changes is an encouraging step towards using these tools to also detect differences related to disease/dysfunction processes.


Assuntos
Golfinho Nariz-de-Garrafa , Humanos , Animais , Masculino , Feminino , Ácidos Graxos , Lisofosfatidilcolinas , Ceramidas
3.
Int J Mol Sci ; 22(18)2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34576003

RESUMO

Noncommunicable diseases (NCD) and age-associated diseases (AAD) are some of the gravest health concerns worldwide, accounting for up to 70% of total deaths globally. NCD and AAD, such as diabetes, obesity, cardiovascular disease, and cancer, are associated with low-grade chronic inflammation and poor dietary habits. Modulation of the inflammatory status through dietary components is a very appellative approach to fight these diseases and is supported by increasing evidence of natural and dietary components with strong anti-inflammatory activities. The consumption of bioactive lipids has a positive impact on preventing chronic inflammation and consequently NCD and AAD. Thus, new sources of bioactive lipids have been sought out. Microalgae are rich sources of bioactive lipids such as omega-6 and -3 polyunsaturated fatty acids (PUFA) and polar lipids with associated anti-inflammatory activity. PUFAs are enzymatically and non-enzymatically catalyzed to oxylipins and have a significant role in anti and pro-resolving inflammatory responses. Therefore, a large and rapidly growing body of research has been conducted in vivo and in vitro, investigating the potential anti-inflammatory activities of microalgae lipids. This review sought to summarize and critically analyze recent evidence of the anti-inflammatory potential of microalgae lipids and their possible use to prevent or mitigate chronic inflammation.


Assuntos
Envelhecimento/efeitos dos fármacos , Misturas Complexas/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Ácidos Graxos Ômega-6/uso terapêutico , Microalgas/química , Doenças não Transmissíveis/tratamento farmacológico , Misturas Complexas/química , Ácidos Graxos Ômega-3/química , Ácidos Graxos Ômega-6/química , Humanos , Inflamação/tratamento farmacológico
4.
J Proteome Res ; 20(5): 2651-2661, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33819046

RESUMO

Phenylketonuria (PKU) is a disease of the catabolism of phenylalanine (Phe), caused by an impaired function of the enzyme phenylalanine hydroxylase. Therapeutics is based on the restriction of Phe intake, which mostly requires a modification of the diet. Dietary restrictions can lead to imbalances in specific nutrients, including lipids. In the present study, the plasma phospholipidome of PKU and healthy children (CT) was analyzed by hydrophilic interaction liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Using this approach, 187 lipid species belonging to nine different phospholipid classes and three ceramides were identified. Principal component analysis of the lipid species data set showed a distinction between PKU and CT groups. Univariate analysis revealed that 146 species of phospholipids were significantly different between both groups. Lipid species showing significant variation included phosphatidylcholines, containing polyunsaturated fatty acids (PUFA), which were more abundant in PKU. The high level of PUFA-containing lipid species in children with PKU may be related to a diet supplemented with PUFA. This study was the first report comparing the plasma polar lipidome of PKU and healthy children, highlighting that the phospholipidome of PKU children is significantly altered compared to CT. However, further studies with larger cohorts are needed to clarify whether these changes are specific to phenylketonuric children.


Assuntos
Fenilcetonúrias , Criança , Dieta , Suplementos Nutricionais , Ácidos Graxos Insaturados , Humanos , Fenilalanina , Fenilcetonúrias/diagnóstico
5.
Crit Rev Food Sci Nutr ; 61(8): 1305-1339, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32393054

RESUMO

Thousands of tons of fruit seeds are discarded every year worldwide as agro-industrial byproducts. Fruit seeds have a high oil content, are rich in monounsaturated fatty acids (FA) and in n-6 and n-3 polyunsaturated essential FA. Sterols, phospholipids, glycolipids, carotenoids, tocopherols and polyphenols are other seed phytochemicals that make them interesting from a commercial viewpoint. Fruit seeds have high potential as raw material for several industries, but their lipid profile remains poorly studied. Current analytical approaches for the analysis of lipids that are based on high-performance liquid chromatography and high-resolution mass spectrometry allow the separation and analysis of compounds with the accurate identification and structural characterization of molecular species in very small quantities. Even though lipidomic analysis of fruit seeds' lipids is still in its infancy, it will bring a new look over these value-added byproducts. This review covers the following topics: (a) the lipid content of various fruit seed oils; (b) their lipid composition (FA, triacylglycerol, sterol, phospholipid and glycolipid profiles), (c) current and future analytical methodologies for the analysis of lipids in fruit seeds; (d) biological activities of fruit seeds' extracts; and (e) potential biotechnological applications of fruit seed oils for their commercial valorization based on lipids.


Assuntos
Frutas , Fitosteróis , Ácidos Graxos , Óleos de Plantas , Tocoferóis , Triglicerídeos
6.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916896

RESUMO

UVB phototherapy is treatment for psoriasis, which increases phospholipid oxidative modifications in the cell membrane of the skin. Therefore, we carried out lipidomic analysis on the keratinocytes of healthy individuals and patients with psoriasis irradiated with UVB and treated with cannabidiol (CBD), phytocannabinoid with antioxidant and anti-inflammatory properties. Our results showed that, in psoriatic keratinocytes phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylserine (PS), and ether-linked phosphoethanolamine (PEo), were downregulated, while SM (d41:2) was upregulated. These changes were accompanied by an increase in negative zeta potential, which indicates translocation of PS to the outer layer of the membrane. CBD treatment of psoriatic keratinocytes led to downregulation of PC, PS, and upregulation of certain PEo and an SM species, SM (d42:2), and the zeta potential. However, UVB irradiation of psoriatic keratinocytes resulted in upregulation of PC, PC plasmalogens (PCp), PEo, and a decrease in the negative zeta potential. The exposure of UVB-irradiated cells to CBD led to a decrease in the level of SM (d42:2). Our results suggest that CBD induces pro-apoptotic mechanisms in psoriatic keratinocytes while simultaneously improving the antioxidant properties and preventing the loss of transepidermal water of keratinocytes of patients irradiated with UVB. Thus, CBD has potential therapeutic value in the treatment of psoriasis.


Assuntos
Canabidiol/uso terapêutico , Queratinócitos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fosfolipídeos/metabolismo , Psoríase/tratamento farmacológico , Adulto , Canabidiol/farmacologia , Estudos de Casos e Controles , Feminino , Humanos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Metabolismo dos Lipídeos/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Cultura Primária de Células , Psoríase/metabolismo , Psoríase/radioterapia , Raios Ultravioleta , Terapia Ultravioleta , Adulto Jovem
7.
Mar Drugs ; 18(4)2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32244516

RESUMO

In the last decades, the use of algae in biotechnology and food industries has experienced an exponential growth. Codium tomentosum is a green macroalgae with high biotechnological potential, due to its rich lipidome, although few studies have addressed it. This study aimed to investigate the seasonal changes in lipid and pigment profiles of C. tomentosum, as well as to screen its antioxidant activity, in order to evaluate its natural plasticity. Samples of C. tomentosum were collected in two different seasons, early-autumn (September/October) and spring (May), in the Portuguese coast (wild samples), and in a land-based integrated multitrophic aquaculture (IMTA) system (IMTA samples). Total lipid extracts were analysed by LC-MS, GC-MS, and HPLC, and antioxidant activity was screened through free radical scavenging potential against DPPH and 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Wild samples showed a high seasonal variability, modifying their lipidome and pigment profiles according to environmental shifts, while IMTA samples showed a relatively stable composition due to early-stage culturing in controlled conditions. The lipids that contributed the most to seasonal discrimination were glycolipids (monogalactosyl diacylglycerol - MGDG and digalactosyl diacylglycerol - DGDG) and the lyso forms of phospholipids and glycolipids. Lipid extracts showed antioxidant activity ranging from 61 ± 2 to 115 ± 35 µmol Trolox g-1 of lipid extract in DPPH assay and from 532 ± 73 to 927 ± 92 µmol Trolox g-1 of lipid extract in ABTS assay, with a more intense antioxidant activity in wild spring samples. This study revealed that wild specimens of C. tomentosum presented a higher plasticity to cope with seasonal environmental changes, adjusting their lipid, pigment, and bioactivity profiles, while IMTA samples, cultured under controlled conditions, displayed more stable lipidome and pigment compositions.


Assuntos
Clorófitas/química , Sequestradores de Radicais Livres/farmacologia , Lipídeos/farmacologia , Extratos Vegetais/farmacologia , Alga Marinha/química , Aquicultura , Benzotiazóis/antagonistas & inibidores , Biotecnologia/métodos , Compostos de Bifenilo/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Sequestradores de Radicais Livres/isolamento & purificação , Lipídeos/isolamento & purificação , Espectrometria de Massas , Picratos/antagonistas & inibidores , Extratos Vegetais/isolamento & purificação , Estações do Ano , Ácidos Sulfônicos/antagonistas & inibidores
8.
Mar Drugs ; 17(9)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540326

RESUMO

Palmaria palmata is an edible red macroalga widely used for human consumption and valued for its high protein value. Despite its low total lipid content, it is rich in eicosapentaenoic acid (EPA). This seaweed has been scarcely explored with regard to its lipid composition. The polar lipids of seaweeds are nowadays recognized as important phytochemicals contributing to their add value valorization and providing support for claims of potential health benefits. The present study aimed to disclose the polar lipid profile of P. palmata, farmed in an integrated multi-trophic aquaculture (IMTA) through modern lipidomic approaches using high-resolution LC-MS and MS/MS and to screen for the antioxidant properties of this red macroalga. A total of 143 molecular species of lipids were identified, belonging to several classes of polar lipids, such as glycolipids, phospholipids, and betaine lipids. It is noteworthy that the most abundant lipid species in each class were esterified with eicosapentaenoic acid (EPA), accounting for more than 50% of the lipid content. The polar lipid extract rich in EPA showed antioxidant activity with an inhibition concentration (IC) of IC30 = 171 ± 19.8 µg/mL for α,α-diphenyl-ß-picrylhydrazyl radical (DPPH●) and IC50 = 26.2 ± 0.1 µg/mL for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS●+). Overall, this study highlights that P. palmata farmed in an IMTA framework can be a sustainable source of beneficial lipids with antioxidant activity. Moreover, this red macroalga can be exploited for future applications as a source of lipids rich in EPA for food and feed, nutraceuticals, and cosmetics.


Assuntos
Ácido Eicosapentaenoico/análise , Sequestradores de Radicais Livres/farmacocinética , Extratos Vegetais/farmacologia , Rodófitas/química , Alga Marinha/química , Aquicultura , Cromatografia Líquida de Alta Pressão , Cosméticos , Suplementos Nutricionais , Sequestradores de Radicais Livres/análise , Sequestradores de Radicais Livres/química , Alimento Funcional , Concentração Inibidora 50 , Lipidômica , Extratos Vegetais/análise , Extratos Vegetais/química , Espectrometria de Massas em Tandem
9.
Food Chem ; 227: 422-431, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28274453

RESUMO

Under roasting conditions, polysaccharides depolymerize and also are able to polymerize, forming new polymers through non-enzymatic transglycosylation reactions (TGRs). TGRs can also occur between carbohydrates and aglycones, such as the phenolic compounds present in daily consumed foods like coffee. In this study, glycosidically-linked phenolic compounds were quantified in coffee melanoidins, the polymeric nitrogenous brown-colored compounds formed during roasting, defined as end-products of Maillard reaction. One third of the phenolics present were in glycosidically-linked form. In addition, the roasting of solid-state mixtures mimicking coffee beans composition allowed the conclusion that proteins play a regulatory role in TGRs extension and, consequently, modulate melanoidins composition. Overall, the results obtained showed that TGRs are a main mechanism of phenolics incorporation in melanoidins and are inhibited by amino groups through Maillard reaction.


Assuntos
Coffea/química , Fenóis/química , Polímeros/química , Carboidratos/química , Café/química , Glicosilação , Temperatura Alta , Reação de Maillard
10.
J Agric Food Chem ; 64(8): 1831-40, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26855252

RESUMO

Three mixtures containing different molar proportions of (ß1→4)-D-mannotriose and (α1→5)-L-arabinotriose, oligosaccharides structurally related to coffee polysaccharides (galactomannans and arabinogalactans), were roasted at 200 °C for different periods. Electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS(n)) analyses of labeled ((18)O) and unlabeled samples allowed identification of not only nonhybrid oligosaccharides but also hybrid oligosaccharides composed of both hexose and pentose units. The identification of hybrid oligosaccharides allowed us to infer the occurrence of nonenzymatic transglycosylation reactions involving both oligosaccharides in the starting mixtures. Also, it was observed that using different proportions of the oligosaccharides in the starting mixtures and extents of thermal treatment led to a variation in the composition of the compounds formed. These results have led to the conclusion that, depending on the distribution of the polysaccharides in the bean cell walls and the roasting conditions, different nonhybrid and hybrid structures can be formed during coffee roasting.


Assuntos
Coffea/química , Extratos Vegetais/química , Polissacarídeos/química , Sementes/química , Culinária , Glicosilação , Temperatura Alta , Espectrometria de Massas , Estrutura Molecular
11.
Food Chem ; 185: 135-44, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25952851

RESUMO

Arabinose from arabinogalactan side chains was hypothesized as a possible binding site for chlorogenic acids in coffee melanoidins. To investigate this hypothesis, a mixture of 5-O-caffeoylquinic acid (5-CQA), the most abundant chlorogenic acid in green coffee beans, and (α1 → 5)-L-arabinotriose, structurally related to arabinogalactan side chains, was submitted to dry thermal treatments. The compounds formed during thermal processing were identified by electrospray ionization mass spectrometry (ESI-MS) and characterized by tandem MS (ESI-MS(n)). Compounds composed by one or two CQAs covalently linked with pentose (Pent) residues (1-12) were identified, along with compounds bearing a sugar moiety but composed exclusively by the quinic or caffeic acid moiety of CQAs. The presence of isomers was demonstrated by liquid chromatography online coupled to ESI-MS and ESI-MS(n). Pent1-2CQA were identified in coffee samples. These results give evidence for a diversity of chlorogenic acid-arabinose hybrids formed during roasting, opening new perspectives for their identification in melanoidin structures.


Assuntos
Arabinose/análise , Ácido Clorogênico/análise , Café/química , Polímeros/química , Ácido Clorogênico/análogos & derivados , Ácido Clorogênico/química , Cromatografia Líquida de Alta Pressão , Manipulação de Alimentos , Galactanos/química , Temperatura Alta , Pentoses/análise , Ácido Quínico/análogos & derivados , Ácido Quínico/química , Espectrometria de Massas por Ionização por Electrospray
12.
Bioresour Technol ; 177: 87-93, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25479398

RESUMO

In this work, biosurfactant production by a Pseudomonas aeruginosa strain was optimized using low-cost substrates. The highest biosurfactant production (3.2 g/l) was obtained using a culture medium containing corn steep liquor (10% (v/v)) and molasses (10% (w/v)). The biosurfactant reduced the surface tension of water up to 30 mN/m, and exhibited a high emulsifying activity (E24=60%), with a critical micelle concentration as low as 50 mg/l. The biosurfactant produced in this alternative medium was characterized as a mixture of eight different rhamnolipid congeners, being the most abundant the mono-rhamnolipid Rha-C10-C10. However, using LB medium, nine different rhamnolipid congeners were identified, being the most abundant the di-rhamnolipid Rha-Rha-C10-C10. The rhamnolipid mixture produced in the alternative medium exhibited a better performance in removing oil from contaminated sand when compared with two chemical surfactants, suggesting its potential use as an alternative to traditional chemical surfactants in enhanced oil recovery or bioremediation.


Assuntos
Agricultura , Biotecnologia/métodos , Glicolipídeos/química , Resíduos Industriais/análise , Petróleo/análise , Biodegradação Ambiental , Meios de Cultura , Emulsões , Dados de Sequência Molecular , Pseudomonas aeruginosa/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Tensão Superficial , Tensoativos/metabolismo
13.
Carbohydr Polym ; 112: 48-55, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25129715

RESUMO

Aiming to investigate the possible occurrence of transglycosylation reactions between galactomannans and side chains of arabinogalactans during coffee roasting, mixtures of ß-(1 → 4)-D-mannotriose and α-(1 → 5)-L-arabinotriose were subjected to dry thermal treatments at 200 °C. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis allowed identifying polysaccharides composed by pentose and hexose residues with a degree of polymerization up to 18 residues. Methylation analysis showed the occurrence of new types of glycosidic linkages in all thermally treated mixtures, as well as the occurrence of terminally and 5-linked ribose, possibly formed from arabinose isomerization. Also, xylose and lyxose were identified and proposed to be formed from mannose. These results support the occurrence of transglycosylation reactions promoted by roasting involving both oligosaccharides in the starting mixtures, resulting in arabinan and mannan chimeric polysaccharides. These structural features were also found in roasted coffee polysaccharide samples.


Assuntos
Café/química , Galactanos/química , Mananas/química , Trissacarídeos/química , Configuração de Carboidratos , Manipulação de Alimentos/métodos , Galactose/análogos & derivados , Glicosilação , Temperatura Alta , Hidrólise , Oligossacarídeos/química , Oxirredução , Pentoses/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
J Agric Food Chem ; 62(31): 7843-53, 2014 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-24998624

RESUMO

Phenolic compounds are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different melanoidin populations being observed. The incorporation of phenolic compounds into coffee melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compounds can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.


Assuntos
Café/química , Fenóis/análise , Polímeros/química , Cafeína/análise , Ácido Clorogênico/análise , Ácido Clorogênico/química , Coffea/química , Manipulação de Alimentos/métodos , Temperatura Alta , Fenóis/química , Sementes/química
15.
Carbohydr Polym ; 103: 333-8, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24528737

RESUMO

The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 °C for 3 min. With MAE3, mannose recovery achieved 48%, increasing to 56% by MAE4, and reaching a maximum of 69% with MAE5. Glycosidic-linkage analysis showed that in MAE3 mainly galactomannans were recovered, while debranched galactomannans were recovered with MAE4 and MAE5. With increasing the number of extractions, the average degree of polymerization of the mannans decreased, as observed by size-exclusion chromatography and by methylation analysis. Scanning electron microscopy images showed a decrease on cell walls thickness. After final MAE5, the remaining un-extracted insoluble material, representing 22% of the initial SCG, was composed mainly by cellulose (84%).


Assuntos
Café/química , Mananas/isolamento & purificação , Micro-Ondas , Água/química , Mananas/química
16.
Carbohydr Polym ; 101: 256-64, 2014 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-24299772

RESUMO

In order to better understand the thermal stability of spent coffee grounds (SCG) galactomannans and arabinogalactans and the reactions that can occur upon roasting, long term isothermal exposures, up to 3h, were performed at 160, 180, 200, 220, and 240 °C. The resultant products were analysed according to the sugars and linkage composition and also by electrospray mass spectrometry. Galactomannans did not loss mass at T ≤ 200 °C during exposures up to 3h whereas the arabinogalactans showed that thermal stability only for T ≤ 180 °C. This was in accordance with the estimated activation energies of their thermal decomposition of 138 kJ/mol and 94 kJ/mol, respectively. The roasting of galactomannans promoted the formation of new glycosidic linkages, with occurrence of 2-, 6-, 2,3-, 2,6-, 3,6-, 2,3,6-, 3,4,6-linked mannose residues, 3,4,6-linked galactose residues, and terminally-linked glucose residues, observed by methylation analysis. Depolymerisation and formation of anhydrohexose residues at the reducing end and mannose-glucose isomerisation were also observed. The roasting of galactomannans at 200 °C promoted their solubility in water upon alkali extraction and neutralisation.


Assuntos
Café/química , Manipulação de Alimentos , Galactanos/química , Mananas/química , Temperatura , Estabilidade de Medicamentos , Galactose/análogos & derivados , Solubilidade , Água/química
17.
Food Chem ; 138(4): 2291-9, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23497888

RESUMO

Thermal processing can promote reactions that change the structure of food constituents, often by unknown mechanisms, such as those occurring in arabinose residues of coffee arabinogalactan side chains. Aiming to know more about these modifications, the structurally related α-(1→5)-l-arabinotriose was roasted at 200°C and the products obtained were identified by ESI-MS and MALDI-MS and characterised by ESI-MS(n). Depolymerised and polymerised oligosaccharides with up to 16 residues and new types of linkages were formed. Also, products resulting from dehydration, oxidation, and cleavage of a carbon-carbon bond at the reducing end of the corresponding non-modified oligosaccharide were formed, probably promoting the release of formaldehyde, formic acid, glycolaldehyde, glyoxal, acetic acid, glycolic acid, glyceraldehyde, 2-hydroxypropanedialdehyde and lactic acid. As many of these compounds have been reported to occur in roasted coffee beans and/or brews, it can be suggested that the degradation of coffee arabinogalactan side chains can contribute to their formation upon roasting.


Assuntos
Arabinose/química , Coffea/química , Café/química , Galactanos/química , Culinária , Temperatura Alta , Modelos Químicos , Estrutura Molecular
18.
Eur J Mass Spectrom (Chichester) ; 18(4): 399-406, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22971700

RESUMO

In this work, biosurfactants produced by two Pseudomonas aeruginosa strains isolated from Brazilian crude oils were identified by proton nuclear magnetic resonance ((1)H NMR) and further characterized by mass spectrometry (MS) coupled with electrospray ionization (ESI) and tandem mass spectrometry (MS/MS) analysis in positive mode and their surface activities evaluated. Mono-rhamnolipids and di-rhamnolipids were identified for both isolates, but the most abundant were found to be mono-rhamnolipids. The similarity of rhamnolipids produced by the two strains was in good agreement with their surface activities. Both biosurfactants exhibited similar aqueous solution surface tensions, high emulsification indexes and critical micelle concentration values. The results obtained show that ESI-MS and MS/MS analysis alone provide a fast and highly specific characterization of biosurfactants produced by microbial strains.


Assuntos
Glicolipídeos/análise , Glicolipídeos/química , Petróleo/microbiologia , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/metabolismo , Espectrometria de Massas em Tandem/métodos , Especificidade da Espécie , Espectrometria de Massas por Ionização por Electrospray
19.
Food Funct ; 3(9): 903-15, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22584883

RESUMO

During the roasting process, coffee bean components undergo structural changes leading to the formation of melanoidins, which are defined as high molecular weight nitrogenous and brown-colored compounds. As coffee brew is one of the main sources of melanoidins in the human diet, their health implications are of great interest. In fact, several biological activities, such as antioxidant, antimicrobial, anticariogenic, anti-inflammatory, antihypertensive, and antiglycative activities, have been attributed to coffee melanoidins. To understand the potential of coffee melanoidin health benefits, it is essential to know their chemical structures. The studies undertaken to date dealing with the structural characterization of coffee melanoidins have shown that polysaccharides, proteins, and chlorogenic acids are involved in coffee melanoidin formation. However, exact structures of coffee melanoidins and mechanisms involved in their formation are far to be elucidated. This paper systematizes the available information and provides a critical overview of the knowledge obtained so far about the structure of coffee melanoidins, mechanisms of their formation, and their potential health implications.


Assuntos
Antioxidantes/química , Café/química , Polímeros/química , Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/análise , Anti-Inflamatórios/farmacologia , Anticarcinógenos/análise , Anticarcinógenos/farmacologia , Anti-Hipertensivos/análise , Anti-Hipertensivos/farmacologia , Antioxidantes/análise , Ácido Clorogênico/análise , Ácido Clorogênico/metabolismo , Colo/efeitos dos fármacos , Colo/microbiologia , Dieta , Humanos , Reação de Maillard , Metaloproteinases da Matriz/metabolismo , Nitrogênio/análise , Nitrogênio/metabolismo , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Polímeros/análise , Polissacarídeos/análise , Polissacarídeos/metabolismo
20.
J Agric Food Chem ; 59(17): 9386-93, 2011 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-21761864

RESUMO

High-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) and tandem mass spectrometry (MS(n)) were used to investigate the phenolic constituents in methanol, water, and methanol/water extracts of Eucalyptus globulus Labill. bark. Twenty-nine phenolic compounds were identified, 16 of them referenced for the first time as constituents of E. globulus bark, namely, quinic, dihydroxyphenylacetic, and caffeic acids, bis(hexahydroxydiphenoyl (HHDP))-glucose, galloyl-bis(HHDP)-glucose, galloyl-HHDP-glucose, isorhamentin-hexoside, quercetin-hexoside, methylellagic acid (EA)-pentose conjugate, myricetin-rhamnoside, isorhamnetin-rhamnoside, mearnsetin, phloridzin, mearnsetin-hexoside, luteolin, and a proanthocyanidin B-type dimer. Digalloylglucose was identified as the major compound in the methanol and methanol/water extracts, followed by isorhamnetin-rhamnoside in the methanol extract and by catechin in the methanol/water extract, whereas in the water extract catechin and galloyl- HHDP-glucose were identified as the predominant components. The methanol/water extract was shown be the most efficient to isolate phenolic compounds identified in E. globulus bark.


Assuntos
Cromatografia Líquida de Alta Pressão , Eucalyptus , Espectrometria de Massas , Fenóis/análise , Casca de Planta/química , Extratos Vegetais/química , Flavonoides/análise , Metanol , Água
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