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The aim of this study was to characterize the high molecular weight fraction (> 10,000 g/mol) of black spruce sawdust water extracts obtained by controlled auto-hydrolysis and membrane filtration, in order to evaluate its potential as food ingredient (i.e., fiber supplement). The carbohydrate and phenolic content as well as the molecular weight distribution of the filtrated extract (i.e., isolate) were determined by colorimetric, spectrophotometric, and chromatographic methods. Its fermentability was studied during a in vitro batch fermentation experiment, using a chyme-like medium and a standardized eight strains co-culture. Results indicated that the isolate consisted mainly of non-cellulosic polysaccharides (i.e., hemicelluloses) with an average degree of polymerization (DPn) of 63. The galactose:glucose ratio (1:0.29) and the galactose:mannose ratio (1:0.75) indicated a significant amount of galactans among the recovered hemicelluloses. The fermentation profile of the filtrated extract, measured over a period of 30 h, was not significantly different from the fermentation profile of a starch-rich fibre mixture (starch, pectin, mannans, galactans, xylans and fructans at a ratio of 5:2:1:2:2:1). The extract did act as a fiber replacer and was steadily metabolized, inhibiting protein fermentation and the release of free ammonia. Our study suggests that black spruce sawdust may be a valuable source of functional soluble fibers. Further research is however required to assess the full potential of the extract as food ingredient. [ABSTRACT FROM AUTHOR]

Coffee brew is a widespread beverage in human diet with several recognized health benefits. However, the relationship between the chemical portfolio of molecules present in coffee and their bioactive functions are still overlooked. One of the compounds most prevalent in coffee brew are soluble fibers, composed by arabinogalactans and galactomannans polysaccharides and melanoidins, which may influence cholesterol metabolism. Arabinogalactans- and galactomannans polysaccharides- rich fractions as well as coffee extracts were shown to decrease cholesterol bioaccessibility due to their capacity to sequester bile salt. Furthermore, coffee extracts with distinct roasting degrees were shown to affect the bioavailability of cholesterol through Caco-2 cell line model, decreasing sterol permeability, which was attributed to an increased sterol precipitation and its deposition on the apical epithelial surface. Arabinogalactans- and melanoidins-rich fractions were also evaluated regarding the outcome of their fermentability. Both fractions decreased the acetate:propionate ratio, which is indicative of a potential HMG-CoA reductase inhibition. Melanoidin-rich fractions were also shown to decrease the conversion of primary to secondary bile salts, the latter of which are known to be more prone to emulsify cholesterol, impacting cholesterol bioaccessibility and bioavailability. This study demonstrates that coffee exhibits cardioprotective properties, suggesting potential for developing functional food ingredients from coffee extracts to combat cardiovascular diseases, which are among the leading causes of death globally.

Non-invasive routes for insulin delivery are emerging as alternatives to currently painful subcutaneous injections. For pulmonary delivery, formulations may be in powdered particle form, using carriers such as polysaccharides to stabilise the active principle. Roasted coffee beans and spent coffee grounds (SCG) are rich in polysaccharides, namely galactomannans and arabinogalactans. In this work, the polysaccharides were obtained from roasted coffee and SCG for the preparation of insulin-loaded microparticles. The galactomannan and arabinogalactan-rich fractions of coffee beverages were purified by ultrafiltration and separated by graded ethanol precipitations at 50% and 75%, respectively. For SCG, galactomannan-rich and arabinogalactan-rich fractions were recovered by microwave-assisted extraction at 150 °C and at 180 °C, followed by ultrafiltration. Each extract was spray-dried with insulin 10% (w/w). All microparticles had a raisin-like morphology and average diameters of 1–5 µm, which are appropriate for pulmonary delivery. Galactomannan-based microparticles, independently of their source, released insulin in a gradual manner, while arabinogalactan-based ones presented a burst release. The microparticles were seen to be non-cytotoxic for cells representative of the lung, specifically lung epithelial cells (A549) and macrophages (Raw 264.7) up to 1 mg/mL. This work shows how coffee can be a sustainable source of polysaccharide carriers for insulin delivery via the pulmonary route. [ABSTRACT FROM AUTHOR]

MicroRNAs are critical regulators of gene expression in plants and other organisms, and are involved in regulating plethora of developmental processes. Evolutionarily, miRNAs can be ancient and conserved across species or recently evolved and young, which are not conserved across diverse plant groups. MicroRNA775 (miR775) is a non-conserved miRNA identified only in Arabidopsis thaliana (A. thaliana). Here, we investigated the functional significance of miR775 in A. thaliana and observed that miR775 targets a probable β-(1,3)-galactosyltransferase gene at post transcriptional level. Phenotypic analysis of miR775 over-expression lines and the target mutant suggested miR775 regulates rosette size by elongating petiole length and increasing leaf area. Further, the expression of miR775 was found to be up-regulated in response to UV-B and hypoxia. Our results also suggest that miR775 regulated β-(1,3)-galactosyltransferase may involve in regulating the β-(1,3)-galactan content of arabinogalactans. Collectively, our findings establish a role of miR775 in regulating growth and development in A. thaliana. [ABSTRACT FROM AUTHOR]

The instrumental equipment of an espresso coffee machine has a remarkable influence on the extraction of the espresso coffee (EC). This study aims to evaluate the effect of different perforated disc heights and filter baskets, two fundamental parts of the espresso coffee machine, on EC carbohydrates content and composition. Four different heights (4–7 mm) of perforated discs and two different filter baskets were used to prepare Italian style EC and evaluate the feasibility of lowering the amount of ground coffee while keeping the same quality of the standard Italian espresso. Arabica and Robusta coffee beans, with 12 and 14 g of roasted coffee powder, were used to prepare 40 mL of EC, split in two cups. The content of total solids, high molecular weight material and polysaccharides, such as galactomannans (GM) and arabinogalactans (AG), were compared. The results show that the increase of the height of perforated disc affected the extraction of the polysaccharides content in the cup, with a decrease of GM and AG. As a conclusion, the configuration of perforated disc height and the filter used was shown to modulate the chemical profile of EC brew, with impact on espresso coffee cup quality. [ABSTRACT FROM AUTHOR]

The coffee beverage is the second most consumed drink worldwide after water. In coffee beans, cell wall storage polysaccharides (CWSPs) represent around 50 per cent of the seed dry mass, mainly consisting of galactomannans and arabinogalactans. These highly abundant structural components largely influence the organoleptic properties of the coffee beverage, mainly due to the complex changes they undergo during the roasting process. From a nutritional point of view, coffee CWSPs are soluble dietary fibers shown to provide numerous health benefits in reducing the risk of human diseases. Due to their influence on coffee quality and their health-promoting benefits, CWSPs have been attracting significant research attention. The importance of cell walls to the coffee industry is not restricted to beans used for beverage production, as several coffee by-products also present high concentrations of cell wall components. These by-products include cherry husks, cherry pulps, parchment skin, silver skin, and spent coffee grounds, which are currently used or have the potential to be utilized either as food ingredients or additives, or for the generation of downstream products such as enzymes, pharmaceuticals, and bioethanol. In addition to their functions during plant development, cell walls also play a role in the plant's resistance to stresses. Here, we review several aspects of coffee cell walls, including chemical composition, biosynthesis, their function in coffee's responses to stresses, and their influence on coffee quality. We also propose some potential cell wall–related biotechnological strategies envisaged for coffee improvements. [ABSTRACT FROM AUTHOR]

Marsypianthes chamaedrys (Lamiaceae) is a medicinal plant popularly used against envenomation by snakebite. Pharmacological studies have shown that extracts of M. chamaedrys have antiophidic, anti-inflammatory and anticoagulant properties, supporting the ethnopharmacological use. In this study, an aqueous extract of aerial parts of M. chamaedrys showed anticoagulant activity in the activated partial thromboplastin time assay (0.54 IU/mg). The bioassay-guided fractionation using ethanol precipitation and gel filtration chromatography on Sephadex G-50 and Sephadex G-25 resulted in a water-soluble fraction with increased anticoagulant activity (Fraction F2−A; 2.94 IU/mg). A positive correlation was found between the amount of uronic acids and the anticoagulant potential of the active samples. Chemical and spectroscopic analyses indicated that F2−A contained homogalacturonan, type I rhamnogalacturonan, type II arabinogalactan and α-glucan. UV and FT–IR spectra indicated the possible presence of ferulic acid. Pectic polysaccharides and type II arabinogalactans may be contributing to the anticoagulant activity of the aqueous extract of M. chamaedrys in the APTT assay. • The decoction of aerial parts of Marsypianthes chamaedrys prolonged APTT (0.54 IU/mg). • Bioassay-guided fractionation employed ethanol precipitation and Sephadex gels. • A fraction with marked anticoagulant activity was obtained (2.94 IU/mg). • This polysaccharide-enriched fraction was characterized by NMR, UV, FT-IR and HPSEC. • Pectins (HG, RG-I), AG-II and α-glucan were identified in the anticoagulant fraction. [ABSTRACT FROM AUTHOR]

Cereals have captured global importance owing to the presence of bioactive moieties in cell wall. Numerous components have been considered but non-starch polysaccharides (NSP) of cereals cell wall are of prime concern. In this comprehensive review, the basic aim is to elaborate the functional and nutritional importance of cereals cell wall with special reference to NSP. Among bioactive components of cell wall, NSP, such as arabinoxylans, ß-glucans, and arabinogalactans of wheat and barley, have gained much importance. Moreover, literature revealed that NSP have greater role as prebiotic, immunomodulator, antioxidant, anti-diabetic, and cardio-protector as well as major food applications.

Highlights • Microwave assisted extractions of spent coffee grounds (SCG) polysaccharides were performed. • Temperature (T) and time (t) are the key factors in the microwave extraction. • Arabinogalactans (AG) extraction is favoured at 170 °C whereas galactomannans (GM) are favoured at lower T. • At 200 °C mainly GM oligosaccharides are recovered. • Alkali conditions protect against polysaccharides degradation at high T and low t. Abstract This work studies the microwave-assisted extraction conditions for recovery of polysaccharides from spent coffee grounds, including their effect on arabinogalactans and galactomannans polymerization and branching structural features. Temperature (140, 170, and 200 °C) has the most significant impact on total extracted mass (η total soluble solids) and sugars yield (η sugars), arabinogalactans (η AG) and galactomannans (η GM), and polysaccharide mass ratio (η AG / η GM). Time (2, 5, and 10 min) and alkali (diluted 0.1 M NaOH) treatments have less influence. Alkali treatment and shorter time (2 min) provided a protective effect against polysaccharides degradation. At 170 °C, the yield of arabinogalactans was found to be significantly higher than that of galactomannans (η AG / η GM >1). Increasing temperature to 200 °C leads to decrease the polymerization of polysaccharides, promoting the formation of debranched polysaccharides and oligosaccharides. This study shows that the optimum conditions for polysaccharides extraction cannot be selected only by mass yield but need to be defined according to the desired structural features for the specific applications. [ABSTRACT FROM AUTHOR]

Background and aims In the Brassicaceae family, apomictic development is characteristic of the genus Boechera. Hybridization, polyploidy and environmental adaptation that arose during the evolution of Boechera may serve as (epi)genetic regulators of apomictic initiation in this genus. Here we focus on Boechera stricta, a predominantly diploid species that reproduces sexually. However, apomictic development in this species has been reported in several studies, indicating non-obligate sexuality. Methods A progressive investigation of flower development was conducted using three accessions to assess the reproductive system of B. stricta. We employed molecular and cyto-embryological identification using histochemistry, transmission electron microscopy and Nomarski and epifluorescence microscopy. Key Results Data from internal transcribed spacer (ITS) and chloroplast haplotype sequencing, in addition to microsatellite variation, confirmed the B. stricta genotype for all lines. Embryological data indicated irregularities in sexual reproduction manifested by heterochronic ovule development, longevity of meiocyte and dyad stages, diverse callose accumulation during meiocyte-to-gametophyte development, and the formation of triads and tetrads in several patterns. The arabinogalactan-related sugar epitope recognized by JIM13 immunolocalized to one or more megaspores. Furthermore, pollen sterility and a high frequency of seed abortion appeared to accompany reproduction of the accession ES512, along with the initiation of parthenogenesis. Data from flow cytometric screening revealed both sexual and apomictic seed formation. Conclusion These results imply that B. stricta is a species with an underlying ability to initiate apomixis, at least with respect to the lines examined here. The existence of apomixis in an otherwise diploid sexual B. stricta may provide the genomic building blocks for establishing highly penetrant apomictic diploids and hybrid relatives. Our findings demonstrate that apomixis per se is a variable trait upon which natural selection could act. [ABSTRACT FROM AUTHOR]

An instant coffee fraction, rich in arabinogalactans, obtained by ultrafiltration, using 1 and 5 kDa membranes, has previously shown in vitro stimulatory activity on BALB/c mice spleen B lymphocytes. The compounds inducing lymphocytic activation were shown to elute, mainly near the void volume by size-exclusion chromatography, using Bio-Gel P6 (1–6 kDa). Treatment of the compounds with chymotrypsin, a digestive protease, did not affect the induced B lymphocyte activation. On the contrary, hydrolysis with an α- l -arabinofuranosidase, removing single terminally-linked arabinose residues, decreased the extent of B cell activation. The immunostimulatory activity of these compounds was also observed by in vitro experiments, using bone marrow-derived macrophages and dendritic cells as responders. Altogether, these results show the relevance of single arabinose residues, present at the non-reducing end of polymeric compounds, to the coffee stimulatory activity in cells mediating innate and acquired immunity. [ABSTRACT FROM AUTHOR]

Cereals have captured global importance owing to the presence of bioactive moieties in cell wall. Numerous components have been considered but non-starch polysaccharides (NSP) of cereals cell wall are of prime concern. In this comprehensive review, the basic aim is to elaborate the functional and nutritional importance of cereals cell wall with special reference to NSP. Among bioactive components of cell wall, NSP, such as arabinoxylans, ß-glucans, and arabinogalactans of wheat and barley, have gained much importance. Moreover, literature revealed that NSP have greater role as prebiotic, immunomodulator, antioxidant, anti-diabetic, and cardio-protector as well as major food applications. [ABSTRACT FROM AUTHOR]

Galactans are linear structures mainly found in arabinogalactan and RG-I side chains. As a follow-up to our work on both β- (1→3)-linked and β-(1→4)-linked galactans, we herein report a convergent synthesis of β-(1→6)-galactan using our previously synthesized 4,6-benzylidene protected disaccharide as a key building block. However, the regioselective reductive opening of the 4,6-benzylidene protected disaccharide turned out to become more challenging as the length of the oligosaccharide increased and a second differential protected disaccharide building block carrying a chloroacetyl group on the 6-position was used to elongate the chain in a more efficient way. [ABSTRACT FROM AUTHOR]

To study structure-function relationships of pectic polysaccharides with their immunostimulatory activity, broccoli by-products were used. Pectic polysaccharides composed by 64 mol% uronic acids, 18 mol% Ara, and 10 mol% Gal, obtained by hot water extraction, activated B lymphocytes in vitro (25–250 μg/mL). To disclose active structural features, combinations of ethanol and chromatographic fractionation and modification of the polysaccharides were performed. Polysaccharides insoluble in 80 % ethanol (Et80) showed higher immunostimulatory activity than the pristine mixture, which was independent of molecular weight range (12–400 kDa) and removal of terminal or short Ara side chains. Chemical sulfation did not promote B lymphocyte activation. However, the action of pectin methylesterase and endo -polygalacturonase on hot water extracted polysaccharides produced an acidic fraction with a high immunostimulatory activity. The de-esterified homogalacturonan region seem to be an important core to confer pectic polysaccharides immunostimulatory activity. Therefore, agri-food by-products are a source of pectic polysaccharide functional food ingredients. [Display omitted] • Pectic polysaccharides from broccoli by-products activate B lymphocytes. • Immunostimulation do not rely on terminal arabinose and molecular weight. • Chemical sulfation does not impact immunostimulatory activity. • De-esterified homogalacturonan regions are an important core for activity. [ABSTRACT FROM AUTHOR]

A short, robust, and expedient synthesis of various aryl α- l-arabinofuranosides using a trichloroacetimidate precursor is described. The procedure is compatible with a range of phenols with varying p Ka values and may be amenable for preparing a wide range of other glycosides. [ABSTRACT FROM AUTHOR]

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 . Pent 1–2 CQA 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. [ABSTRACT FROM AUTHOR]

In this review, we summarized the research data on the contents and chemical structures of pectic polysaccharides, arabinogalactans, and arabinogalactan proteins from coniferous species. The presently known structures of these polymers are given. Special attention is given to the description of chemical structural features of pectic polysaccharides from the Abies sibirica and Picea abies tree verdures (branches and needles). Three models presently suggested for the description of pectin macromolecular structures are discussed. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Arabinogalactans (AGs) are branched galactans to which arabinose residues are bound as side chains and are widely distributed in plant cell walls. They can be grouped into two types based on the structures of their backbones. Type I AGs have β-1,4-galactan backbones and are often covalently linked to the rhamnogalacturonan-I region of pectins. Type II AGs have β-1,3-galactan backbones and are often covalently linked to proteins. The main enzymes involved in the degradation of AGs are endo-β-galactanases, exo-β-galactanases, and β-galactosidases, although other enzymes such as α- l-arabinofuranosidases, β- l-arabinopyranosidases, and β- d-glucuronidases are required to remove the side chains for efficient degradation of the polysaccharides. Galactanolytic enzymes have a wide variety of potential uses, including the bioconversion of AGs to fermentable sugars for production of commodity chemicals like ethanol, biobleaching of cellulose pulp, modulation of pectin properties, improving animal feed, and determining the chemical structure of AGs. This review summarizes our current knowledge about the biochemical properties and potential applications of AG-degrading enzymes. [ABSTRACT FROM AUTHOR]

Abstract: The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source of polysaccharides. In the present work, the feasibility of microwave superheated water extraction of polysaccharides from SCG was studied. Different ratios of mass of SCG to water, from 1:30 to 1:5 (g:mL) were used for a total volume of 80mL. Although the amount of material extracted/batch (MAE1) increased with the increase of the concentration of the sample, the amount of polysaccharides achieved a maximum of 0.57g/batch for 1:10. Glycosidic-linkage composition showed that all extraction conditions allowed to obtain mainly arabinogalactans. When the unextracted insoluble material was re-extracted under the same conditions (MAE2), a further extraction of polysaccharides was observed (0.34g/batch for 1:10), mainly galactomannans. Also, a high amount of oligosaccharides, mainly derived from galactomannans, can be obtained in MAE2 (0.96g/batch for 1:10). This technology allows to obtain galactomannans and arabinogalactans in proportions that are dependent on the operating conditions. [Copyright &y& Elsevier]

Abstract: In this work a physico-chemical characterization of the polysaccharide fraction of the exudates of Launaea acanthodes, a common medicinal species in central regions of Iran, was performed. The extraction of the polysaccharide fraction of the exudates was described. The structure characterization of the polysaccharide was performed with mono and bi-dimensional NMR spectroscopy techniques, which allowed the chemical composition and the relative monomers abundance of the extracted fraction to be estimated. The constituent monosaccharides were predominantly galactose, rhamnose, arabinose and galacturonic acid residues. Interchain association phenomena in the main arabinogalactans component (Mw=33.550Da) were evidenced both from high-performance size-exclusion chromatography (HP-SEC–TDA), and by intrinsic viscosity ([η]0 =0.323dlg−1 in water and [η]0 =0.115dlg−1 in NaNO3 0.1M at 20°C) measurement and the Huggings coefficient λ. Due to the formation of hyperentanglements, a unique function of C[η]0 cannot be defined. The technological consequence was that once structured, the polysaccharide network did not express a sufficient degree in polymer orientation and therefore cast films showed weak mechanical properties. [Copyright &y& Elsevier]

Abstract: An immunomodulating pectic polymer, GOA1, obtained from the aerial parts of the Malian medicinal plant Glinus oppositifolius (L.) Aug. DC. (Aizoaceae) has previously been reported to consist of arabinogalactans type I and II, probably linked to a rhamnogalacturonan backbone. To further elucidate the structure of the polymer GOA1, enzymatic degradation studies and weak acid hydrolysis were performed. Five different glycosidases were used, endo-α-d-(1→4)-polygalacturonase, exo-α-l-arabinofuranosidase, endo-α-l-(1→5)-arabinanase, endo-β-d-(1→4)-galactanase and exo-β-d-galactosidase. It appears that GOA1 may contain a structural moiety consisting of a 1,3-linked galactopyranosyl (Galp) main chain with 1,6-linked Galp side chains attached to position 6 of the main chain. The 1,6-linked Galp side chain may be branched in position 3 with arabinofuranosyl (Araf) side chains. A 1,4-linked Galp backbone which might carry side chains or glycosyl units attached to position 3 is also a structural element in the polymer. We further show that GOA1 induce proliferation of B cells and the secretion of IL-1β by macrophages, in addition to a marked increase of mRNA for IFN-γ in NK-cells. To elucidate structure–activity relations the native polymer and the digested fractions were tested for complement fixing activity and intestinal immune stimulating activity. The partial removal of Araf residues after enzymatic degradations did not affect the bioactivities, while the acid hydrolysed fraction showed reduced complement fixing activity. A decrease in Araf units, 1,3,6-linked Galp units and a partial hydrolysed rhamnogalacturonan backbone, in addition to a reduction in molecular weight are factors that might have contributed to reduced bioactivity. [Copyright &y& Elsevier]

Arabinogalactan and pectin (named silenan) were isolated from Silene vulgaris (M.) G. callus. Fractionation by ion-exchange chromatography on DEAE-cellulose and digestion with pectinase demonstrated that silenan from S. vulgaris callus (80% of D-galacturonic acid) and silenan from the aerial part of the campion S. vulgaris are similar: both pectins contain a high quantity of homogalacturonan segments. The NMR spectral data and mass spectrometry of the purified polysaccharide and its fragment obtained by Smith degradation confirmed that the core of the arabinogalactan consisted of the different segments of β-1,3-D-galactopyranan. Some of the β-galactopyranose residues of the backbone are branched at O-6. The side chains of the arabinogalactan were shown to contain residues of terminal and 3-O-substituted β-galactopyranose, terminal α-arabinofuranose and α-rhamnopyranose, and 2-O-substituted α-rhamnopyranose. The α-rhamnopyranose residues in the sugar chain appeared to be 2-O-glycosylated by the β-1,4-D-galactopyranosyl uronic acid residues. [ABSTRACT FROM AUTHOR]

Abstract: Extraction of peeled fruits of Opuntia ficus indica afforded with 3.8% yield a mucilage, which contained 23.4% of galacturonic acid. Total hydrolysis of a mucilage and gas–liquid chromatographic analysis of the derived alditol acetates indicated the presence of arabinose, rhamnose, xylose and galactose in the molar ratio 1.0:1.7:2.5:4.1. Gel permeation chromatography on Sepharose CL-4B showed the polysaccharide to be composed of at least five fractions. Treatment with cetrimide allowed the separation of an insoluble fraction (44.3% yield), which contained 28.0% of uronic acid. This fraction contained xylose, rhamnose and galactose in the molar ratio 1.0:2.5:2.8. The fraction soluble in cetrimide (15.6% yield) contained 16.0% uronic acid, and arabinose and galactose in the molar ratio of 1:2.2. It is composed of two main subfractions as shown by gel permeation chromatography. These results indicate that the mucilage from fruits O. ficus indica is a complex mixture of polysaccharides, less than 50% corresponding to a pectin-like polysaccharide. [Copyright &y& Elsevier]

Abstract: An arabinogalactan was isolated from a hot water extract of freeze-dried cells of the green microalga, Chlorella pyrenoidosa. This hot water extract is a proprietary immunomodulator, with the trademark Respondin™ (ONC-107). The arabinogalactan was recovered from the ethanol-soluble fraction of the supernatant resulting from a process that involved controlled ethanol precipitation followed by size exclusion chromatography on Sephadex G-100, then Cetavlon precipitation. Sugar analyses, GC–MS data for (S)-2-octyl glycosides, and 1D and 2D NMR experiments established unambiguously that the repeating unit was →2)-α-l-Araf-(1→3)-[α-l-Araf-(1→4)]-β-d-Galp-(1→. This structure does not fit into any of the known classes of arabinogalactans. SEC/MALS experiments gave a molecular mass for the arabinogalactan isolated as 47±4kDa but the original structure was probably larger. [Copyright &y& Elsevier]

A water-soluble polysaccharide complex (A) composed of galactose (17.9%), 3-O-methyl-galactose (3.0%), glucose (15.5%), mannose (8.3%), arabinose (30.4%), xylose (7.6%), fucose (2.6%), rhamnose (6.7%), and uronic acids (8.0%) has been isolated from the aerial parts of sage (Salvia officinalis L.) by cold water extraction. It showed a broad molecular-mass distribution pattern (Mw∼2000–93 000) with a predominance of polymers with Mw<10 000. Ion-exchange chromatography of A afforded six polymeric fractions (A1–A6) in which arabinogalactans associated with galacturonan and/or rhamnogalacturonan backbones prevail. Sage polysaccharides were examined for their immunomodulatory activity in the comitogenic thymocyte test which is interpreted as being an in vitro correlate of adjuvant activity. The acidic polysaccharide fractions A2, A3 and A4 exhibited the highest mitogenic and comitogenic activities of all fractions tested, and relatively high SIcomit/SImit ratios ∼3 indicate potential adjuvant properties of these polysaccharides. [Copyright &y& Elsevier]

Coffee beans (arabica) with different degrees of roast were sequentially extracted with water (90 °C, 1 h), water (170 °C, 30 min), and 0.05 M NaOH (0 °C, 1 h). The amount and composition of polysaccharides, oligosaccharides and monosaccharides in the extracts and residues were analyzed. The results were compared with the composition of the same batch of green arabica coffee beans. Although part of our results were already reported in rather fragmented studies, this study gives a more complete overview of the amount and composition of unextractable polymers, extractable polymers, oligomers, monomers, and their conversion into (non-sugar) degradation products as a function of their degree of roast.It was found that most carbohydrates in the roasted coffee bean were present as polysaccharides (extractable or unextractable). The fact that only a small part of the carbohydrates in the extracts were recovered as oligomer and even less as monomers, showed that oligomers and especially monomers were converted very rapidly into Maillard and pyrolysis products. Cellulose remains unextractable and its solubility was not affected by the degree of roast. Galactomannans were also mainly present as unextractable polymers in green beans, but were solubilized to a large extent with increasing degrees of roast. The arabinogalactans in the roasted bean were highly soluble at the extraction conditions used. The arabinose as present as side-chains in the arabinogalactans were found to be more susceptible to degradation at more severe roasting conditions than the galactans. Also evidence was found that populations of arabinogalactans with very different ara:gal ratios exist in the roasted beans as well as in the green beans. [Copyright &y& Elsevier]

Polysaccharides were sequentially extracted from green and roasted Coffea arabica beans with water (90 °C), EDTA, 0.05, 1, and 4 M NaOH and characterized chemically. Additionally, the beans were subjected to a single extraction with water at 170 °C. Green arabica coffee beans contained large proportions of 1→4-linked mannans, of which on average 1 in every 23 mannopyranose residues was branched with single unit galactose side-chains at O-6. A part of these galactomannans could be extracted relatively easy with water and EDTA. These galactomannans were found to have a relatively high degree of branching (gal:man∼1:8) and a relatively low molecular weight in comparison to the remaining galactomannans (gal:man∼1:15–24). Additionally, 1→3-linked galactans, heavily branched at O-6 with side-chains containing arabinose and galactose residues, were present in the green coffee beans, as well as smaller amounts of pectins, cellulose, and xyloglucans.Roasting resulted in a loss of 8% of the dry weight. This could be partly explained by the relatively high percentage of sugars which was lost during the roasting process, most probably as a result of conversion into, e.g. Maillard and pyrolysis products. After roasting the extractability of polysaccharides was increased significantly. A decrease in the degree of branching as well as a decrease in molecular weight of arabinogalactans, galactomannans, and xyloglucans was observed after roasting. [Copyright &y& Elsevier]

Various carbohydrate polymers have during the last decades been shown to be responsible for biological effects, either by exhibiting the effect themselves or by inducing effects via complex reaction cascades. These are e.g. anti-inflammatory, immunostimulating, complement activation, antithrombotic, antidiabetic and infection protectant. Modern pharmaceutical industry has extensive research programs where the aim is to obtain information on traditional use of medicinal plants still being in use, and perform screening of these for the claimed biological activity and follow the isolation of chemical compounds with the relevant activity tests, but few of the programs focus on polysaccharides. Various plants have been used for treating wounds of different types, both internally and externally and bioassay guided isolation of active compounds in these plants showed that in many cases, polysaccharides were responsible for the biological activity. Many of these polysaccharide fractions have been shown to activate complement. The active compounds studied are often of the pectic type, but acetylated glucomannans and glucans are also among those having the same kind of effect and certain structure/activity relationships of these polysaccharides is discussed. [ABSTRACT FROM AUTHOR]

Plant cell walls are dynamic structures that undergo specific remodeling events during plant defence responses. Changes in the coordinated partitioning of carbohydrates between the cytosol and the extracellular milieu may direct sheath cell wall remodeling that occurs in a wheat–endophytic interaction with a Fusarium proliferatum (F.p.) species. Increased levels of apoplastic myoinositol and glucose were apparent in the endophyte-positiveF.p. -infected sheaths from asymptomatic greenhouse-grown wheat. The F.p. -infected plants exhibited a resistant-like response under conditions of host stress. Cellular concentrations of galactinol, glucose, fructose, sucrose and melibiose increased in wheat sheaths infected with the F.p. species compared to the non-infected control sheaths. In addition, the symptomatic F.p. -infected plants showed increased accumulation of arabinogalactans, syringyl lignin and ferulate dimers in the sheath epidermal walls in contact with the endophyte. These were distinct from the carbohydrate, lignin and ferulate deposition patterns in the non-infected control sheaths. Further examination of sheath walls in F.p. -infected and control wheat using laser scanning confocal microscopy revealed a distinct spectral emission profile localized to the epidermal walls in F.p. -infected plants that was concomitant with the enhanced deposition of wall-bound ferulates. Increased levels of total ferulate dimers, particularly the 8- O -4 and 5–5 linkages were found in the F.p. -infected compared to control sheaths. [Copyright &y& Elsevier]

The degree and nature of polysaccharide degradation at different roasting levels was determined for three Arabica (Coffea arabica) bean varieties. Between 12 and 40% of the bean polysaccharides were degraded depending on the roasting conditions. The thermal stability of the arabinogalactans, (galacto)mannans and cellulose was markedly different. The arabinogalactans and mannans were degraded up to 60 and 36%, respectively, after a dark roast, while cellulose showed negligible evidence of degradation. Roasting led to increased solubility of both the arabinogalactans and (galacto)mannans from the bean but the structural modifications, which accompanied this change in solubility, were different for each polysaccharide. Despite the moderate degradation of the (galacto)mannans, those remaining in the bean after roasting showed no evidence of change to their molecular weight even after a dark roast. In contrast, arabinogalactans were depolymerised after a light roast both by fission of the galactan backbone and loss of arabinose from the sidechains. The recently discovered covalent link between the coffee bean arabinogalactans and protein survived roasting. The glucuronic acid component of the AG was degraded markedly after a dark roast, but approximately 30% of the original content remained as part of the AG polymer. The results show that polysaccharide degradation during roasting is more marked than previously documented, and points to roasting induced changes to the polysaccharides as major factors in the changing physicochemical profile of the coffee bean during processing. [Copyright &y& Elsevier]

The arabinogalactan content of green coffee beans (Coffea arabica var. Yellow Caturra) was released by a combination of chemical extraction and enzymatic hydrolysis of the mannan–cellulose component of the wall. Several arabinogalactan fractions were isolated, purified by gel-permeation and ion-exchange chromatography and characterised by compositional and linkage analysis. The AG fractions contained between 6 and 8% glucuronic acid, and gave a positive test for the β-glucosyl-Yariv reagent, a stain specific for arabinogalactan-proteins. The protein component accounted for between 0.5 and 2.0% of the AGPs and contained between 7 and 12% hydroxyproline. The AG moieties displayed considerable heterogeneity with regard to their degree of arabinosylation and the extent and composition of their side-chains. They possessed a MW average of 650 kDa which ranged between 150 and 2000 kDa. An investigation of the structural features of the major AG fraction, released following enzymatic hydrolysis of the mannan–cellulose polymers, allowed a partial structure of coffee arabinogalactan to be proposed. [Copyright &y& Elsevier]

Using extraction with 0.75% aqueous ammonium oxalate, the following polysaccharide fractions were isolated: tanacetans TVF, TVS, and TVR from floscules, sprouts, and roots, respectively, of Tanacetum vulgare L., spread throughout the European North of Russia. The sugar chain of tanacetan TVF consists of D-galacturonic acid (61.4%), arabinose (14.7%), galactose (10.2%), and rhamnose (3.7%) as the main constituents as well as xylose, glucose, mannose, apiose, and 2- O-methylxylose in trace amounts. Tanacetans TVS and TVR were shown to differ in the sugar quantitative composition. They contain 67 and 28% galacturonic acid, respectively. A partial acid hydrolysis of the tanacetan TVF gave a polysaccharide fragment TVF1, α-1,4- D-galacturonan (GalA 98.2%). Digestion with pectinase (α-1,4- D-polygalacturonase) resulted in fragment TVF3, containing residues of arabinose (27.1%) and galactose (17.3%). NMR spectroscopy allowed detection of the terminal residues of α-Ara f and β-Gal p as well as of the residues of α-Ara p substituted in 3,5- and 5-positions. Thus, tanacetan TVF was proved to be a pectic polysaccharide. [ABSTRACT FROM AUTHOR]

Water-soluble polysaccharide fractions VO1–VO4 were isolated from the squeezed berries of the snowball tree ( Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of α-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of β-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of α-arabinofuranose at a Gal : Ara ratio of 3 : 1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus. [ABSTRACT FROM AUTHOR]

Dietary fibers have beneficial effects on human health through the interaction with gut microbiota. Larch wood arabinogalactan (LA-AG) is one kind of complex soluble dietary fibers that may be utilized by human gut microbiota. In this study, the LA-AG degradation by gut microbiota were characterized by investigating the change of LA-AG, microbiota composition, and the production of short-chain fatty acids (SCFAs), lactic acid, succinic acid, as well as volatile organic metabolites. During the fermentation, pH decreased continuously, along with the organic acids (especially acetic acid and lactic acid) accumulating. LA-AG was degraded by gut microbiota then some beneficial metabolites were produced. In addition, LA-AG inhibited the proliferation of some gut microbiota (Unclassified_Enterobacteriaceae and Citrobacter) and the accumulation of some metabolites (Sulfide and indole) released by gut microbiota. LA-AG was partly fermentable fibers with prebiotic potential for human gut health. • LA-AG could be partly degraded by gut microbiota and play a probiotic role. • LA-AG promoted the abundance of Bifidobacterium and Blautia. • LA-AG inhibited the abundance of Unclassified_Enterobacteriaceae and Citrobacter. • LA-AG improved accumulation of organic acids and decreased the level of indoles. [ABSTRACT FROM AUTHOR]

Rapid effects of indole‐3‐acetic acid (IAA) on the mechanical properties of cell wall, and sugar compositions, intrinsic viscosity and molecular weight distribution of cell wall polysaccharides were investigated with excised epicotyl segments of Vigna angularis Ohwi et Ohashi cv. Takara. 1 IAA caused cell wall loosening as studied by stress‐relaxation analysis within 15 min after the IAA application. 2 IAA stimulated the decrease in the content of arabinose and galactose in the hemicellulose 1 h after its application. The amounts of other component sugars in the cell wall polysaccharides remained constant during the IAA‐induced segment growth. 3 The intrinsic viscocity of the pectin increased as early as 30 min after the IAA application. This effect was not prevented when elongation growth of the segment was osmotically suppressed by 0.15 M mannitol. 4 Gel permeation chromatography of the pectin on a Sepharose 4 B column demonstrated that IAA caused increase in the mass‐average molecular weight of the pectin. Analysis of the sugar compositions of the pectin eluted from the Sepharose 4 B column indicated that IAA increased the molecular weight of the polysaccharides composed of uronic acid, galactose, rhamnose and arabinose. This effect became apparent within 30 min after the IAA application. Furthermore, IAA increased the molecular weight of the pectin when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol. 5 Hemicellulose of the cell wall chromatographed on a Sepharose CL‐4 B column. Analysis of the neutral sugar compositions and the iodine staining property (specific for xyloglucans) of the polysaccharide solution eluted from the column indicated that the hemicellulose consisted of xyloglucans, arabinogalactans and polysaccharides composed of xylose and/or mannose. IAA caused a decrease in the arabinogalactan content and depolymerization of xyloglucans. These IAA effects became apparent within 30 min after the IAA application. These changes occurred even when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol. Polymerization of the pectin, degradation of arabinogalactans and depolymerization of xyloglucans appear to be involved in the mechanism by which IAA induces cell wall loosening and therefore extension growth of cells. [ABSTRACT FROM AUTHOR]

• Arabinofuranosidases have largely remain neglected. • Arabinofuranosidases have potential in waste valorization. • Synergism with other enzymes increases their applicability. • Applications in food, beverages, pharma, bioethanol, paper-pulp, feed industries. Alpha-L-arabinofuranoside arabinofuranohydrolase (ARA), more commonly known as alpha-L-arabinofuranosidase (E.C. number 3.2.1.55), is a hydrolytic enzyme, catalyzing the cleavage of alpha-L-arabinose by acting on the non-reducing ends of alpha-L-arabinofuranosides, alpha-L-arabinans containing (1,3)- and/or (1,5)-linked arabinoxylans and arabinogalactans. ARA functions as debranching enzyme removing arabinose substituents from arabinoxylan and arabinoxylooligomers, thereby, boosting the hydrolysis of arabinoxylan fraction of hemicellulose and improving bioconversion of lignocellulosic biomass. Previously, comprehensive information on this enzyme has not been reviewed thoroughly. Therefore, the main aim of this review is to highlight the important properties of this interesting enzyme, microorganisms used for its production, and enhanced production using genetic engineering approach. An account on synergism with other biomass hydrolyzing enzymes and various industrial applications of this enzyme has also been provided along with an outlook on further research and development. [ABSTRACT FROM AUTHOR]

• Microwave-assisted extraction allows to quickly obtain up to half of coffee content. • Temperature was the most preponderant factor for coffee extracts differentiation. • The increase in the extraction yield was linked to higher arabinogalactans extraction. • The brown colour of the extracts can be modulated by MAE conditions. • Extracts with commercial coffee brew chemical properties can be achieved using MAE. Microwave-assisted extraction (MAE) allows to quickly achieve soluble compounds from solid matrices due to the promotion of temperatures higher than the solvent (atmospheric) boiling point, once a closed-vessel system is used for operating at high pressure. In this study, the feasibility of MAE for producing high yield coffee extracts with properties that allow their commercial application was tested through a quality by design approach. It was studied the influence of time of extraction (1, 5.5, 10 min), temperature (120, 150, 180 °C) and the mass-to-volume (m/V) ratio (2, 4, 6 g/60 mL) in the overall extraction yield (24–47%, w/w), carbohydrates content (18–43%, w/w), sugars composition, caffeine (4–7%, w/w), 5-caffeoylquinic acid (1–2%, w/w), colour and antioxidant activity of the extracts. FTIR analysis was used to study the resemblance of coffee extracts and commercial instant coffee. MAE allowed overall extraction yields considerably higher than the home brewing methods, mainly when performed at 180 °C, with a substantial increase in arabinogalactans (AG) extraction associated to higher temperatures. Temperature exerted a crucial role in coffee extracts differentiation, although time and m/V ratio also lead to different values in the responses. Under a circular economy concept, MAE was able to produce extracts that can be used as defined food/brew ingredients and provides a galactomannan and cellulose rich residue that can also be valued as a source of dietary fibre. [ABSTRACT FROM AUTHOR]