Structural Profiling of Xyloglucans from Food Plants by High-Performance Anion-Exchange Chromatography with Parallel Pulsed Amperometric and Mass Spectrometric Detection

Structure-function relationship of the brown seaweed Undaria pinnatifida laminaran: Protein kinase C-mediated mucus secretion and gut barrier restoration

Ulcerative colitis is a chronic inflammatory condition of the intestine characterized by mucosal damage and a compromised epithelial barrier. This study explored the protective and therapeutic potential of laminaran derived from the brown seaweed Undaria pinnatifida in promoting mucin secretion and restoring mucosal barrier integrity. Physicochemical analysis revealed laminaran as having a β-(1 → 3)-linked glucose backbone with β-(1 → 6)-linked branches and a molecular weight of 14.41 kDa. In vitro experiments revealed that laminaran enhanced the expression of mucin-related proteins in a lipopolysaccharide-induced LS174T model. Laminaran also upregulated the expression of sulfotransferases, which are essential for mucin sulfation, and promoted vesicular transport by increasing the expression of vesicle-associated membrane protein 8 and synaptosome-associated protein-23, facilitating mucin secretion. These effects are mediated through the protein kinase C (PKC) pathway, which involves PKCα and PKCβII. In an in vivo model, laminaran alleviated dextran sulfate sodium-induced colitis, increasing mucus thickness and overall intestinal barrier function. These results suggest that laminaran is a promising therapeutic agent for treating ulcerative colitis, suggesting a novel approach to restoring the mucosal barrier and reducing intestinal inflammation. This study lays the groundwork for developing laminaran-based treatments for ulcerative colitis and other intestinal diseases associated with epithelial barrier dysfunction.

Comprehensive Characterization of the Polysaccharide Composition and Xyloglucan Architecture of Four Berry Fruits and Their Macroscopic Fruit Components

For the structural characterization of the fiber polysaccharides of berry fruits in general and their xyloglucan architecture in particular, chokeberries, cranberries, raspberries, and red currants were subjected to monomer analysis after acid hydrolysis (HPAEC-PAD), methylation analysis (GC-FID/MS), and a specific xyloglucanoligosaccharide profiling approach (HPAEC-PAD/MS). The characterization was carried out on the whole fruit and on macroscopic fruit components: the fruit pulp and press residues, the latter being separated into seeds and seedless residues (mainly epidermal and vascular tissues). The complementary data provide a comprehensive insight into the cell wall polysaccharide architecture of these frequently consumed and fiber-rich plant foods. In addition to their substantial structural variability, their cell walls were found to be less rich in xyloglucans and galacturonic acid containing polysaccharides than expected for fruits of dicotyledonous plants. Furthermore, the botanically diverse fruit types were classified with respect to their xyloglucan architecture in accordance with taxonomy: chokeberries, raspberries, and red currants exhibited XXXG-type fucogalactoxyloglucans. Differently, cranberries demonstrated a unique diversity of both arabino- and fucogalactoxyloglucans.

Saccharide mapping as an extraordinary method on characterization and identification of plant and fungi polysaccharides: A review

Saccharide mapping was a promising scheme to unveil the mystery of polysaccharide structure by analysis of the fragments generated from polysaccharide decomposition process. However, saccharide mapping was not widely applied in the polysaccharide analysis for lacking of systematic introduction. In this review, a detailed description of the establishment process of saccharide mapping, the pros and cons of downstream technologies, an overview of the application of saccharide mapping, and practical strategies were summarized. With the updating of the available downstream technologies, saccharide mapping had been expanding its scope of application to various kinds of polysaccharides. The process of saccharide mapping analysis included polysaccharides degradation and hydrolysates analysis, and the degradation process was no longer limited to acid hydrolysis. Some downstream technologies were convenient for rapid qualitative analysis, while others could achieve quantitative analysis. For the more detailed structure information could be provided by saccharide mapping, it was possible to improve the quality control of polysaccharides during preparation and application. This review filled the blank of basic information about saccharide mapping and was helpful for the establishment of a professional workflow for the saccharide mapping application to promote the deep study of polysaccharide structure.

Profiling of cool-season forage arabinoxylans via a validated HPAEC-PAD method

Cool-season pasture grasses contain arabinoxylans (AX) as their major cell wall hemicellulosic polysaccharide. AX structural differences may influence enzymatic degradability, but this relationship has not been fully explored in the AX from the vegetative tissues of cool-season forages, primarily because only limited AX structural characterization has been performed in pasture grasses. Structural profiling of forage AX is a necessary foundation for future work assessing enzymatic degradability and may also be useful for assessing forage quality and suitability for ruminant feed. The main objective of this study was to optimize and validate a high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method for the simultaneous quantification of 10 endoxylanase-released xylooligosaccharides (XOS) and arabinoxylan oligosaccharides (AXOS) in cool-season forage cell wall material. The following analytical parameters were determined or optimized: chromatographic separation and retention time (RT), internal standard suitability, working concentration range (CR), limit of detection (LOD), limit of quantification (LOQ), relative response factor (RRF), and quadratic calibration curves. The developed method was used to profile the AX structure of four cool-season grasses commonly grown in pastures (timothy, Phleum pratense L.; perennial ryegrass, Lolium perenne L.; tall fescue, Schedonorus arundinaceus (Schreb.) Dumort.; and Kentucky bluegrass, Poa pratensis L.). In addition, the cell wall monosaccharide and ester-linked hydroxycinnamic acid contents were determined for each grass. The developed method revealed unique structural aspects of the AX structure of these forage grass samples that complemented the results of the cell wall monosaccharide analysis. For example, xylotriose, representing an unsubstituted portion of the AX polysaccharide backbone, was the most abundantly-released oligosaccharide in all the species. Perennial rye samples tended to have greater amounts of released oligosaccharides compared to the other species. This method is ideally suited to monitor structural changes of AX in forages as a result of plant breeding, pasture management, and fermentation of plant material.

Berries in Microbiome-Mediated Gastrointestinal, Metabolic, and Immune Health

PURPOSE OF REVIEW

Current research has shown that berry-derived polymeric substrates that resist human digestion (dietary fibers and polyphenols) are extensively metabolized in the gastrointestinal tract dominated by microbiota. This review assesses current epidemiological, experimental, and clinical evidence of how berry (strawberry, blueberry, raspberry, blackberry, cranberry, black currant, and grapes) phytochemicals interact with the microbiome and shape health or metabolic risk factor outcomes.

RECENT FINDINGS

There is a growing evidence that the compositional differences among complex carbohydrate fractions and classes of polyphenols define reversible shifts in microbial populations and human metabolome to promote gastrointestinal health. Interventions to prevent gastrointestinal inflammation and improve metabolic outcomes may be achieved with selection of berries that provide distinct polysaccharide substrates for selective multiplication of beneficial microbiota or oligomeric decoys for binding and elimination of the pathogens, as well as phenolic substrates that hold potential to modulate gastrointestinal mucins, reduce luminal oxygen, and release small phenolic metabolites signatures capable of ameliorating inflammatory and metabolic perturbations. These mechanisms may explain many of the differences in microbiota and host gastrointestinal responses associated with increased consumption of berries, and highlight potential opportunities to intentionally shift gut microbiome profiles or to modulate risk factors associated with better nutrition and health outcomes.

Structures of the xyloglucans in the monocotyledon family Araceae (aroids)

The xyloglucans of all aquatic Araceae species examined had unusual structures compared with those of other non-commelinid monocotyledon families previously examined. The aquatic Araceae species Lemna minor was earlier shown to have xyloglucans with a different structure from the fucogalactoxyloglucans of other non-commelinid monocotyledons. We investigated 26 Araceae species (including L. minor), from five of the seven subfamilies. All seven aquatic species examined had xyloglucans that were unusual in having one or two of three features: < 77% XXXG core motif [L. minor (Lemnoideae) and Orontium aquaticum (Orontioideae)]; no fucosylation [L. minor (Lemnoideae), Cryptocoryne aponogetonifolia, and Lagenandra ovata (Aroideae, Rheophytes clade)]; and > 14% oligosaccharide units with S or D side chains [Spirodela polyrhiza and Landoltia punctata (Lemnoideae) and Pistia stratiotes (Aroideae, Dracunculus clade)]. Orontioideae and Lemnoideae are the two most basal subfamilies, with all species being aquatic, and Aroideae is the most derived. Two terrestrial species [Dieffenbachia seguine and Spathicarpa hastifolia (Aroideae, Zantedeschia clade)] also had xyloglucans without fucose indicating this feature was not unique to aquatic species.

Biorefinery of apple pomace: New insights into xyloglucan building blocks

Within the apple pomace biorefinery cascade processing framework aiming at adding value to an agroindustrial waste, after pectin recovery, this study focused on hemicellulose. The structure of the major apple hemicellulose, xyloglucan (XyG), was assessed as a prerequisite to potential developments in industrial applications. DMSO-LiCl and 4 M KOH soluble hemicelluloses from pectin-extracted apple pomace were purified by anion exchange chromatography. XyG structure was assessed by coupling xyloglucanase and endo-β-1,4-glucanase digestions to HPAEC and MALDI-TOF MS analyses. 71.9% of pomaces hemicellulose were recovered with starch. DMSO-LiCl and 4 M KOH soluble XyG exhibited Mw of 19 and 140 kDa, respectively. Besides the XXXG, XLXG, XXLG, XXFG, XLFG and XLLG structures, novel oligosaccharides with degree of polymerization of 6-10 were observed after xyloglucanase digestion. Cellobiose and cellotriose were revealed randomly distributed in XyG backbone and were more present in DMSO-LiCl soluble XyG. Residual pomace remains a potential source of other materials.

Chemical composition and technofunctional properties of carrot (Daucus carota L.) pomace and potato (Solanum tuberosum L.) pulp as affected by thermomechanical treatment

Fiber rich by-products derived from primary agri-food production such as carrot pomace and potato pulp are available in large quantities, but their functional properties do not necessarily meet the requirements for use in specific food applications. Thermomechanical treatment (extrusion) of carrot pomace and potato pulp changes both dietary fiber polysaccharide structures and technofunctionality of the materials. Solubility of dietary fiber constituents changes, resulting in higher levels of water- and ethanol-soluble poly-/oligosaccharides. On a structural level, particularly arabinans and galactans as neutral side chains of type I rhamnogalacturonan were degraded under thermomechanical stress. Galacturonic acid portions (preferably from homogalacturonan or rhamnogalacturonan I) and their degree of methylation were also negatively affected. On a functional level, water absorption of potato pulp increased up to three times following extrusion, whereas water absorption of carrot pomace decreased with extrusion processing. The observed, enhanced swelling behavior for extruded carrot pomace was accompanied by higher complex viscosity of the dispersions. Swelling of potato pulp particles increased largely (up to 25 times) following extrusion, resulting in highly viscous pastes. Phytochemicals were retained up to 50%, heat-induced contaminants were formed only to a small extent (up to 8.1 mg 5-hydroxymethylfurfural·kg− 1 dry matter for carrot pomace; up to 71 µg acrylamide·kg− 1 dry matter for potato pulp).

Graphical abstract

Structural Characterization of Dietary Fiber from Different Lupin Species (Lupinus sp.)

Dietary fiber fractions of whole seeds from different lupin species were structurally characterized. The low-molecular-weight soluble dietary fiber fraction contains mainly stachyose and verbascose. The soluble dietary fiber fraction is dominated by homogalacturonan and rhamnogalacturonan type I (RGI), with (arabino-)galactans and to a lesser portion arabinans as neutral RGI side chains. Arabinans are preferentially branched in position O2 as demonstrated by methylation analysis and an arabinan profiling approach. Insoluble dietary fiber is mainly composed of cellulose and pectins, but xylans and xyloglucans are present, too. Application of an enzymatic xyloglucan profiling approach demonstrated a substitution degree of 75% and proved the existence of fucosylated xyloglucans. Lignin of all lupin species was analyzed as being rich in guaiacyl units; however, the degree of lignification is low. Alcohol-insoluble residue polysaccharides from both seed coat and embryo/endosperm were analyzed separately, demonstrating tissue-related differences in the portions of cellulose and RGI.

A capillary electrophoresis method for the determination of soluble monosaccharides in Ginkgo biloba leaves

A method for the simultaneous determination of six monosaccharides by pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone and capillary electrophoresis was developed in this work. The derivatization (i.e., reaction temperature, capillary electrophoresis duration, and extraction number) and separation (i.e., pH and buffer concentration) conditions for capillary electrophoresis were optimized. Results showed that the limits of detection under optimal conditions were in the range of 0.036-0.35 mg/L with a mean correlation coefficient >0.99. The recoveries were in the range of 87.3-108.49%, and the relative standard deviations of intra- and inter-day variations were in the ranges of 2.2-3.8 and 3.2-5.0%, respectively. The method was successfully applied to the analysis of six free monosaccharides in three types of Ginkgo biloba leaves.