pectins has been researched along with ferulic-acid* in 23 studies
1 review(s) available for pectins and ferulic-acid
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Fabrication and biomedical applications of Arabinoxylan, Pectin, Chitosan, soy protein, and silk fibroin hydrogels via laccase - Ferulic acid redox chemistry.
The unique physiochemical properties and the porous network architecture of hydrogel seek the attention to be explored in broad range of fields. In the last decade, numerous studies on the development of enzymatically cross-linked hydrogels have been elucidated. Implementing enzyme based cross-linking for fabrication of biomaterials over other cross-linking methods harbor various advantages, especially hydrogels designed using laccase exhibits mild reaction environment, high cross-linking efficiency and less toxicity. To our knowledge this is the first report reviewing the formulation of laccase mediated cross-linking for hydrogel preparation. Here, laccase catalyzed synthesis of hydrogel using polysaccharide viz. arabinoxylan, sugar beet pectin, galactomannan, chitosan etc. and proteins namely soy protein, gelatin, silk fibroin were discussed on highlighting their mechanical properties and its possible field of application. We have summarized the role of phenolic acids in laccase mediated cross-linking particularly ferulic acid which is a component of lignocellulose, serving cell rigidity via cross-linkage. The review also discusses on various biomedical applications such as controlled protein release, tissue engineering, and wound healing. It is anticipated that this review will give a detailed information on different laccase mediated reaction strategies that can be applied for the synthesis of various new biomaterials with tailor made properties. Topics: Chitosan; Coumaric Acids; Fibroins; Hydrogels; Laccase; Oxidation-Reduction; Pectins; Silk; Soybean Proteins; Xylans | 2022 |
22 other study(ies) available for pectins and ferulic-acid
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Ferulic acid- and gallic ester-acylated pectin: Preparation and characterization.
In this study, pectin was modified with ferulic acid (Fa), trans-ferulic acid (trans-Fa), methyl gallate (MG), and ethyl gallate (EG) via the enzymatic method using aqueous/organic phases to enhance its physiochemical and bio-active properties. Results revealed that lipase might catalyze the hydrolysis of the ester bond within pectin in aqueous phase and prompt the transesterification between the hydroxyl group in the para position in Fa/trans-Fa or the 2'-OH group of MG/EG and the carboxylic group of pectin in the organic phase. The graft ratio was 21.00%, 21.67%, 13.24%, and 11.93% for the Fa-, trans-Fa-, MG-, and EG-modified pectin, respectively. In addition, compared with native pectin, the modified pectin exhibited improved apparent viscosity and emulsion activity. Moreover, the clearance of 1,1-diphenyl-2-picryl hydrazine (DPPH) and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) was effectively enhanced for the modified pectin. Furthermore, the modified pectin exhibited strong antibacterial activity against Escherichia coli and Staphylococcus aureus while no cytotoxic effects based on the results of cell culture experiments. Our results provide a theoretical basis for the expansion of pectin applications in the food and pharmaceutical industries. Topics: Antioxidants; Coumaric Acids; Escherichia coli; Esters; Gallic Acid; Pectins; Staphylococcus aureus | 2022 |
Physicochemical, Thermal and Rheological Properties of Pectin Extracted from Sugar Beet Pulp Using Subcritical Water Extraction Process.
The objective of this study was to characterize the properties of pectin extracted from sugar beet pulp using subcritical water (SWE) as compared to conventional extraction (CE). The research involved advanced modeling using response surface methodology and optimization of operational parameters. The optimal conditions for maximum yield of pectin for SWE and CE methods were determined by the central composite design. The optimum conditions of CE were the temperature of 90 °C, time of 240 min, pH of 1, and pectin recovery yield of 20.8%. The optimal SWE conditions were liquid-to-solid (L/S) ratio of 30% ( Topics: Acetylation; Beta vulgaris; Chemical Fractionation; Color; Coumaric Acids; Hexuronic Acids; Hydrogen-Ion Concentration; Methylation; Molecular Weight; Pectins; Rheology; Spectroscopy, Fourier Transform Infrared; Starch; Temperature | 2021 |
Characterization of covalent, feruloylated polysaccharide gels by pulsed field gradient-stimulated echo (PFG-STE)-NMR.
Translational mobility of guest molecules such as water and glucose in gels that are based on feruloylated polysaccharides appears to be critical to understand their nutritional and functional properties. Here, the applicability of PFG-STE-NMR on feruloylated gels was proven, and relationships to rheological data were studied. Arabinoxylans and pectins were extracted from by-products using varying conditions. Laccase induced coupling of these chemically characterized polymers resulted for most of the feruloylated polysaccharides in homogeneous gels. Rheological studies confirmed that polysaccharide composition affects viscoelastic properties of the resulting gels. Generally, diffusion of water and glucose is hindered in gels. In the feruloylated polysaccharide gels, both polysaccharide concentration and extraction conditions affect the diffusion behavior of these molecules. A simple correlation between rheological data and mobility of guest molecules has not generally been found: although long time acid extracted pectins form highly elastic gels, water diffusion in these gels is less hindered. Topics: Beta vulgaris; Coumaric Acids; Diffusion; Gels; Glucose; Magnetic Resonance Spectroscopy; Pectins; Viscoelastic Substances; Water; Xylans; Zea mays | 2021 |
Ascorbic acid, sucrose and olive oil lipids mitigate the inhibitory effects of pectin on the bioaccessibility and Caco-2 cellular uptake of ferulic acid and naringenin.
Whole fruit and vegetable consumption is universally promoted as healthy, to a large extent due to their high contents of phytochemicals, including phenolics and dietary fibre. The major fibre in fruits and vegetables, pectin, however also decreases the bioavailability of phenolics and carotenoids. While ascorbic acid, sucrose and olive oil lipids may increase the bioavailability of various phenolics, their effects in the presence of pectin have not been investigated. This study aimed to evaluate the modulating effects of sucrose (5.0%), ascorbic acid (0.1%) and olive oil (2.5%) on the inhibition by pectin (2.0%) of ferulic acid and naringenin bioaccessibility and Caco-2 cellular uptake. Pectin reduced the bioaccessbility of ferulic acid and naringenin, by 45 and 65%, respectively. Sucrose mitigated the inhibitory effect of pectin and increased naringenin bioaccessbility from 7.9 to 15.0%. When added to digestions with ferulic acid and pectin, sucrose and olive oil totally negated pectin's bioaccessibility inhibition. The Caco-2 cellular uptake of bioaccessible ferulic acid was high (58.3%) and pectin and ascorbic acid together increased it to 85.6%. The Caco-2 cellular uptake of bioaccessible naringenin was also high (47.0%) and pectin increased it to 95.0%. Sucrose and olive oil for ferulic acid and only sucrose for naringenin totally negated the inhibitory effect of pectin on the overall in vitro availability (cellular uptake as percentage of amount of phenolic initially digested). The ameliorating effects of sucrose and olive oil are due to substantially increased bioaccessibility of the phenolics, probably due reduced encapsulation of the phenolics in pectin. Topics: Ascorbic Acid; Biological Availability; Biological Transport; Caco-2 Cells; Coumaric Acids; Flavanones; Humans; Lipids; Olive Oil; Pectins; Sucrose | 2020 |
Characterization of Micronutrients, Bioaccessibility and Antioxidant Activity of Prickly Pear Cladodes as Functional Ingredient.
Topics: Anions; Antioxidants; Arabinose; Benzothiazoles; Biological Availability; Biphenyl Compounds; Cations; Coumaric Acids; Dietary Fiber; Flavonoids; Fruit; Galactose; Glucose; Hydroxybenzoates; Mannose; Micronutrients; Minerals; Opuntia; Pectins; Picrates; Plant Mucilage; Polyphenols; Polysaccharides; Rhamnose; Sulfonic Acids; Xylose | 2020 |
Identification and characterization of ferulic acid esterase from Penicillium chrysogenum 31B: de-esterification of ferulic acid decorated with l-arabinofuranoses and d-galactopyranoses in sugar beet pectin.
Topics: Arabinose; Carboxylic Ester Hydrolases; Cloning, Molecular; Coumaric Acids; Enzyme Stability; Galactose; Gene Expression; Hydrogen-Ion Concentration; Pectins; Penicillium chrysogenum; Pichia; Substrate Specificity; Temperature | 2019 |
Downregulation of pectin biosynthesis gene
Knockdown (KD) expression of Topics: Carbohydrate Metabolism; Coumaric Acids; Glucuronosyltransferase; Lignin; Magnetic Resonance Spectroscopy; Panicum; Pectins; Polysaccharides | 2019 |
Preparation and properties of ferulic acid-sugar beet pulp pectin ester and its application as a physical and antioxidative stabilizer in a fish oil-water emulsion.
Topics: Antioxidants; Chemical Phenomena; Coumaric Acids; Emulsions; Esters; Fish Oils; Magnetic Resonance Spectroscopy; Pectins; Spectroscopy, Fourier Transform Infrared; Sugars; Water | 2019 |
Non-covalent interaction between ferulic acid and arabinan-rich pectic polysaccharide from rapeseed meal.
The sorption capacity of arabinan-rich pectic polysaccharide (ARPP) onto ferulic acid (FA) was investigated using equilibrium dialysis assays. UV and FT-IR spectra showed that FA was successfully adsorbed by ARPP. The effects of temperature, pH, buffer concentration, NaCl, and ethanol on sorption were investigated. Sorption variable optimization was examined by response surface methodology. The order of influence of each factor in affecting the sorption capacity was temperature>pH>buffer concentration. The maximum sorption yield was 363.92±18.37μg/mg at 36.8°C, pH 5.26, and a buffer concentration of 0.09M. Langmuir, Freundlich, and Temkin models were used to fit the experimental data under the optimized conditions. The Freundlich model showed the closest fit with an R Topics: Adsorption; Brassica rapa; Coumaric Acids; Ethanol; Hydrogen-Ion Concentration; Osmolar Concentration; Pectins; Polysaccharides; Sodium Chloride; Temperature | 2017 |
Functionalization of pectin with laccase-mediated oxidation products of ferulic acid.
Pectin is a natural biopolymer extracted mostly from citrus peel, sugar beet and apple pomace. In order to improve its functional properties and then to enlarge the field of its potential applications, functionalization reaction of citrus pectin with ferulic acid (FA)-oxidation products was performed in aqueous medium, at 30°C and pH7.5, in the presence of Myceliophthora thermophila laccase as biocatalyst. The conjugation between FA-oxidation products and pectin was confirmed using FTIR, UV-Vis and LC-MS analyses. The obtained results suggested that covalent bonds were between the pectin carboxyl groups and FA-oxidation products between the pectin carboxyl groups and FA-oxidation products. The determination of the total phenolic content showed that the modified pectin contained 5 times more phenols than the native pectin. In view of these results, this enzymatic procedure appears as a promising way to provide new pectin-based polymers that are expected to present new properties of interest. Topics: Ascomycota; Biotechnology; Coumaric Acids; Laccase; Magnetic Resonance Spectroscopy; Oxidation-Reduction; Pectins; Phenols; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry; Spectroscopy, Fourier Transform Infrared | 2017 |
Feruloyl esterases from Schizophyllum commune to treat food industry side-streams.
Agro-industrial side-streams are abundant and renewable resources of hydroxycinnamic acids with potential applications as antioxidants and preservatives in the food, health, cosmetic, and pharmaceutical industries. Feruloyl esterases (FAEs) from Schizophyllum commune were functionally expressed in Pichia pastoris with extracellular activities of 6000UL(-1). The recombinant enzymes, ScFaeD1 and ScFaeD2, released ferulic acid from destarched wheat bran and sugar beet pectin. Overnight incubation of coffee pulp released caffeic (>60%), ferulic (>80%) and p-coumaric acid (100%) indicating applicability for the valorization of food processing wastes and enhanced biomass degradation. Based on substrate specificity profiling and the release of diferulates from destarched wheat bran, the recombinant FAEs were characterized as type D FAEs. ScFaeD1 and ScFaeD2 preferably hydrolyzed feruloylated saccharides with ferulic acid esterified to the O-5 position of arabinose residues and showed an unprecedented ability to hydrolyze benzoic acid esters. Topics: Benzoic Acid; Biotechnology; Carbohydrate Metabolism; Carboxylic Ester Hydrolases; Coffee; Coumaric Acids; Dietary Fiber; Food Industry; Hydrolysis; Industrial Waste; Pectins; Pichia; Propionates; Recombinant Proteins; Schizophyllum; Substrate Specificity | 2016 |
Characterization of diferuloylated pectic polysaccharides from quinoa (Chenopodium quinoa WILLD.).
In plants belonging to the order of Caryophyllales, pectic neutral side chains can be substituted with ferulic acid. The ability of ferulic acid to form intra- and/or intermolecular polysaccharide cross-links by dimerization was shown by the isolation and characterization of diferulic acid oligosaccharides from monocotyledonous plants. In this study, two diferulic acid oligosaccharides were isolated from the enzymatic hydrolyzate of seeds of the dicotyledonous pseudocereal quinoa by gel permeation chromatography and preparative HPLC and unambiguously identified by LC-MS(2) and 1D/2D NMR spectroscopy. The isolated oligosaccharides are comprised of 5-5- and 8-O-4-diferulic acid linked to the O2-position of the nonreducing residue of two (1→5)-linked arabinobioses. To get insight into the structure and the degree of phenolic acid substitution of the diferuloylated polysaccharides, polymeric sugar composition, glycosidic linkages, and polysaccharide-bound monomeric phenolic acids and diferulic acids were analyzed. This study demonstrates that diferulic acids are involved into intramolecular and/or intermolecular cross-linking of arabinan chains and may have a major impact on cell wall architecture of quinoa and other dicotyledonous plants of the order of Caryophyllales. Topics: Bolivia; Cell Wall; Chenopodium quinoa; Cinnamates; Coumaric Acids; Nuclear Magnetic Resonance, Biomolecular; Pectins; Polysaccharides; Seeds | 2015 |
Simple and validated quantitative ¹H NMR method for the determination of methylation, acetylation, and feruloylation degree of pectin.
The knowledge of pectin esterification degree is of primary importance to predict gelling and other properties of pectin from different sources. This paper reports the development of a simple and rapid (1)H NMR-based method for the simultaneous quantitative determination of methylation, acetylation, and feruloylation degree of pectin isolated from various food sources. Pectin esters are hydrolyzed in NaOH/D2O, and the obtained methanol, acetic acid, and ferulic acid are directly measured by (1)H NMR. High accuracy, repeatability, and reproducibility of the method were obtained, and the analysis time is reduced as compared to conventional chromatography- or titration-based methods. Topics: Acetic Acid; Acetylation; Coumaric Acids; Dopamine; Esterification; Hydrolysis; Magnetic Resonance Spectroscopy; Methanol; Methylation; Molecular Structure; Pectins; Reproducibility of Results | 2014 |
Structural features and water holding capacities of pressed potato fibre polysaccharides.
Pressed potato fibre (PPF) has a high water holding capacity (WHC) affecting its processing as an animal feed. The aim of this study was to characterize cell wall polysaccharides (CWPs) in PPF and investigate their WHC. This was done via sequential extractions. Half of all CWPs were recovered in the hot buffer soluble solids extract as pectins (uronic acid and rhamnose) and galactans wherein most pectins (76%) from PPF were water soluble. Most likely, the network of CWPs is loosened during processing of potatoes. PPF showed a WHC of 7.4 expressed as the amount of water held per g of dry matter (mL/g). Reconstituting hot buffer soluble solids with buffer insoluble solids in water gave a WHC comparable to that of PPF. Removal of alkali soluble solids, which mainly comprised xyloglucans, lowered the WHC of the final residue. The results indicated that interactions between CWPs could affect the WHC of PPF. Topics: Alkalies; Biological Transport; Biomechanical Phenomena; Buffers; Cell Wall; Chromatography, High Pressure Liquid; Coumaric Acids; Dietary Fiber; Esterification; Glucans; Hot Temperature; Molecular Structure; Pectins; Polysaccharides; Rhamnose; Solanum tuberosum; Solubility; Species Specificity; Uronic Acids; Water; Xylans | 2013 |
Cross-linking of interfacial layers affects the salt and temperature stability of multilayered emulsions consisting of fish gelatin and sugar beet pectin.
This study assessed the stabilizing effect of enzymatic cross-linking on double-coated emulsions (beet pectin-fish gelatin). The beet pectin layer was cross-linked via ferulic acid groups using laccase (an enzyme that is known to catalyze the oxidation of phenolic groups). Fish gelatin-coated oil droplets (primary emulsion) were mixed at pH 3.5 to promote electrostatic deposition of the beet pectin molecules onto the surfaces of the oil droplets (secondary emulsion). Laccase was then added to promote cross-linking of the adsorbed beet pectin layer. Cross-linked pectin-coated oil droplets had similar or significantly better stability (p < 0.05) than oil droplets of primary or secondary emulsions to NaCl addition (0-500 mM), CaCl(2) addition (0-250 mM), and thermal processing (30-90 °C for 30 min). Freeze-thaw stability and creaming behavior of enzyme-treated, secondary emulsions after two cycles (-8 °C for 22 h; 25 °C for 2 h) were significantly improved (p < 0.05). These results may have important implications for food manufacturers that are in need of emulsions with improved physical stability, for example, emulsions used in frozen foods for sauces or dips. Topics: Beta vulgaris; Coumaric Acids; Cross-Linking Reagents; Drug Stability; Emulsions; Fish Products; Gelatin; Laccase; Pectins; Sodium Chloride; Temperature | 2011 |
Role of protein and ferulic acid in the emulsification properties of sugar beet pectin.
The ability of sugar beet pectin to stabilize 20% w/w limonene oil-in-water emulsions has been investigated. The size of the oil droplets as determined by laser diffraction measurements decreased from about 15 mum to about 6 mum when the pectin concentration increased from 0.05% to 2% w/w but leveled off thereafter, suggesting complete coverage of the oil droplets by the polymer at this optimum concentration. Isotherms for the adsorption of pectin, protein, and ferulic acid were constructed. The adsorption capacities at the oil-water interface of approximately 1.4 and approximately 0.2 mg/m (2) for protein and ferulic acid, respectively, compared to approximately 9.5 mg/m (2) for pectin revealed that the adsorbed fractions of the pectin sample were rich in protein (14.7%) and ferulic acid (2.1%) given that there were only 2.7% protein and 1.06% ferulic acid present in the whole pectin sample. Direct measurements on the adsorbed fraction recovered from the oil droplets via desorption with SDS confirmed that it contained 11.1% protein and 2.16% ferulic acid. The results suggest that one or both of these two functional groups adsorb onto the surface of the oil droplets and stabilize the emulsions. High molecular mass fractions adsorbed preferentially onto oil droplets during emulsification. As compared to those made with gum arabic, the emulsion samples made with sugar beet pectin samples exhibited similar (or even slightly higher) stability. Topics: Adsorption; Beta vulgaris; Coumaric Acids; Drug Stability; Emulsifying Agents; Pectins; Plant Proteins; Polymers; Surface Tension | 2008 |
Sugar beet (Beta vulgaris) pectins are covalently cross-linked through diferulic bridges in the cell wall.
Arabinan and galactan side chains of sugar beet pectins are esterified by ferulic acid residues that can undergo in vivo oxidative reactions to form dehydrodiferulates. After acid and enzymatic degradation of sugar beet cell walls and fractionation of the solubilized products by hydrophobic interaction chromatography, three dehydrodiferulate-rich fractions were isolated. The structural identification of the different compounds present in these fractions was performed by electrospray-ion trap-mass spectrometry (before and after (18)O labeling) and high-performance anion-exchange chromatography. Several compounds contained solely Ara (terminal or alpha-1-->5-linked-dimer) and dehydrodiferulate. The location of the dehydrodiferulate was assigned in some cases to the O-2 and in others to the O-5 of non-reducing Ara residues. One compound contained Gal (beta-1-->4-linked-dimer), Ara (alpha-1-->5-linked-dimer) and dehydrodiferulate. The location of the dehydrodiferulate was unambiguously assigned to the O-2 of the non-reducing Ara residue and O-6 of the non-reducing Gal residue. These results provide direct evidence that pectic arabinans and galactans are covalently cross-linked (intra- or inter-molecularly) through dehydrodiferulates in sugar beet cell walls. Molecular modeling was used to compute and structurally characterize the low energy conformations of the isolated compounds. Interestingly, the conformations of the dehydrodiferulate-bridged arabinan and galactan fragments selected from an energetic criterion, evidenced very nice agreement with the experimental occurrence of the dehydrodiferulated pectins. The present work combines for the first time intensive mass spectrometry data and molecular modeling to give structural relevance of a molecular cohesion between rhamnogalacturonan fragments. Topics: Beta vulgaris; Carbohydrate Conformation; Carbohydrate Sequence; Cell Wall; Coumaric Acids; Galactans; Mass Spectrometry; Models, Molecular; Molecular Sequence Data; Pectins; Polysaccharides | 2005 |
Control of dehydrodiferulate cross-linking in pectins from sugar-beet tissues.
Pectins were extracted from roots, petioles and leaves of sugar beet, and cross-linked using hydrogen peroxide and peroxidase. The effects on dehydrodiferulate formation were monitored by HPLC and TLC. Dehydrodimers were formed in different proportions to those found in vivo. There was a net loss of around 50% of the phenolic groups (monomers plus dimers) during dimerisation. Gel filtration showed that root and petiole pectin, but not leaf pectin, increased in molecular weight during cross-linking. The effects of varying the cross-linking conditions were investigated, and it was found that hydrogen peroxide concentration was the most important factor in controlling both the type and amount of dehydrodiferulate formed. Topics: Beta vulgaris; Chromatography, Gel; Chromatography, Thin Layer; Coumaric Acids; Cross-Linking Reagents; Dimerization; Hydrogen Peroxide; Pectins; Peroxidase; Phenols; Plant Leaves; Plant Roots; Plant Structures; Quaternary Ammonium Compounds; Temperature | 2004 |
Ferulic acid crosslinks in asparagus cell walls in relation to texture.
Post-harvest toughening of asparagus spears is associated with a large increase in monomeric and diferulic acids in the cell walls of stem tissues. The purpose of this study has been to investigate the distribution of these phenolic components among cell wall polymers and the role they play in the formation of associated pectic-xylan-phenolic complexes in relation to post-harvest toughening. The phenolic esters are found in all the extractable polysaccharide fractions, particularly the 0.5 M KOH fraction, as well as the insoluble cellulose-rich residue. The storage-related increase occurs in all fractions but is most prominent in the 0.5 M KOH-soluble components. Degradation of 0.5 M KOH subfractions with pure polysaccharide degrading enzymes has confirmed the occurrence of pectic-xylan-phenolic complexes in which ferulic acid and its dehydrodimers are attached to the xylan component but not to the pectic component. Studies on cell separation show that the maturation- and storage-related increase in thermal stability of cell adhesion (and therefore texture) is probably due to an increase in phenolic cross linking of xylans mainly in the parenchyma tissues. This overcomes the thermal lability of the pectic polysaccharides that are responsible for cell adhesion in immature tissues. The storage-induced appearance of some of the diferulic acid moieties in a number of wall polymer fractions supports the hypothesis that the storage affect is a wound-induced response rather than a continuation of maturation-related activity. Topics: Asparagus Plant; Carbohydrates; Cell Fractionation; Cell Wall; Chemical Precipitation; Coumaric Acids; Cross-Linking Reagents; Ethanol; Food Technology; Hydroxides; Pectins; Phenols; Potassium Compounds; Xylans | 2004 |
Synergy between enzymes from Aspergillus involved in the degradation of plant cell wall polysaccharides.
Synergy in the degradation of two plant cell wall polysaccharides, water insoluble pentosan from wheat flour (an arabinoxylan) and sugar beet pectin, was studied using several main-chain cleaving and accessory enzymes. Synergy was observed between most enzymes tested, although not always to the same extent. Degradation of the xylan backbone by endo-xylanase and beta-xylosidase was influenced most strongly by the action of alpha-L-arabinofuranosidase and arabinoxylan arabinofuranohydrolase resulting in a 2.5-fold and twofold increase in release of xylose, respectively. Ferulic acid release by feruloyl esterase A and 4-O-methyl glucuronic acid release by alpha-glucuronidase depended largely on the degradation of the xylan backbone by endo-xylanase but were also influenced by other enzymes. Degradation of the backbone of the pectin hairy regions resulted in a twofold increase in the release of galactose by beta-galactosidase and endo-galactanase but did not significantly influence the arabinose release by arabinofuranosidase and endo-arabinase. Ferulic acid release from sugar beet pectin by feruloyl esterase A was affected most strongly by the presence of other accessory enzymes. Topics: Arabinose; Aspergillus; Cell Wall; Chenopodiaceae; Coumaric Acids; Drug Synergism; Hydrolases; Pectins; Plants; Polysaccharides; Triticum; Xylans | 2000 |
Characterization of arabinose and ferulic acid rich pectic polysaccharides and hemicelluloses from sugar beet pulp.
Pectic polysaccharides were extracted from sugar beet pulp to yield fractions representing homogalacturonans, rhamnogalacturonans, arabinans and relatively small amounts of glucomannans and xyloglucans. The homogalacturonans had an apparent molecular weight of 21 kDa and contained relatively high amounts of methyl esters and relatively low amounts of acetyl groups as compared with the ramified 'hairy' regions. Three populations which originated from the ramified 'hairy' regions of pectin were distinguished. Two of these were rhamnogalacturonans with high apparent molecular weights of 1300 and 120 kDa, respectively. These populations had a high Ara and ferulic acid content. Despite the high neutral sugar content, these rhamnogalacturonans strongly bound to a DEAE column. The third population which originated from the ramified 'hairy' regions was a neutral population, which did not interact with the DEAE column and had a low apparent molecular weight and a high Ara and ferulic acid content. The arabinan side-chains of the rhamnogalacturonans were heavily branched in all populations. Enzymatic degradation of the xyloglucans showed similarities with apple xyloglucans with respect to the substitution with Fuc and Gal. Topics: Arabinose; Carbohydrate Conformation; Carbohydrate Sequence; Chenopodiaceae; Chromatography, DEAE-Cellulose; Coumaric Acids; Hot Temperature; Mannans; Molecular Sequence Data; Monosaccharides; Pectins; Polysaccharides; Viscosity | 2000 |
Oxidative cross-linking of pectic polysaccharides from sugar beet pulp.
Oxidative cross-linking of three beet pectin extracts with hydrogen peroxide/peroxidase resulted in an increase in viscosity at low concentrations and in the formation of a gel at higher concentrations. Gels were formed using concentrations of 1.5% for an autoclave preparation and one obtained by an acid extraction and of 3% for a second autoclaved extract. It was shown that in the autoclave extracts only rhamnogalacturonans and possibly the arabinans participated in the cross-linking reaction. Cross-linking of the autoclave extracts with ammonium persulfate resulted in a decrease in reduced viscosity and molecular weight, although ferulic acid dehydrodimers were formed. Treatment of the acid extracted pectin with ammonium persulfate gave a slow increase in viscosity and the formation of a high-molecular-weight population was observed. For both oxidative systems, the 8-5 dehydrodimer was predominant after cross-linking. Topics: Ammonium Sulfate; Chenopodiaceae; Chromatography, Gel; Coumaric Acids; Cross-Linking Reagents; Dimerization; Food Additives; Gels; Hot Temperature; Hydrogen Peroxide; Molecular Weight; Oxidation-Reduction; Pectins; Peroxidase; Polysaccharides; Viscosity | 2000 |