Pectic Polysaccharides Research Articles

Altering the water holding capacity of potato pulp via structural modifications of the pectic polysaccharides

Potato pulp is a low value agricultural side stream with great valorisation potential as prebiotic food ingredient. An interesting functionality different from other prebiotics is its high water holding capacity (WHC). This study aims at exploring the relationship between physical and enzymatic modifications in the potato pulp and its WHC. Different temperature treatments and storage conditions were found to have a great influence on the WHC, freezing decreasing the WHC the least (15%) compared to fresh pulp. Ultrasonication of frozen pulp increased its WHC by 32%, while it did not have an effect on fresh pulp. Of the various tested enzymes, only protease led to an increase in WHC of fresh pulp (by 48%). The WHC of frozen and dry pulp could not be positively influenced by enzymatic treatment. Structurally, the potato pulps with increased WHC exhibited a larger surface area and more flaky structure.

Barofractionation as an Innovative Method to Obtain Pectic Polysaccharides

An innovative method has been developed and an installation has been created for obtaining pectin polysaccharides in a dynamic mode under the influence of high pressure. The process of degradation of protopectin at various pH values pH of the hydrolyzing agent was studied using the example of sunflower baskets. It has been established that the use of the new method makes it possible to obtain high-quality target products with a high yield in gentle conditions. The possibility of combining the stages of hydrolysis-extraction and fractionation has been demonstrated, which makes it possible to control the process of obtaining pectic polysaccharides in the direction of obtaining substances with specified physicochemical parameters.

Cinnamomum burmannii decoction: A thickening and flavouring ingredient

Cinnamon is a spice widely used as a flavouring agent in foodstuffs. Despite its commercial availability and low cost, C. burmannii aqueous extracts obtained by decoction originate high viscous solutions (1545 cP) when compared with C. verum (51 cP), preventing its broad use by food industry. Following the hypothesis that cinnamon polysaccharides are responsible for this viscosity, in this work, the hot water-soluble polysaccharides from C. burmannii were structurally characterized, using C. verum for comparison. The results showed that C. burmannii had a higher content of branched arabinoxylans in relation to C. verum. The hot water-soluble polysaccharides from C. verum comprised also glucans, arabinogalactans, and pectic polysaccharides. The partial mild acid-hydrolysis performed to C. burmannii allowed to reach a viscosity value near to the C. verum solutions, keeping the characteristic aroma profile of cinnamon by the predominance of cinnamaldehyde and other varietal compounds, namely mono and sesquiterpenoids. Therefore, C. burmannii can be used as flavouring and thickening agent, whereas low viscosity products can be obtained by a partial acid-hydrolysis, contributing to its wide application in food industry.

Bell Peppers (Capsicum annum L.) Losses and Wastes: Source for Food and Pharmaceutical Applications.

Currently, the high added-value compounds contained in plant by-products and wastes offer a wide spectrum of opportunities for their reuse and valorization, contributing to the circular economy. The bell pepper (Capsicum annum L.) is an exotic vegetable with high nutritional value that, after processing, leaves wastes (peel, seeds, and leaves) that represent desirable raw material for obtaining phytochemical compounds. This review summarizes and discusses the relevant information on the phytochemical profile of bell peppers and their related biological properties as an alternative to revalorize losses and wastes from bell peppers for their application in the food and pharmaceutical industries. Bell pepper fruits, seeds, and leaves contain bioactive compounds (phenols, flavonoids, carotenoids, tocopherol, and pectic polysaccharides) that exhibit antioxidant, antibacterial, antifungal, immunosuppressive and immunostimulant properties, and antidiabetic, antitumoral and neuroprotective activities, and have a potential use as functional food additives. In this context, the revalorization of food waste is positioned as a technological and innovative research area with beneficial effects for the population, the economy, and the environment. Further studies are required to guarantee the safety use of these compounds and to understand their mechanisms of action.

Cannabis Glandular Trichome Cell Walls Undergo Remodeling to Store Specialized Metabolites.

The valuable cannabinoid and terpenoid metabolites of Cannabis sativa L. are produced by floral glandular trichomes. The trichomes consist of secretory disk cells, which produce the abundant lipidic metabolites, and an extracellular storage cavity. The mechanisms of apoplastic cavity formation to accumulate and store metabolites in cannabis glandular trichomes remain wholly unexplored. Here, we identify key wall components and how they change during cannabis trichome development. While glycome and monosaccharide analyses revealed that glandular trichomes have loosely bound xyloglucans and pectic polysaccharides, quantitative immunolabeling with wall-directed antibodies revealed precise spatiotemporal distributions of cell wall epitopes. An epidermal-like identity of early trichome walls matured into specialized wall domains over development. Cavity biogenesis was marked by separation of the subcuticular wall from the underlying surface wall in a homogalacturonan and α-1,5 arabinan epitope-rich zone and was associated with a reduction in fucosylated xyloglucan epitopes. As the cavity filled, a matrix with arabinogalactan and α-1,5 arabinan epitopes enclosed the metabolite droplets. At maturity, the disk cells' apical wall facing the storage cavity accumulated rhamnogalacturonan-I epitopes near the plasma membrane. Together, these data indicate that cannabis glandular trichomes undergo spatiotemporal remodeling at specific wall subdomains to facilitate storage cavity formation and metabolite storage.

Induction of Conjugation and Zygospore Cell Wall Characteristics in the Alpine Spirogyra mirabilis (Zygnematophyceae, Charophyta): Advantage under Climate Change Scenarios?

Extreme environments, such as alpine habitats at high elevation, are increasingly exposed to man-made climate change. Zygnematophyceae thriving in these regions possess a special means of sexual reproduction, termed conjugation, leading to the formation of resistant zygospores. A field sample of Spirogyra with numerous conjugating stages was isolated and characterized by molecular phylogeny. We successfully induced sexual reproduction under laboratory conditions by a transfer to artificial pond water and increasing the light intensity to 184 µmol photons m−2 s−1. This, however was only possible in early spring, suggesting that the isolated cultures had an internal rhythm. The reproductive morphology was characterized by light- and transmission electron microscopy, and the latter allowed the detection of distinctly oriented microfibrils in the exo- and endospore, and an electron-dense mesospore. Glycan microarray profiling showed that Spirogyra cell walls are rich in major pectic and hemicellulosic polysaccharides, and immuno-fluorescence allowed the detection of arabinogalactan proteins (AGPs) and xyloglucan in the zygospore cell walls. Confocal RAMAN spectroscopy detected complex aromatic compounds, similar in their spectral signature to that of Lycopodium spores. These data support the idea that sexual reproduction in Zygnematophyceae, the sister lineage to land plants, might have played an important role in the process of terrestrialization.

Systematic evaluation of a series of pectic polysaccharides extracted from apple pomace by regulation of subcritical water conditions

To investigate the influences of different subcritical water conditions on apple pomace pectic polysaccharides (APP) extraction, 20 samples were successfully prepared and systematically analyzed. At low temperature region (100–120 °C), extraction effect was predominant and extracted APP was high molecular weight, esterification degree and galacturonic acid content as well as light color. At middle temperature region (140 °C), the balance of extraction and degradation effects was reached and led to the highest APP yield (14.89%). At high temperature region (160–180 °C), degradation effect was predominant and led to serious degradation of APP and more extraction of co-extracts, which endowed the APP with low viscosity and good antioxidant activities in vitro. Overall, the relationship between different subcritical water conditions and APP properties are preliminarily illuminated, which not only provides a promising way for directed extraction of specific APP, but also promotes the potential application of subcritical water to commercial pectin.

Structure and rheology of pectic polysaccharides from baobab fruit and leaves

Linkage patterns and relaxation dynamics of baobab (Adansonia digitata) polysaccharides have been investigated by means of linkage analysis and rheometry. The fruit polysaccharide was mostly xylogalacturonan, with co-extracted α-glucan. The leaf polysaccharide consists predominantly of two domains, one branched at O-4 of the →2)-Rhap-(1→ residues and another branched at O-3 of the →4)-GalpA-(1→ backbone to single GlcpA-(1→ residues. Master curves of viscoelasticity of fruit polysaccharides manifested strong pH-dependency. At pH below the dissociation constant of galacturonic acid, dispersions showed liquid-like behaviour. In contrast, at neutral pH, a weak gel network formation was observed that destabilised rapidly under the influence of flow fields. The present work identifies xylogalacturonans from baobab fruit as polysaccharides with unique rheological characteristics that may point to new directions in food and pharmaceutical formulation.

Inhibitory effects of orally administered pectic polysaccharides extracted from the citrus Hallabong peel on lung metastasis

In this study, we investigated the anti-metastatic effect of the pectic polysaccharide HBE-0, extracted from peels of Hallabong, Korea citrus by pectinase digestion and ethanol precipitation. HBE-0 comprises 64.4% neutral sugars and 31.7% uronic acid including 14 types of monosaccharides. IL-6 and IL-12 were secreted in a dose-dependent manner by peritoneal macrophages stimulated with HBE-0. Intravenous administration of HBE-0 significantly augmented the cytolytic activity of NK cells. In lung metastasis assays using Colon26-M3.1 carcinoma cells, prophylactically intravenous administration of HBE-0 at a dose of 50 mg/kg showed up to 90% inhibitory effect on lung metastasis. Furthermore, NK cells depletion by anti-asialo-GM1 partially reduced the inhibitory effect of HBE-0 on lung metastasis. Further, oral administration of HBE-0 induced NK cell cytotoxicity and dose-dependently inhibited lung metastasis. These results suggest that HBE-0 isolated from Hallabong peels possesses anti-metastatic activity and supports its potential as a health-functional or pharmacological agent in commercial applications by increasing the high added-value of discarded agricultural byproducts.

Digestion of pectic polysaccharide from Brassica rapa L. in vitro and its effect on the intestinal microbiota in cyclophosphamide‐treated mice

AbstractIn this study, the digestion of pectic polysaccharide from Brassica rapa L. (BRP) in vitro and its effect on the intestinal microbiota in cyclophosphamide (Cy)‐treated mice were investigated. As a result, the molecular weight (Mw) of BRP was significantly decreased after simulated gastrointestinal digestion, and content of reducing sugars (CR) was significantly increased (P < 0.05), implying that BRP was gradually degraded under gastrointestinal digestion conditions in vitro. In vivo, both 50 or 200 mg kg−1·BW/d of BRP significantly improved SCFAs concentrations that decreased by Cy treatment (P < 0.05). Meanwhile, BRP enriched the alpha‐diversity of intestinal microbiota and altered the microbial composition with an increase of Lactobacillus and a decrease of Clostridium, Ruminococcus, Oscillospira (P < 0.05). Besides, BRP intervention was conducive to the recovery of mouse body weight, thymus and spleen indices, and contributed to improve the intestinal barrier.

Bioactive pectic polysaccharides from bay tree pruning waste: Sequential subcritical water extraction and application in active food packaging

The potential isolation of bio-active polysaccharides from bay tree pruning waste was studied using sequential subcritical water extraction using different time-temperature combinations. The extracted polysaccharides were highly enriched in pectins while preserving their high molecular mass (10–100 kDa), presenting ideal properties for its application as additive in food packaging. Pectin-enriched chitosan films were prepared, improving the optical properties (≥95% UV-light barrier capacity), antioxidant capacity (˃95% radical scavenging activity) and water vapor permeability (≤14 g·Pa−1·s−1·m−1·10−7) in comparison with neat chitosan-based films. Furthermore, the antimicrobial activity of chitosan was maintained in the hybrid films. Addition of 10% of pectins improved mechanical properties, increasing the Young's modulus 12%, and the stress resistance in 51%. The application of pectin-rich fractions from bay tree pruning waste as an additive in active food packaging applications, with triple action as antioxidant, barrier, and antimicrobial has been demonstrated.

Coffee Silver Skin: Chemical Characterization with Special Consideration of Dietary Fiber and Heat-Induced Contaminants.

Coffee silver skin is produced in large amounts as a by-product during the coffee roasting process. In this study, coffee silver skin of the species Coffea arabica L. and Coffea canephora Pierre ex A. Froehner as well as silver skin pellets produced in the coffee industry were characterized with respect to both nutritional value and potential heat-induced contaminants. Enzymatic-gravimetric/chromatographic determination of the dietary fiber content showed values ranging from 59 to 67 g/100 g with a comparably high portion of soluble fiber, whereas low molecular weight soluble fiber was not detected. Compositional and methylation analysis indicated the presence of cellulose and xylans in the insoluble dietary fiber fraction, whereas pectic polysaccharides dominate the soluble dietary fiber fraction. The protein content as determined by the Kjeldahl method was in the range of 18 to 22 g/100 g, and all essential amino acids were present in coffee silver skin; whereas fat contents were low, high ash contents were determined. Elemental analysis by inductively coupled plasma mass spectrometry (ICP-MS) showed the presence of macroelements in large amounts, whereas toxic mineral elements were only detected in trace amounts or being absent. Acrylamide was quantified with levels of 24–161 µg/kg. Although 5-hydroxymethylfurfural was detected, its concentration was below the limit of determination. Furfuryl alcohol was not detected.

Cell wall break down of pitanga fruit (Eugenia uniflora L.) is associated with pectic solubilisation and softening

SummaryPitanga fruit stands out for its exotic flavour and antioxidant properties. The objective of this work was to evaluate changes in the physical, chemical and biochemical variables of red pitanga variety, in four stages of development (green, yellow, orange and red) and associate them to the cell wall break down. Analysis of pH, titratable acidity, soluble solids, firmness, soluble pectin, pectinamethylesterase (PME), polygalacturonase (PG), cell wall swelling and microstructure were performed. pH and levels of soluble solids and soluble pectin increased, in addition to the cell wall swelling and reduction of firmness, throughout the development of pitanga. From the SEM, it was possible to observe the degradation of the fruit cell wall during ripening, suggesting mainly the degradation of pectic polysaccharides, verified by the solubilisation of these substances. PG and PME enzymes were not active, which suggests that other enzymes may be associated with the cell wall break down.

Effect of Sonication Treatment and Maceration Time in the Extraction of Polysaccharide Compounds during Red Wine Vinification.

The application of high-power ultrasounds (US) at 28 kHz to the crushed grapes and the use of different pomace contact times caused changes in the content and composition of monosaccharides and polysaccharides in the musts and wines. These differences were maintained from the moment of pressing (end of maceration) until the end of the alcoholic fermentation. The US increased the content of monosaccharides and polysaccharides in the musts by facilitating their extraction from the solid parts during maceration. The application of medium maceration time (3 days) to sonicated grapes led to an extraction of polysaccharides rich in arabinose and galactose, rhamnogalacturonan type II (RG-II) and mannoproteins (MP), similar to that observed in the control wines made with an extended maceration of 7 days (968.21 vs. 1029.45; 895.04 vs. 1700.50; 356.81 vs. 343.95, respectively). This fact was attributed to a higher extraction in the must during the sonication process and to an important release of pectic polysaccharides during the pressing of the sonicated pomace, which is reported here for the first time. Therefore, the US technology could be useful for increasing the polysaccharide content in the wines or for reducing the maceration time needed to achieve certain levels of wine polysaccharides.

Functional fermented beverage made with apple, tibicos, and pectic polysaccharides from prickly pear ( Opuntia ficus‐indica L. Mill) peels

The extraction of pectic polysaccharides from Opuntia ficus-indica peels was performed by two methods: acid hydrolysis (0.1N HCl; 70% ethanol, pH = 1.5), by the use of different ratios of sample/solvent (1:5, 1:7 wt/vol) at 90 ± 0.1℃ for 40 min and ultrasound-assisted extraction with amplitude of 30%, nominal power of 125 W, at three times (10, 20, 30 min), and 45 ± 0.1℃. The yield, degree of methoxylation, and galacturonic acid were evaluated. The pectic polysaccharides obtained from the peels of Opuntia showed weak gel behavior. The symbiotic product was elaborated with apple juice, tibicos as a starter culture, pectic polysaccharides at two concentrations (7.5 and 10% wt/vol), and cane sugar (60% wt/vol). The storage stability at relative humidity 75% and temperature (7, 25, and 40℃) along 42 days was evaluated. The product was microbiologically and mechanically stable for 42 days at 7℃. Novelty impact statement The use of ultrasound improves the polygalacturonic acid extraction from pectic polysaccharides of prickly pear peels; this material could be used to obtain a fermented product by tibicos and apple with good mechanical and microbiological stability until 42 days at 7℃.

Effects of ultra-high pressure enzyme extraction on characteristics and functional properties of red pitaya (Hylocereus polyrhizus) peel pectic polysaccharides

An efficient ultra-high pressure (UP) compound enzyme extraction (UPEE) technology was used to extract and modify polysaccharides (U-RPPPs) from red Pitaya (Hylocereus polyrhizus) peels (RPPs), contributing to the increase yield and antioxidant activity as well as improvement of polysaccharides’ physicochemical and functional characteristics. Three polysaccharides (RPPP-1, RPPP-2 and RPPP-3) were isolated and purified from U-RPPPs by using a combination of ultra-filtration and gel permeation chromatography. Compared with heat reflux extraction polysaccharide (H-RPPPs), the extraction yield, uronic acid content (UAC), total phenols content (TPC), total flavonoids content (TFC), water solubility (WS), water holding capacity (WHC), oil holding capacity (OHC) of U-RPPPs were increased by 93.45%, 53.57%, 19.37%, 40.37%, 0.87%, 42.38%, 18.85% respectively, and molecular weight (MW), degree of esterification (DE) and protein content (PC) were decreased by 27.89%, 38.85% and 12.20% respectively, which significantly enhanced antioxidant activities including FRAP by 44.26%, DPPH· by 37.50%, ·OH by 26.59% and ·O2− by 27.27%, respectively. Among the three fractions, RPPP-1 had the lowest MW and DE, the highest contents of TPC, TFC, galacturonic acid (GalA), galactose (Gal) and rhamnose (Rha), exhibited good WS, WHC, favorable thermal stability, and showed the best antioxidant activities in a dose-dependent manner. These findings demonstrated that UPEE was an effective method to increase the extraction yields, improve the functional properties and bioactivities of pectic polysaccharides, which has enormous potential in the food industries.

Root-knot nematode chemotaxis is positively regulated by l-galactose sidechains of mucilage carbohydrate rhamnogalacturonan-I.

Root-knot nematodes (RKNs) are plant parasites and major agricultural pests. RKNs are thought to locate hosts through chemotaxis by sensing host-secreted chemoattractants; however, the structures and properties of these attractants are not well understood. Here, we describe a previously unknown RKN attractant from flaxseed mucilage that enhances infection of Arabidopsis and tomato, which resembles the pectic polysaccharide rhamnogalacturonan-I (RG-I). Fucose and galactose sidechains of the purified attractant were found to be required for attractant activity. Furthermore, the disaccharide α-l-galactosyl-1,3-l-rhamnose, which forms the linkage between the RG-I backbone and galactose sidechains of the purified attractant, was sufficient to attract RKN. These results show that the α-l-galactosyl-1,3-l-rhamnose linkage in the purified attractant from flaxseed mucilage is essential for RKN attraction. The present work also suggests that nematodes can detect environmental chemicals with high specificity, such as the presence of chiral centers and hydroxyl groups.

Defined shear and heat treatment of apple pomace: impact on dietary fiber structures and functional properties

Food by-products can be modified by extrusion processing. However, the impact of thermal and mechanical stress, respectively, on the structure and thus functional properties of dietary fiber-rich food by-products is still unknown. In the extrusion process, thermal and mechanical stress are coupled, not constant, and difficult to measure or calculate. Thus, their influence on structural changes and functional properties cannot be evaluated separately. In this work, a specific shear cell, denoted by closed cavity rheometer, was used to treat apple pomace with defined thermal and/or mechanical stress. Dietary fiber composition and fiber polysaccharide structures appeared to be more susceptible to high temperatures than mechanical stress. With increasing temperature (and mechanical stress) soluble and low-molecular-weight soluble dietary fiber contents increased, whereas insoluble fiber contents decreased. Arabinans as rhamnogalacturonan type I polysaccharides and galacturonic acid containing pectic polysaccharides were identified as being most susceptible to degradation under these conditions. Furthermore, the defined treatment affected the functional properties. Although changes in the water solubility index (WSI) and/or the water absorption index (WAI) were not detected up to 90 °C, WSI and WAI decreased significantly at a treatment temperature of 120 °C. However, at very high temperatures (160 °C), WSI and WAI increased. The application of shear and longer treatment times resulted in higher WSI values and complex viscosities as compared to low shear stress.Graphic abstract

Protocols for isolating and characterizing polysaccharides from plant cell walls: a case study using rhamnogalacturonan-II

BackgroundIn plants, a large diversity of polysaccharides comprise the cell wall. Each major type of plant cell wall polysaccharide, including cellulose, hemicellulose, and pectin, has distinct structures and functions that contribute to wall mechanics and influence plant morphogenesis. In recent years, pectin valorization has attracted much attention due to its expanding roles in biomass deconstruction, food and material science, and environmental remediation. However, pectin utilization has been limited by our incomplete knowledge of its structure. Herein, we present a workflow of principles relevant for the characterization of polysaccharide primary structure using nature’s most complex polysaccharide, rhamnogalacturonan-II (RG-II), as a model.ResultsWe outline how to isolate RG-II from celery and duckweed cell walls and from red wine using chemical or enzymatic treatments coupled with size-exclusion chromatography. From there, we applied mass spectrometry (MS)-based techniques to determine the glycosyl residue and linkage compositions of the intact RG-II and derived oligosaccharides including special considerations for labile monosaccharides. In doing so, we demonstrated that in the duckweed Wolffiella repanda the arabinopyranosyl (Arap) residue of side chain B is substituted at O-2 with rhamnose. We used electrospray-MS techniques to identify non-glycosyl modifications including methyl-ethers, methyl-esters, and acetyl-esters on RG-II-derived oligosaccharides. We then showed the utility of proton nuclear magnetic resonance spectroscopy (1H-NMR) to investigate the structure of intact RG-II and to complement the RG-II dimerization studies performed using size-exclusion chromatography.ConclusionsThe complexity of pectic polysaccharide structures has hampered efforts aimed at their valorization. In this work, we used RG-II as a model to demonstrate the steps necessary to isolate and characterize polysaccharides using chromatographic, MS, and NMR techniques. The principles can be applied to the characterization of other saccharide structures and will help inform researchers on how saccharide structure relates to functional properties in the future.

Pectin recovery from apple pomace: physico‐chemical and functional variation based on methyl‐esterification

SummaryThis study explored the valorisation of apple pomace by extracting pectin with both high and low degrees of esterification (DM). Two types of pectin were extracted with a DM of 43.29% being low methoxyl (LM) pectic polysaccharide and high methoxyl (HM) pectin with a DM of 65.88%. HM pectin was characterised by a WHC and OHC of 1.3 g g−1 and 0.4 g g−1, respectively, compared to 0.32 g g−1 and 0.14 g g−1, respectively, for LM pectic polysaccharide. HM pectin possessed greater purity indicated by 69.18% GalA, whereas LM pectic polysaccharide possessed 41.26% GalA. HM pectin revealed better functionality in terms of high emulsifying activity which was concentration‐dependent, and emulsion stability than LM pectic polysaccharide. The solubility of HM pectin was 90.8%, which is preferable for various industrial applications. LM pectic polysaccharide was characterised by a higher % radical‐scavenging activity in a concentration‐dependent manner. XRD analysis revealed LM pectic polysaccharide to possess higher crystallinity (53%) and SEM analysis revealed its surface to be rough and coarse.