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1.
Sci Rep ; 11(1): 12692, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135417

RESUMO

When wetted, Plantago seeds become covered with a polysaccharide-rich gel called mucilage that has value as a food additive and bulking dietary fibre. Industrially, the dry husk layer that becomes mucilage, called psyllium, is milled off Plantago ovata seeds, the only commercial-relevant Plantago species, while the residual inner seed tissues are either used for low value animal feed or discarded. We suggest that this practice is potentially wasting a highly nutritious resource and here describe the use of histological, physicochemical, and chromatographic analyses to compare whole seed composition/characteristics of P. ovata with 11 relatives already adapted to harsh Australian conditions that may represent novel commercial crop options. We show that substantial interspecific differences in mucilage yield and macromolecular properties are mainly a consequence of differences in heteroxylan and pectin composition and probably represent wide differences in hydrocolloid functionality that can be exploited in industry. We also show that non-mucilage producing inner seed tissues contain a substantial mannan-rich endosperm, high in fermentable sugars, protein, and fats. Whole seed Plantago flour, particularly from some species obtained from harsh Australian environments, may provide improved economic and health benefits compared to purified P. ovata psyllium husk, by retaining the functionality of the seed mucilage and providing additional essential nutrients.


Assuntos
Alimento Funcional , Plantago/química , Austrália , Fibras na Dieta/análise , Endosperma/anatomia & histologia , Endosperma/química , Lipídeos/análise , Valor Nutritivo , Filogenia , Mucilagem Vegetal/análise , Mucilagem Vegetal/química , Proteínas de Plantas/análise , Plantago/genética , Polissacarídeos/análise , Sementes , Açúcares/análise
2.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1609-1617, Sept.-Oct. 2020. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1131567

RESUMO

The aim of this study was to evaluate the effects of Psyllium (PSY) and Carboxymethylcellulose (CMC) administration on fecal elimination of sand in horses with asymptomatic sand accumulations. Eight horses were selected from sandy areas and randomly divided into 2 groups of four animals. The subjects were treated either with CMC or PSY. The presence of intestinal sand was confirmed through radiography and glove sedimentation test. The study was performed in two phases, with a 7-day interval. In phase I, all the animals received 8 liters of warm water; in phase II, the CMC group received 8 liters of water + 1g/kg of CMC, whereas the PSY group received 8 liters of water + 1g/kg of PSY. All administrations were performed through nasogastric intubation and fractionated in 2 equal volume administrations with an interval of two hours. General and specific physical examination of the digestive system were performed in conjunction with abdominal ultrasonography before the administrations and after 6, 12, 24, 36 and 48 hours, aiming to evaluate intestinal motility and presence of sand. All the feces eliminated by the animals within the 72 hours following the administrations were quantified, diluted and sedimented in order to calculate the sand output (g/kg of feces). All the animals were also subjected to radiographic examination to quantify sand accumulation prior to phase I and after 72 hours of phases I and II. No adverse effects were observed after the treatments. It was possible to notice higher sand elimination in both groups during the phase I, whereas no difference was observed in sand elimination rates between the groups in phase II. The radiographic scores presented differences between the initial timepoint and 72h in phases I and II for both groups. Based on the sand elimination rates and radiographic score, this study demonstrated that sand output was greater after administration of water alone, compared to CMC and Psyllium, leading to the inference that removal of the sandy environment and prevention of sand re-ingestion are effective measures for the elimination of sand from the colon of horses with asymptomatic sand accumulations.(AU)


O objetivo deste estudo foi avaliar os efeitos da administração do psyllium (PSY) e da carboximetilcelulose (CMC) sobre a eliminação fecal de areia em equinos com sablose assintomática. Oito equinos com confirmação radiográfica de sablose assintomática foram divididos em dois grupos (grupo CMC e grupo PSY). O estudo foi realizado em duas fases, com intervalo de sete dias. Na fase 1, todos os animais receberam 8L de água; na fase 2, o grupo CMC recebeu 8L de água + 1g/kg de CMC e o grupo PSY recebeu 8L de água + 1g/kg de PSY. Antes da administração de cada solução e após seis, 12, 24, 36 e 48 horas, foram realizados exame físico e ultrassonografia abdominal. Todas as fezes eliminadas em 72 horas foram avaliadas para quantificar a eliminação de areia (g/kg de fezes). Antes da fase 1 e após 72 horas das fases 1 e 2, o exame radiográfico foi realizado para quantificar o escore de acúmulo de areia. Houve maior eliminação de areia após a administração de água em comparação com a administração de CMC, e não se observou diferença entre a CMC e o PSY. Uma redução significativa nos escores radiográficos de acúmulo de areia foi observada após a administração de água, bem como a manutenção dos escores após a administração da CMC e do PSY. Com base na produção de areia e no escore radiográfico, este estudo sugere que a remoção do ambiente arenoso, impedindo a reingestão de areia, é uma medida eficaz para a eliminação da areia do cólon de cavalos com acúmulos de areia assintomáticos.(AU)


Assuntos
Animais , Psyllium/uso terapêutico , Carboximetilcelulose Sódica/uso terapêutico , Mucilagem Vegetal/análise , Conteúdo Gastrointestinal/diagnóstico por imagem , Areia , Cavalos , Radiografia Abdominal/veterinária
3.
Methods Mol Biol ; 2149: 383-402, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32617947

RESUMO

Arabinogalactan proteins (AGPs) are important plant proteoglycans involved in many development processes. In roots, AGPs occur in the cell wall of root cells and root cap-derived cells as well as in the secreted mucilage. Detection, localization , and quantification techniques are therefore essential to unravel the AGP diversity of structures and functions. This chapter details root-adapted immunocytochemical methods using monoclonal antibodies, and a collection of biochemical analysis protocols using ß-D-glucosyl Yariv reagent for comprehensive AGP characterization.


Assuntos
Cromatografia em Gel/métodos , Eletroforese/métodos , Imuno-Histoquímica/métodos , Mucoproteínas/análise , Arabidopsis/química , Parede Celular/química , Glucosídeos/química , Mucoproteínas/química , Floroglucinol/análogos & derivados , Floroglucinol/química , Mucilagem Vegetal/análise , Mucilagem Vegetal/química , Proteínas de Plantas/análise , Proteínas de Plantas/química , Raízes de Plantas/química
4.
Biomed Res Int ; 2020: 4094350, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32596305

RESUMO

Gum and mucilages from natural sources are in recent times increasingly investigated for pharmaceutical applications. Different studies have shown that the gum and mucilage fraction of various species of the genus Grewia were found to be effective viscosity enhancers, stabilizers, disintegrants, suspending agents, gelling agents, bioadhesives, film coating agents, and binders. However, no study has been conducted on the potential use of Grewia ferruginea mucilage (GFM) as a pharmaceutical excipient. Therefore, this study was aimed at characterizing the Grewia ferruginea bark mucilage for its potential use as a pharmaceutical excipient. The mucilage was extracted from the Grewia ferruginea inner stem bark through aqueous extraction, precipitated with 96% ethanol, dried, and powdered. The powdered mucilage was characterized for different physicochemical properties such as powder property, loss on drying, solubility and swelling index, ash value, pH, viscosity, moisture sorption property, microbial load, and acute oral toxicity. According to the results, the percentage yield of the final dried and powdered GFM was found to be 11.96% (w/w). The density and density-related properties of the mucilage showed good powder flow property. The GFM exhibited pseudoplastic flow behavior. Moisture sorption property of GFM revealed its hygroscopic nature, and its solubility and swelling property was increased with temperature. The pH of GFM was near neutral. Microbial load of the mucilage was within the pharmacopoeial limit, and the oral acute toxicity test revealed that the mucilage is safe up to 2000 mg/kg. From the investigations of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as an excipient in pharmaceutical formulations.


Assuntos
Excipientes , Grewia/química , Mucilagem Vegetal , Animais , Comportamento Animal/efeitos dos fármacos , Excipientes/análise , Excipientes/química , Excipientes/toxicidade , Feminino , Concentração de Íons de Hidrogênio , Camundongos , Casca de Planta/química , Extratos Vegetais/química , Mucilagem Vegetal/análise , Mucilagem Vegetal/química , Mucilagem Vegetal/toxicidade , Solubilidade
5.
Molecules ; 25(9)2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32384787

RESUMO

The Opuntia ficus indica (L.) (OFI) is used as a nutritional and pharmaceutical agent in various dietary and value added products. This study underlines the possible use of native prickly pear cladode powder as a functional ingredient for health-promoting food production. To summarise, chemical characterization of polyphenols, minerals and soluble dietary fibre was performed; furthermore, the antioxidant activity and bioaccessibility of polyphenols and minerals were assessed. Eleven compounds between phenolic acids and flavonoids were identified, with piscidic acid and isorhamnetin derivatives being the most abundant. Opuntia's dietary fibre was mainly constituted of mucilage and pectin, and was composed of arabinose, galactose, glucose, mannose, rhamnose, and xylose sugars. The polyphenols' bioaccessibility was very high: piscidic acid at 200%, eucomic and ferulic acids >110% and flavonoids from 89% to 100%. The prickly pear cladode powder is also a source of minerals, as cations (calcium, sodium, potassium and magnesium) and anions (sulphate and chloride), with high magnesium bioaccessibilty (93%). OFI powder showed good capacity of radical scavenging measured by DPPH and ABTS methods, with 740 and 775 µmol Trolox/100 g OFI, respectively. Finally, the presented results allow the consideration of this natural product as a source of several essential nutrients, with a possible use in the food industry as a functional ingredient.


Assuntos
Antioxidantes/análise , Fibras na Dieta/análise , Frutas/química , Micronutrientes/análise , Opuntia/química , Polifenóis/análise , Polissacarídeos/análise , Ânions/análise , Arabinose/análise , Benzotiazóis/química , Disponibilidade Biológica , Compostos de Bifenilo/química , Cátions/análise , Ácidos Cumáricos/análise , Flavonoides/análise , Galactose/análise , Glucose/análise , Hidroxibenzoatos/análise , Manose/análise , Minerais/análise , Pectinas/análise , Pectinas/isolamento & purificação , Picratos/química , Mucilagem Vegetal/análise , Mucilagem Vegetal/isolamento & purificação , Ramnose/análise , Ácidos Sulfônicos/química , Xilose/análise
6.
Food Chem ; 311: 126039, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31869644

RESUMO

The physical properties of the mucilage polysaccharides of Dioscorea opposita (DOMP) were investigated in this study. The monosaccharide and amino acid contents, and molecular weight were determined, and morphology was observed. The rheological and emulsifying properties of different concentrations of DOMP were determined at acidic and basic pH (pH 5.0 and 9.0). The glucose and protein contents were 11.05% and 13.39%, respectively, and the average molecular weight was 9062 Da. The DOMP particles were spheres of 0.18 µm diameter, which aggregated in solution. The viscosity of DOMP decreased gradually with increase in shear rate, which was indicative of pseudoplastic characteristics. DOMP showed relatively better emulsification properties than Konjac glucomannan (KGM). The particle size of DOMP decreased and its emulsifying properties improved under both acidic and basic conditions. These results suggested that DOMP can be used as a natural processing agent for improving the mouth-feel of food.


Assuntos
Aminoácidos/análise , Dioscorea/química , Mucilagem Vegetal/análise , Polissacarídeos/análise , Emulsificantes/análise , Manipulação de Alimentos , Humanos , Peso Molecular , Monossacarídeos/análise , Tamanho da Partícula , Reologia , Viscosidade
7.
Int J Biol Macromol ; 131: 218-229, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30872053

RESUMO

The rheological behavior, thermogravimetric analysis (TGA), and atomic force microscopy (AFM) of the Pereskia aculeata Miller (OPN) mucilage treated with sodium chloride (NaCl), calcium chloride (CaCl2), and sucrose were evaluated. The experimental design was divided in a fractional factorial 25-1 for the screening of factors (OPN, sucrose, NaCl, CaCl2, and pH) and then in a 5 × 3 × 3 full factorial (OPN, sucrose, and NaCl). The model solutions used for the screening of factors presented shear-thinning behavior and the OPN mucilage concentrations were the factors that had significant effect on the apparent viscosity. Sucrose addition increased the thermal stability of the OPN mucilage solutions. OPN mucilage, sucrose, and NaCl were the variables with significant effect on thermogravimetric responses. The samples presented Newtonian behavior in 0-1.25% OPN mucilage concentrations and non-Newtonian behavior adjusted by power-law in 2.50-5.00% OPN mucilage concentrations with predominance of elastic behavior, contributing to the formation of stronger gels. The presence of sucrose in the systems containing OPN mucilage changed their rheological properties and salt additions caused reduction in viscosity. The AFM results provided a better understanding of the mechanism of OPN mucilage interactions in different solutions that justify the changes in viscosities.


Assuntos
Mucilagem Vegetal/química , Reologia , Sais/química , Estreptófitas/química , Sacarose/química , Microscopia de Força Atômica , Estrutura Molecular , Mucilagem Vegetal/análise , Cloreto de Sódio/química , Temperatura , Termogravimetria
8.
Food Chem ; 245: 13-21, 2018 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-29287353

RESUMO

The mucilage polysaccharides from Dioscorea opposita (DOMP) were extracted and treated with a single/dual enzymatic hydrolysis. The characterisation and viscosity were subsequently investigated in this study. DOMP obtained 62.52% mannose and 23.45% glucose. After single protease and trichloroacetic acid (TCA) treatments, the mannose content was significantly reduced to 3.96%, and glucose increased from 23.45% to 45.10%. Dual enzymatic hydrolysis also decreased the mannose and glucose contents to approximately 18%-35% and 7%-19%, respectively. The results suggest that enzymatic degradation could effectively remove the protein from DOMP accompanied by certain polysaccharides, especially mannose. The molecular weight, surface morphology, viscosity and particle sizes were measured. Enzymatic hydrolysis reduced molecular weight, decreased the viscosity, and increased the particle sizes, which indicates that the characterisations of DOMP samples were altered as structures changed. This study was a basic investigation into characterisation of DOMP to contribute to the processing of food by-products.


Assuntos
Dioscorea/química , Enzimas/química , Mucilagem Vegetal/química , Glucose/análise , Hidrólise , Manose/análise , Peso Molecular , Mucilagem Vegetal/análise , Proteínas de Plantas/química , Viscosidade
9.
J Agric Food Chem ; 65(12): 2572-2579, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28267913

RESUMO

Chia (Salvia hispanica L.) seeds contain an important amount of edible oil rich in omega-3 fatty acids. Fast and alternative extraction techniques based on polar solvents, such as ethanol or water, have become relevant for oil extraction in recent years. However, chia seeds also contain a large amount of soluble fiber or mucilage, which makes difficult an oil extraction process with polar solvents. For that reason, the aim of this study was to develop a gentle extraction method for mucilage in order to extract chia oil with polar solvents using pressurized liquids and compare with organic solvent extraction. The proposed mucilage extraction method, using an ultrasonic probe and only water, was optimized at mild conditions (50 °C and sonication 3 min) to guarantee the omega-3 oil quality. Chia oil extraction was performed using pressurized liquid extraction (PLE) with different solvents and their mixtures at five different extraction temperatures (60, 90, 120, 150, and 200 °C). Optimal PLE conditions were achieved with ethyl acetate or hexane at 90 °C in only 10 min of static extraction time (chia oil yield up to 30.93%). In addition, chia oils extracted with nonpolar and polar solvents by PLE were analyzed by gas chromatography-mass spectrometry (GC-MS) to evaluate fatty acid composition at different extraction conditions. Chia oil contained ∼65% of α-linolenic acid regardless of mucilage extraction method, solvent, or temperature used. Furthermore, tocopherols and tocotrienols were also analyzed by HPLC in the extracted chia oils. The mucilage removal allowed the subsequent extraction of the chia oil with polar or nonpolar solvents by PLE producing chia oil with the same fatty acid and tocopherol composition as traditional extraction.


Assuntos
Fracionamento Químico/métodos , Ácidos Graxos Ômega-3/química , Mucilagem Vegetal/isolamento & purificação , Óleos de Plantas/química , Salvia/química , Sementes/química , Ultrassom/métodos , Fracionamento Químico/instrumentação , Ácidos Graxos Ômega-3/isolamento & purificação , Mucilagem Vegetal/análise , Óleos de Plantas/isolamento & purificação , Ultrassom/instrumentação
10.
J Exp Bot ; 67(22): 6481-6495, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27856710

RESUMO

Xylans are the most abundant non-cellulosic polysaccharide found in plant cell walls. A diverse range of xylan structures influence tissue function during growth and development. Despite the abundance of xylans in nature, details of the genes and biochemical pathways controlling their biosynthesis are lacking. In this study we have utilized natural variation within the Plantago genus to examine variation in heteroxylan composition and structure in seed coat mucilage. Compositional assays were combined with analysis of the glycosyltransferase family 61 (GT61) family during seed coat development, with the aim of identifying GT61 sequences participating in xylan backbone substitution. The results reveal natural variation in heteroxylan content and structure, particularly in P. ovata and P. cunninghamii, species which show a similar amount of heteroxylan but different backbone substitution profiles. Analysis of the GT61 family identified specific sequences co-expressed with IRREGULAR XYLEM 10 genes, which encode putative xylan synthases, revealing a close temporal association between xylan synthesis and substitution. Moreover, in P. ovata, several abundant GT61 sequences appear to lack orthologues in P. cunninghamii. Our results indicate that natural variation in Plantago species can be exploited to reveal novel details of seed coat development and polysaccharide biosynthetic pathways.


Assuntos
Glicosiltransferases/metabolismo , Mucilagem Vegetal/metabolismo , Plantago/fisiologia , Sementes/fisiologia , Glicosiltransferases/genética , Microscopia , Microscopia Eletrônica de Varredura , Filogenia , Mucilagem Vegetal/análise , Plantago/enzimologia , Plantago/genética , Plantago/metabolismo , Reação em Cadeia da Polimerase , Sementes/química , Sementes/enzimologia , Sementes/crescimento & desenvolvimento
11.
Cytometry A ; 85(10): 833-40, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24853918

RESUMO

The family Hyacinthaceae constitutes about 900 species of bulbous geophytes usually characterized by high mucilage content. Taxonomic delimitation of Hyacinthaceae has been controversial since the time of Linnaeus due to the absence of reliable discriminating characters. Pattern of genome size variation can thus be considered as an added character to aid intergeneric and intrageneric relationship of the group. However, reports on genome size estimation by flow cytometric analysis of these plants are rare due to the presence of mucilage, which causes problem with nuclei sample preparation. To overcome this problem five reported nuclei isolation buffers were tested in Drimia indica of which Galbraith's buffer gave comparatively better results and was further modified by increasing pH, detergent concentration, and replacing sodium citrate by citric acid. The modified buffer enabled better sample preparation with increased yield, lesser debris, and improved DNA peak CV. The standardized buffer was used to estimate the 2C values of Drimia indica, Drimia nagarjunae, Drimia wightii, Drimia coromandeliana, and Ledebouria revoluta for the first time by flow cytometric analysis. This study also opens up the scope for further improvement in sample preparation for flow cytometric analysis of mucilaginous plants, which is otherwise problematic due to nuclei clumping and increased viscosity of sample.


Assuntos
DNA de Plantas/genética , Citometria de Fluxo/métodos , Tamanho do Genoma/genética , Liliaceae/genética , Mucilagem Vegetal/genética , Mucilagem Vegetal/análise , Raízes de Plantas/genética , Especificidade da Espécie
12.
Braz. j. pharm. sci ; 50(4): 713-725, Oct-Dec/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-741364

RESUMO

Mucilage was isolated from the seeds of Diospyros melonoxylon Roxb., a plant growing naturally in the forests of India. Various physico-chemical methods like particle analysis, scanning electron microscopy, differential scanning calorimetry, differential thermal analysis, thermogravimetry analysis, molecular weight by gel permeation chromatography, rheometry, elemental analysis, x-ray diffraction spectrometry, zeta potential, fourier transform infrared spectroscopy, 1D(1H and 13C) (NMR) have been employed to characterize this gum in the present study. Particle analyses suggest that mucilage had particle size in nanometer. SEM analysis suggested that the mucilage had irregular particle size. The glass transition temperature of the gum observed was 78 °C and 74 °C by DSC and DTA respectively. The Thermogravimetry analysis suggested that mucilage had good thermal stability with two stage decomposition. The molecular weight of mucilage was determined to be 8760, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The XRD pattern of the mucilage indicated a complete amorphous nature. Elemental analysis of the gum revealed specific contents of carbon, hydrogen, nitrogen and sulfur. The major functional groups identified from FT-IR spectrum include 3441 cm-1 (-OH), 1632 cm-1 (-COO-), 1414 cm-1 (-COO-) and 1219 cm-1 (-CH3CO). Analysis of mucilage by paper chromatography and 1D NMR indicated the presence of sugars.


Mucilagem foi isolada de sementes de Diospyros melanoxylon Roxb, uma planta que cresce naturalmente nas florestas da Índia. Vários métodos físico-químicos, como análise de partículas, microscopia electrônica, calorimetria diferencial de varredura, análise térmica diferencial, análise termogravimétrica, massa molecular por cromatografia de permeação em gel, viscosidade, análise elementar, espectrometria de difração de raios-x, potencial zeta, espectroscopia no infravermelho com transformada de Fourier, 1D (1H e 13C) (NMR) foram utilizados no presente estudo para caracterizar essa goma. A análise de partículas sugere que a mucilagem tem tamanho de partícula em nm. A análise SEM sugere que a mucilagem tem tamanho de partícula irregular. Observou-se temperatura de transição vítrea da goma de 78 °C e 74 °C por DSC e DTA, respectivamente. A análise termogravimétrica sugeriu que a mucilagem possuía boa estabilidade térmica, com duas fases de decomposição. A massa molecular da mucilagem foi 8760, por meio de cromatografia de permeação em gel, enquanto que a viscosidade foi 219,1 cP. O padrão de DRX da mucilagem indicou natureza completamente amorfa. Os principais grupos funcionais identificados a partir do espectro de FT-IR foram: 3441 cm-1 (-OH), 1632 cm-1 (-COO-), 1414 cm-1 (-COO-) e 1.219 cm-1 (CH3CO-). As análises de mucilagem por cromatografia em papel e 1D RMN indicaram a presença de açúcares.


Assuntos
/análise , Diospyros , Mucilagem Vegetal/análise , Potencial zeta/classificação , Espectroscopia de Infravermelho com Transformada de Fourier , Diospyros/classificação
13.
Plant Physiol ; 163(3): 1203-17, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24092888

RESUMO

The function of a putative galacturonosyltransferase from Arabidopsis (Arabidopsis thaliana; At1g02720; GALACTURONOSYLTRANSFERASE-LIKE5 [AtGATL5]) was studied using a combination of molecular genetic, chemical, and immunological approaches. AtGATL5 is expressed in all plant tissues, with highest expression levels in siliques 7 DPA. Furthermore, its expression is positively regulated by several transcription factors that are known to regulate seed coat mucilage production. AtGATL5 is localized in both endoplasmic reticulum and Golgi, in comparison with marker proteins resident to these subcellular compartments. A transfer DNA insertion in the AtGATL5 gene generates seed coat epidermal cell defects both in mucilage synthesis and cell adhesion. Transformation of atgatl5-1 mutants with the wild-type AtGATL5 gene results in the complementation of all morphological phenotypes. Compositional analyses of the mucilage isolated from the atgatl5-1 mutant demonstrated that galacturonic acid and rhamnose contents are decreased significantly in atgatl5-1 compared with wild-type mucilage. No changes in structure were observed between soluble mucilage isolated from wild-type and mutant seeds, except that the molecular weight of the mutant mucilage increased 63% compared with that of the wild type. These data provide evidence that AtGATL5 might function in the regulation of the final size of the mucilage rhamnogalacturonan I.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Mucilagem Vegetal/metabolismo , Sementes/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Complexo de Golgi/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Ácidos Hexurônicos/metabolismo , Hibridização In Situ , Microscopia Confocal , Microscopia Eletrônica de Varredura , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Pectinas/metabolismo , Mucilagem Vegetal/análise , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ramnose/metabolismo , Sementes/genética , Sementes/ultraestrutura , Transcriptoma
14.
Carbohydr Polym ; 93(2): 651-60, 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23499108

RESUMO

The present study aimed at analyzing the structural features of seed mucilage and cell-wall polysaccharides which accounted for 41% of the mass of flax meal (FM). A combination of high molar-mass mucilage-like polysaccharides (rhamnogalacturonan and arabinoxylan) was released from FM in water, together with arabinogalactan proteins and glucans. About half of FM homogalacturonans was extracted using a calcium chelator and boiling water. Hemicellulosic xyloglucans and xylans were further extracted with 1M KOH, in ∼13% FM-sugars yield. Structural characterization of the xyloglucan using specific enzyme hydrolysis, ion exchange chromatography (HPAEC) and matrix assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectroscopy showed the presence of XXXG type xyloglucan, but also that of XXGG-structure, possibly characteristic of flax seeds. Hydrolysis of xylans with endo-(1→4)-ß-D-xylanase, and analysis of the neutral and acidic oligosaccharides by MALDI-TOF-MS showed that xylan consisted of ß-(1→4)-linked-D-xylopyranose backbone with some zones (DP 5-7) substituted with 4-O-MeGlcA\GlcA\Glc residues.


Assuntos
Parede Celular/química , Linho/química , Mucoproteínas/análise , Mucilagem Vegetal/análise , Polissacarídeos/análise , Sementes/química , Quelantes/química , Hidrólise , Mucoproteínas/química , Pectinas/química , Mucilagem Vegetal/química , Proteínas de Plantas/análise , Proteínas de Plantas/química , Polissacarídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Ácidos Urônicos/química , Água/química , Xilanos/química
15.
Plant Cell ; 25(1): 308-23, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23362209

RESUMO

Imbibed seeds of the Arabidopsis thaliana accession Djarly are affected in mucilage release from seed coat epidermal cells. The impaired locus was identified as a pectin methylesterase inhibitor gene, PECTIN METHYLESTERASE INHIBITOR6 (PMEI6), specifically expressed in seed coat epidermal cells at the time when mucilage polysaccharides are accumulated. This spatio-temporal regulation appears to be modulated by GLABRA2 and LEUNIG HOMOLOG/MUCILAGE MODIFIED1, as expression of PMEI6 is reduced in mutants of these transcription regulators. In pmei6, mucilage release was delayed and outer cell walls of epidermal cells did not fragment. Pectin methylesterases (PMEs) demethylate homogalacturonan (HG), and the majority of HG found in wild-type mucilage was in fact derived from outer cell wall fragments. This correlated with the absence of methylesterified HG labeling in pmei6, whereas transgenic plants expressing the PMEI6 coding sequence under the control of the 35S promoter had increased labeling of cell wall fragments. Activity tests on seeds from pmei6 and 35S:PMEI6 transgenic plants showed that PMEI6 inhibits endogenous PME activities, in agreement with reduced overall methylesterification of mucilage fractions and demucilaged seeds. Another regulator of PME activity in seed coat epidermal cells, the subtilisin-like Ser protease SBT1.7, acts on different PMEs, as a pmei6 sbt1.7 mutant showed an additive phenotype.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/enzimologia , Pectinas/metabolismo , Epiderme Vegetal/enzimologia , Mucilagem Vegetal/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Parede Celular/metabolismo , Esterificação , Metilação , Mutação , Pectinas/análise , Fenótipo , Epiderme Vegetal/genética , Mucilagem Vegetal/análise , Plantas Geneticamente Modificadas , Sementes/enzimologia , Sementes/genética , Subtilisinas/genética , Subtilisinas/metabolismo
16.
Chem Biodivers ; 9(8): 1599-610, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22899620

RESUMO

The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or 'xoconostle') had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber.


Assuntos
Fibras na Dieta/análise , Frutas/química , Opuntia/química , Polissacarídeos/análise , Celulose/análise , Pectinas/análise , Mucilagem Vegetal/análise
17.
Arch. latinoam. nutr ; 62(2): 192-200, jun. 2012. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-710622

RESUMO

En los últimos años se ha promovido el consumo de linaza (Linum usitatissimum L.) como alimento funcional por sus beneficios a la salud, atribuibles principalmente a su contenido de ácidos grasos omega-3, lignanos, y fibra dietaria. En este estudio se evaluó la calidad microbiológica, composición química y las propiedades antioxidantes de la semilla de linaza cultivada en Venezuela y se comparó con una variedad canadiense de amplia venta en el país. Se determinaron coliformes totales, mohos y levaduras, S. aureus, y esporulados de los géneros Bacillus (aerobios) y Clostridium (anaerobios), humedad, grasas, proteínas, fibra dietética total, soluble e insoluble, mucílago, minerales, perfil de ácidos grasos, contenido de HCN equivalente, aw, color, polifenoles y propiedades antioxidantes como Eficiencia Antirradical (EA), concentración de antioxidante necesario para disminuir la concentración inicial en 50 % (EC50) y el tiempo necesario para alcanzar la EC50 (TEC50). Se determinaron diferencias significativas en la composición de las semillas, resaltando su elevado contenido de grasa, proteínas, ácido alfa-linolénico y fibra dietaria. Se observaron diferencias en el contenido de mucílago, pero no en el de fibra soluble, insoluble y total. La concentración de HCN equivalente en ambas semillas es del orden de 40 mg/100 g, lo cual no representa riesgos a la salud, si se consideran sus formas de consumo. La linaza venezolana contiene mayor contenido de polifenoles que la canadiense, pero la capacidad antioxidante de esta última es mayor; ambas tienen una EA calificada como media (TEC50>30 min).


Characterization of flaxseed (Linum usitatissimum L.) grown in Venezuela. In recent years, the consumption of flaxseed (Linum usitatissimum L.) has been promoted as a functional food for its health benefits, mainly attributable to its content of omega-3 fatty acids, lignans and dietary fiber. This study evaluated the microbiological quality, chemical composition and antioxidant properties of flaxseed grown in Venezuela and compared them to the values of a Canadian variety widely sold in the country. Total coliforms, molds and yeasts, S. aureus and sporulated of the genera Bacillus (aerobic) and Clostridium (anaerobic), moisture, fat, protein, total dietary fiber, soluble and insoluble, mucilage, minerals, fatty acid profile, equivalent HCN content, aw, color, polyphenols and antioxidant properties, like antiradical efficiency (AE), concentration of antioxidant needed to decrease the initial concentration by 50 % (EC50) and the time required to reach the EC50 (TEC50) were evaluated. Significant differences in seed composition were determined, where its high content of fat, protein, alfalinolenic acid and dietary fiber stand out. Differences were observed in the mucilage content, but not in soluble, insoluble and total fiber content. Equivalent HCN concentration in both seeds is in the order of 40 mg/100 g, which poses no health risks, considering their consumption patterns. Venezuelan flaxseed contains higher content of polyphenols than the Canadian does, but the antioxidant capacity of the latter is higher; both have an EA rated as average and a slow reaction time (TEC50> 30 min).


Assuntos
Antioxidantes/análise , Linho/química , Polifenóis/análise , Sementes/química , Canadá , Microbiologia de Alimentos , Alimento Funcional , Linho/microbiologia , Cianeto de Hidrogênio/análise , Mucilagem Vegetal/análise , Sementes/microbiologia , Venezuela
18.
Arch Latinoam Nutr ; 62(2): 192-200, 2012 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-23610908

RESUMO

In recent years, the consumption of flaxseed (Linum usitatissimum L.) has been promoted as a functional food for its health benefits, mainly attributable to its content of omega-3 fatty acids, lignans and dietary fiber. This study evaluated the microbiological quality, chemical composition and antioxidant properties of flaxseed grown in Venezuela and compared them to the values of a Canadian variety widely sold in the country. Total coliforms, molds and yeasts, S. aureus and sporulated of the genera Bacillus (aerobic) and Clostridium (anaerobic), moisture, fat, protein, total dietary fiber, soluble and insoluble, mucilage, minerals, fatty acid profile, equivalent HCN content, aw, color, polyphenols and antioxidant properties, like antiradical efficiency (AE), concentration of antioxidant needed to decrease the initial concentration by 50 %EC50) and the time required to reach the EC50 (TEC50) were evaluated. Significant differences in seed composition were determined, where its high content of fat, protein, alfa-linolenic acid and dietary fiber stand out. Differences were observed in the mucilage content, but not in soluble, insoluble and total fiber content. Equivalent HCN concentration in both seeds is in the order of 40 mg/100 g, which poses no health risks, considering their consumption patterns. Venezuelan flaxseed contains higher content of polyphenols than the Canadian does, but the antioxidant capacity of the latter is higher; both have an EA rated as average and a slow reaction time (TEC50 > 30 min).


Assuntos
Antioxidantes/análise , Linho/química , Polifenóis/análise , Sementes/química , Canadá , Linho/microbiologia , Microbiologia de Alimentos , Alimento Funcional , Cianeto de Hidrogênio/análise , Mucilagem Vegetal/análise , Sementes/microbiologia , Venezuela
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