Pectic Polysaccharides Research Articles

Oryza sativa PECTIN DEFECTIVE TAPETUM1 affects anther development through a pectin-mediated signaling pathway in rice.

Galacturonosyltransferase (GalAT) is required for the synthesis of pectin, an important component of plant cell walls that is also involved in signal transduction. Here, we describe the rice (Oryza sativa) male-sterile mutant O. sativa pectin-defective tapetum1 (ospdt1), in which GalAT is mutated. The ospdt1 mutant exhibited premature programmed cell death (PCD) of the tapetum and disordered pollen walls, resulting in aborted pollen grains. Pectin distribution in the anther sac was comparable between the mutant and the wild-type, suggesting that the structural pectin was not dramatically affected in ospdt1. Wall-associated kinases are necessary for the signal transduction of pectin, and the intracellular distribution of O. sativa indica WALL-ASSOCIATED KINASE1 (OsiWAK1), which binds pectic polysaccharides to its extracellular domain, was affected in ospdt1. OsiWAK1 RNA interference lines exhibited earlier tapetal PCD, similar to ospdt1. Furthermore, overexpression of OsiWAK1 in ospdt1 lines partially rescued the defects observed in ospdt1, suggesting that OsiWAK1 plays pivotal roles in the function of OsPDT1. These results suggest that the mutation of OsPDT1 does not dramatically affect structural pectin but affects components of the pectin-mediated signaling pathway, such as OsiWAK1, and causes male sterility.

Structural Characterization of a Low Molecular Weight HG-Type Pectin From Gougunao Green Tea.

Tea is a popular beverage with a long history of safe and healthy use. Tea polysaccharide is a bioactive component extracted from tea, which has attracted more and more attention in recent decades. In this article, an acidic polysaccharide Gougunao tea polysaccharide (GPS) was isolated from Gougunao green tea by hot water extraction and ethanol precipitation. After purification by a diethylaminoethyl (DEAE) Sepharose Fast Flow column and a Sephacryl S-400 column, several homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) fractions were obtained. Fraction GPS2b with the highest yield was selected for structural characterization by methylation and nuclear magnetic resonance (NMR) analysis. GPS2b was found to be an HG-type pectic polysaccharide (degree of methyl esterification [DE], 51.6%) with low molecular weight (Mw, 36.8 kDa). It was mainly composed of →4)-α-GalpA- (1→ and →4)-α-GalpA-6-OMe-(1→. In addition, a minor highly branched RG-I domain was identified in this fraction. The investigation of structural features of tea polysaccharides can provide insights to understand their structure-bioactivity relationship.

Impact of thermally induced wall breakage on the structural properties of water-soluble polysaccharides in chickpeas

The present work aimed to elucidate the influence of wall breakage induced by thermal processing on the molecular, structural, and antioxidant activities of water-soluble polysaccharides in chickpeas. Different extents of cell wall disruption were observed by fluorescence microscopy in chickpea cotyledons. Moreover, a decreasing fluorescence intensity of cell wall fragments was observed in the flour residues upon heat fluidization, autoclaving, and microwave heating, and the polysaccharide extraction rates were increased by 31.47%, 25.52%, and 9.79%, respectively. Furthermore, WPUCP, WPHCP, WPMCP, and WPACP (water-soluble polysaccharides from unprocessed, heat fluidized, microwaved, and autoclaved chickpeas, respectively) were RG-I (rhamnogalacturonan-I)-enriched pectic polysaccharides composed of galactose, arabinose, galacturonic acid, and rhamnose. After chickpea thermal processing, the degrees of branching decreased to 2.87, 3.79, and 2.53 in WPHCP, WPMCP, and WPACP, respectively, and the molecular weights were reduced by 46.46%, 24.83%, and 59.91%, respectively. Structural analysis showed that the semicrystalline regions of WPHCP, WPMCP, and WPACP were slightly damaged without changing the functional groups, but their thermal stability decreased. Interestingly, WPACP formed an ordered conformation (microporous network structure) through the formation of hydrogen bonds. Moreover, the antioxidant activities of WPHCP, WPMCP, and WPACP were enhanced, and the strongest radical scavenging activity was observed for WPHCP.

Chain conformations and steady-shear viscosity properties of pectic polysaccharides from apple and tomato.

In this study, apple pectin (AP) and tomato pectin (TP) were demonstrated to be a high-ester (74.8%) polysaccharide with the weight-average molecular weight (Mw ) of∼243kDa and a low-ester (45.9%) polysaccharide with the Mw of∼19kDa, respectively. The semi-rigid chain conformations of pectic polysaccharides in NaNO3 aqueous solution were deduced according to the Smidsrød "B values" of AP (0.025) and TP (0.029), while AP and TP exhibited higher stiffness in water due to the electric repulsion of carboxyl groups, which was visually observed by AFM images. Under steady shear, the shear-thickening behaviors of AP and TP in NaNO3 aqueous solutions were observed in the shear rate range of<1s-1, which were attributed to the disruption of the ordered arrangement induced by semi-rigid pectin chains into randomly entangled structure by weak shear force. AP exhibited stronger shear-thickening behavior due to the formation of more entanglements resulted from the higher Mw and longer side chains highly branched at rhamngalacturonan region. This study provides the scientific basis for the construction of the relationship of steady-shear property with chain conformation and molecular weight of pectin.

Comparative study of water-soluble polysaccharides isolated from leaves and roots of Isatis indigotica Fort.

Water-soluble polysaccharides were isolated from the leaves and roots of Isatis indigotica Fort., and their structural features were studied and compared. One neutral polysaccharide fraction (WFIP-N) and three pectin fractions (WFIP-A-A, WFIP-A-B and WFIP-A-C) were obtained from the leaves, and one neutral polysaccharide fraction (WRIP-N) and two pectin fractions (WRIP-A-A and WRIP-A-B) were obtained from the roots. WFIP-A-B (Mw = 34.6 kDa) and WRIP-A-B (Mw = 29.9 kDa) were the major pectic polysaccharides. Monosaccharide composition, FT-IR, enzymatic hydrolysis, NMR and methylation analysis indicated that both WFIP-A-B and WRIP-A-B are composed of rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II) and homogalacturonan (HG) domains with mass ratios of 1.5:1.0:0.4 and 0.3:1.0:1.7, respectively. WFIP-A-B and WRIP-A-B were found to be rich in RG-I and HG domains, respectively, and mainly contained type II arabinogalactan (AG-II) and α-L-1,5-arabinan side chains, but those in WRIP-A-B were more numerous and longer. Our results provide structural features and differences between these polysaccharides which will help to elucidate their functional differences.

Pectic polysaccharides ameliorate the pathology of ulcerative colitis in mice by reducing pyroptosis.

BackgroundUlcerative colitis (UC) is an inflammatory bowel disease which seriously affects the quality of life of patients. There has been an increasing amount of research related to the therapeutic effects and mechanisms of natural plant substances in the treatment of recurrent UC. Rauwolfia verticillata var. Hainanensis is a medicinal plant that is native to Hainan Island, China. Some studies have documented that pectic polysaccharides (PPs) from Rauvolfia inhibited the progression of colon ulcers. However, their mechanisms of action have not been established. Studies have revealed that suppressing pyroptosis can attenuate the damage of experimental colitis. However, it is unclear whether PPs from Rauvolfia verticillata inhibit inflammation through pyroptosis. This study investigated the effects and potential mechanisms of PPs extracted from Rauvolfia verticillata on experimental UC in mice.MethodsMale C57 mice (6–8 weeks old) were allocated into the control group, the dextran sulfate sodium (DSS)-induced UC model group (DSS group), or the DSS with pectic polysaccharides treatment group (DSS + PP group). The body weights, rectal bleeding, and stool consistencies in the mice were observed, and the disease activity index (DAI) score was calculated. Colon tissues were collected for pathological analysis by histological hematoxylin and eosin (H&E) staining. The levels of caspase-1 and interleukin (IL)-1β were detected by immunohistochemistry. Pyroptosis was assessed by transmission electron microscopy.ResultsUC in mice induced by DSS resulted in decreased general physical activity and body weight, increased DAI score, significant histological changes, inhibited caspase-1 and IL-1β expression, and promoted pyroptosis. These DSS-induced changes could be partially ameliorated by administration of PP.ConclusionsPPs exerted an ameliorative effect on DSS-induced UC in mice by reducing pyroptosis.

Composition and yield of non-cellulosic and cellulosic sugars in soluble and particulate fractions during consolidated bioprocessing of poplar biomass by Clostridium thermocellum

BackgroundTerrestrial plant biomass is the primary renewable carbon feedstock for enabling transition to a sustainable bioeconomy. Consolidated bioprocessing (CBP) by the cellulolytic thermophile Clostridium thermocellum offers a single step microbial platform for production of biofuels and biochemicals via simultaneous solubilization of carbohydrates from lignocellulosic biomass and conversion to products. Here, solubilization of cell wall cellulosic, hemicellulosic, and pectic polysaccharides in the liquor and solid residues generated during CBP of poplar biomass by C. thermocellum was analyzed.ResultsThe total amount of biomass solubilized in the C. thermocellum DSM1313 fermentation platform was 5.8, 10.3, and 13.7% of milled non-pretreated poplar after 24, 48, and 120 h, respectively. These results demonstrate solubilization of 24% cellulose and 17% non-cellulosic sugars after 120 h, consistent with prior reports. The net solubilization of non-cellulosic sugars by C. thermocellum (after correcting for the uninoculated control fermentations) was 13 to 36% of arabinose (Ara), xylose (Xyl), galactose (Gal), mannose (Man), and glucose (Glc); and 15% and 3% of fucose and glucuronic acid, respectively. No rhamnose was solubilized and 71% of the galacturonic acid (GalA) was solubilized. These results indicate that C. thermocellum may be selective for the types and/or rate of solubilization of the non-cellulosic wall polymers. Xyl, Man, and Glc were found to accumulate in the fermentation liquor at levels greater than in uninoculated control fermentations, whereas Ara and Gal did not accumulate, suggesting that C. thermocellum solubilizes both hemicelluloses and pectins but utilizes them differently. After five days of fermentation, the relative amount of Rha in the solid residues increased 21% indicating that the Rha-containing polymer rhamnogalacturonan I (RG-I) was not effectively solubilized by C. thermocellum CBP, a result confirmed by immunoassays. Comparison of the sugars in the liquor versus solid residue showed that C. thermocellum solubilized hemicellulosic xylan and mannan, but did not fully utilize them, solubilized and appeared to utilize pectic homogalacturonan, and did not solubilize RG-I.ConclusionsThe significant relative increase in RG-I in poplar solid residues following CBP indicates that C. thermocellum did not solubilize RG-I. These results support the hypothesis that this pectic glycan may be one barrier for efficient solubilization of poplar by C. thermocellum.

Homogalacturonan from squash: Characterization and tau-binding pattern of a sulfated derivative

A pectic polysaccharide (WAP) was isolated from squash and identified as a homogalacturonan with a molecular mass of 83.2 kDa by GPC, monosaccharide composition analysis, FT-IR and NMR spectra. Sulfation modification of WAP was carried out and a sulfated derivative (SWAP) was obtained with a substitution degree of 1.81. The NMR spectrum indicated that the sulfation modification mainly occurred at the C-2 and C-3 positions of galacturonan residues. The binding pattern of SWAP to tau K18 protein was observed in 2D 1H15N HSQC spectra of tau, which resembled the tau-heparin interaction, with R2 domain as the major binding region. These results suggest that SWAP has the potential to act as a heparin mimic to inhibit the transcellular spread of tau; thus natural polysaccharide from squash may be developed into therapies for AD and related tauopathies.

A novel mitochondrial protein is required for cell wall integrity, auxin accumulation and root elongation in Arabidopsis under salt stress

Maintenance of root elongation is beneficial for the growth and survival of plants under salt stress, but currently the cellular components involved in the regulation of root growth under high salinity are not fully understood. In this study, we identified an Arabidopsis mutant, rres1, which exhibited reduced root elongation under treatment of a variety of salts, including NaCl, NaNO3, KCl, and KNO3. RRES1 encodes a novel mitochondrial protein and its molecular function is still unknown. Under salt stress, the root meristem length was shorter in the rres1 mutant compared to the wild type, which was correlated with a reduced auxin accumulation in the mutant. Reactive oxygen species (ROS), as important signals that regulate root elongation, were accumulated to higher levels in the rres1 mutant than the wild type after salt treatment. Measurement of monosaccharides in the cell wall showed that arabinose and xylose contents were decreased in the rres1 mutant under salt stress, and application of boric acid, which is required for the crosslinking of pectic polysaccharide rhamnogalacturonan-II (RG-II), largely rescued the root growth arrest of the rres1 mutant, suggesting that RRES1 participates in the maintenance of cell wall integrity under salt stress. GUS staining assay indicated that the RRES1 gene was expressed in leaves and weakly in root tip under normal conditions, but its expression was dramatically increased in leaves and roots after salt treatment. Together, our study reveals a novel mitochondrial protein that regulates root elongation under salt stress via the modulation of cell wall integrity, auxin accumulation, and ROS homeostasis.

Chemical elucidation and rheological properties of a pectic polysaccharide extracted from Citrus medica L. fruit residues by gradient ethanol precipitation.

Citron (Citrus. medica L.) fruits are commonly utilized in the production of essential oil, therefore, the fruits residues turn out to be industrial byproducts. In the present study, a crude polysaccharide was extracted from citron fruit residues by hot water extraction and precipitation of ethanol (95%), after deproteinization, a major polysaccharide component (CMLP-2) was obtained by gradient ethanol precipitation (20%-80%). The physicochemical properties of CMLP-2 such as surface morphology, functional groups, and thermostability were examined by FT-IR spectroscopy, SEM, and thermogravimetric analysis. Moreover, the chemical structure of CMLP-2 was elucidated that CMLP-2 is an acidic pectic polysaccharide consisting of arabinose (Ara), galacturonic acid (GalA), and rhamnose (Rha) in a molar ratio of 4:2:1 with a molecular weight of 202.18kDa. CMLP-2 is a novel pectic polysaccharide rich in rhamnogalacturonan I (RG-I). Moreover, rheological tests revealed that CMLP-2 solution is pseudoplastic and temperature resistant. The result could be a good basis for the utilization of Citrus medica L. fruits residues as plant-derived food additive.

Mechanism of viscosity reduction of okra pectic polysaccharide by ascorbic acid

In this work, effects of ascorbic acid (AH2) treatment on the viscosity and structural properties of okra pectic polysaccharide (OPP) and its mechanism were investigated. Results showed that AH2 could decrease the apparent viscosity of OPP, and the reducing ability was promoted by high temperature and the addition of Fe2+, Cu2+ or H2O2. The molecular weight was significantly decreased with increasing AH2 concentration, but it had little effects on the monosaccharide composition, glycosidic linkages, infrared characteristics, and morphology of OPP after AH2 incubation. Hydroxyl radicals were generated during the incubation, which can be activated by introducing Fe2+, Cu2+ or H2O2. In summary, the viscosity reduction of OPP induced by AH2 was related to the formation of hydroxyl radicals. The present study provides some recommendations for the application of OPP in food and other products containing AH2.

A DE1 BINDING FACTOR 1-GLABRA2 module regulates rhamnogalacturonan I biosynthesis in Arabidopsis seed coat mucilage.

The mucilage surrounding hydrated Arabidopsis thaliana seeds is a specialized extracellular matrix composed mainly of the pectic polysaccharide rhamnogalacturonan I (RG-I). Although, several genes responsible for RG-I biosynthesis have been identified, the transcriptional regulatory mechanisms controlling RG-I production remain largely unknown. Here we report that the trihelix transcription factor DE1 BINDING FACTOR 1 (DF1) is a key regulator of mucilage RG-I biosynthesis. RG-I biosynthesis is significantly reduced in loss-of-function mutants of DF1. DF1 physically interacts with GLABRA2 (GL2) and both proteins transcriptionally regulate the expression of the RG-I biosynthesis genes MUCILAGE MODIFIED 4 (MUM4) and GALACTURONOSYLTRANSFERASE-LIKE5 (GATL5). Through chromatin immunoprecipitation-quantitative PCR and transcriptional activation assays, we uncover a cooperative mechanism of the DF1-GL2 module in activating MUM4 and GATL5 expression, in which DF1 binds to the promoters of MUM4 and GATL5 through interacting with GL2 and facilitates the transcriptional activity of GL2. The expression of DF1 and GL2 is directly regulated by TRANSPARENT TESTA GLABRA2 (TTG2) and, in turn, DF1 directly represses the expression of TTG2. Taken together, our data reveal that the transcriptional regulation of mucilage RG-I biosynthesis involves a regulatory module, comprising DF1, GL2, and TTG2.

Structure and antiviral activity of a pectic polysaccharide from the root of Sanguisorba officinalis against enterovirus 71 in vitro/vivo

The increasing prevalence and pandemic risk of viral diseases warrant the development of safe and effective treatments. In this study, we aimed to elucidate the structure and anti-enterovirus 71 (EV71) effects of polysaccharides isolated from the roots of Sanguisorba officinalis (SO), traditionally used for infectious diseases. The purified polysaccharide (S-a3) was a homogenous macromolecule (260.4 kDa) with a concave and porous surface. Linkage and NMR analyses confirmed that S-a3 is a polysaccharide interlinked with homogalacturonan, rhamnogalacturonan-I, 1,4-α-glucan, and arabinogalactan. S-a3 significantly inhibited cell death and viral gene expression in EV71-infected Vero cells, and alleviated EV71-induced body weight loss, death, and paralysis in the hSCARB2-transgenic mouse model. The effective dose of S-a3 was non-toxic to cells and mice. The antiviral mechanism of S-a3 was associated with the disruption of EV71 attachment to host cells. Our findings demonstrate that polysaccharides from SO can be a safe and effective treatment for EV71 infection.

Optimization of high-pressure processing-assisted extraction of pectic polysaccharides from three berries

Abstract Background and objectives High-pressure processing (HPP) is a promising assistive method to extract pectic polysaccharides with high rhamnogalacturonan I (RG-I) domain and berries are sources of such pectic polysaccharides. This study extracts pectic polysaccharides from goji berry, raspberry, and cranberry, examines how HPP influences the pectic polysaccharide structure of three berries, and provides a basis for the extraction and modification of pectic polysaccharides with specific structure and bioactivity. Materials and methods An orthogonal test was performed to optimize the HPP-assisted alkali method to extract the high yield and high RG-I content pectic polysaccharides from three berries. Structural information of pectic polysaccharides extracted by the HPP method and conventional methods were compared from the perspectives of monosaccharide composition, molecular weight, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. Results For raspberry, the optimal conditions consisted of a pressure of 500 MPa, a pH of 13, and a pressure-holding time of 12 min, while the optimal conditions for goji berry and cranberry were both 400 MPa, pH 13, and 15 min. Under the optimal conditions, the yields for goji berry, raspberry, and cranberry were 10.49%, 16.63%, and 17.52%, respectively, and RG-I contents were 81.85%, 83.30%, and 63.22%, respectively. HPP showed an effect to degrade homogalacturonan backbones and side chains and increase the RG-I content to some extent. Conclusion HPP-assisted alkali method was revealed to be an efficient method to extract high RG-I content pectic polysaccharides, especially for cranberry, and was a potential method to modify pectic polysaccharide structure in a certain way.

Partial Characterization and Combination Therapy with a Pectic Polysaccharide from Semi-ripe Bael (Aegle marmelos) fruit in a Murine Model of Visceral Leishmaniasis

Partial Characterization and Combination Therapy with a Pectic Polysaccharide from Semi-ripe Bael (Aegle marmelos) fruit in a Murine Model of Visceral Leishmaniasis

Physicochemical and Functional Properties of Pectic Polysaccharides Extracted with Four Different Chelators from Sesame Hull

Physicochemical and Functional Properties of Pectic Polysaccharides Extracted with Four Different Chelators from Sesame Hull

Increasing RG-I content and lipase inhibitory activity of pectic polysaccharides extracted from goji berry and raspberry by high-pressure processing

The impact of high-pressure processing (HPP) extraction on the structural, rheological, and functional properties of goji berry and raspberry pectic polysaccharides were investigated under acidic and alkaline conditions. These properties were compared with those of pectic polysaccharides extracted by conventional hot-acid and cold-alkali methods. Extraction yield, molecular weight, rheological behavior, and antioxidant activity of pectic extracts depended on the source materials of extraction. The solvent pH was the driving factor for the degree of esterification, as revealed by NMR and FTIR analysis. Monosaccharide composition was the primary variable between the extracts. The hot-acid extraction led to the highest galacturonic acid (GalA) contents, 46.9% for goji berry and 65.2% for raspberry, indicating the prevalence of homogalacturonans (HG) regions. HPP-assisted acidic/alkaline extractions gave rise to higher rhamnogalacturonan-I (RG-I) regions, pointing to the prevalence of hairy regions. The antioxidant activity of raspberry extracts was significantly (P ≤ 0.05) higher than goji berry extracts. The higher amount of RG-I may determine the higher antioxidant activity of raspberry pectic polysaccharides. The correlation between structural parameters and the lipase inhibitory activity also revealed that the higher lipase inhibitory activity of pectic polysaccharides is mostly correlated with the higher content of RG-I (r = 0.9259, P = 0.00033). Thus, HPP-assisted extraction may intensify the lipase inhibitory activity of pectic polysaccharides by increasing their RG-I content.

Structure and fermentation characteristics of five polysaccharides sequentially extracted from sugar beet pulp by different methods

Pectic polysaccharides can serve as the best alternative for prebiotics, as they can be fermented in the gut by the microbiota. Many reports suggest that pectic polysaccharides' fermentation characteristics are superior to commercially available prebiotics as Inulin. However, these researches have focused on commercial pectin commonly extracted from apples or citrus, while pectins can exhibit complex and diverse structures. In this study, we extracted and characterized five structurally different polysaccharides from sugar beet pulp by water, 1,2-Cyclohexanediaminetetraacetic acid (CDTA), sodium carbonate, and sodium hydroxide, and then assessed their impacts on the human fecal microbiome. CDTA-soluble fraction and sodium carbonate-soluble fraction were identified as pectic polysaccharides, while water-soluble fraction and sodium hydroxide-soluble fractions were rich in the arabinose side chain. All polysaccharides were fermented more easily than inulin. Some neutral sugars were more easily fermented than acid sugar, and arabinose may be the first monosaccharide to be utilized by the microbiota, followed by glucose, fucose and galacturonic acid. After 48h of fermentation, some health-promoting bacteria like Faecalibacterium, Bifidobacterium, Lactobacillus, Blautia, and Prevotella increased, while some pathogenic bacteria like Fusobacterium, Sutterella, and Dorea decreased in all polysaccharides and Inulin. Hereby, through the study of the correlation between monosaccharide composition and microbiota, we showed that monosaccharide composition might be a critical structural feature linked to the polysaccharide-microbiota modulating effect. This could be helpful to have a criterion to choose the polysaccharides to better modulate the microbiota.

The Antidiabetic Effect of Grape Pomace Polysaccharide-Polyphenol Complexes.

Type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic metabolic diseases of the 21st century. Nevertheless, its prevalence might be attenuated by taking advantage of bioactive compounds commonly found in fruits and vegetables. This work is focused on the recovery of polyphenols and polysaccharide–polyphenol conjugates from grape pomace for T2DM management and prevention. Bioactives were extracted by solid–liquid extraction and by pressurized hot water extraction (PHWE). Polyphenolic fraction recovered by PHWE showed the highest value for total phenolic content (427 μg GAE.mg−1), mainly anthocyanins and proanthocyanidins, and higher antioxidant activity compared to the fraction recovered by solid–liquid extraction. Polysaccharide–polyphenol conjugates comprehended pectic polysaccharides to which approximately 108 μg GAE of phenolic compounds (per mg fraction) were estimated to be bound. Polyphenols and polysaccharide–polyphenol conjugates exhibited distinct antidiabetic effects, depending on the extraction methodologies employed. Extracts were particularly relevant in the inhibition of a-glucosidase activity, with free polyphenols showing an IC50 of 0.47 μg.mL−1 while conjugates showed an IC50 of 2.7, 4.0 and 5.2 μg.mL−1 (solid–liquid extraction, PHWE at 95 and 120 °C, respectively). Antiglycation effect was more pronounced for free polyphenols recovered by PHWE, while the attenuation of glucose uptake by Caco-2 monolayers was more efficient for conjugates obtained by PHWE. The antidiabetic effect of grape pomace bioactives opens new opportunities for the exploitation of these agri-food wastes in food nutrition, the next step towards reaching a circular economy in grape products.

ISOLATION AND PHYSICOCHEMICAL CHARACTERIZATION OF PECTIN FROM NONCONVENTIONAL NATU-RAL RAW MATERIALS

Obtaining and studying the functional properties and determining the subsequent purpose in the practical use of pectin substances requires a thorough study of physical and chemical characteristics of the polysaccharide.&#x0D; By using the acidic hydrolysis method, pectic polysaccharides were isolated from nonconventional raw materials of natural origins - basidial fungus mushrooms Fomes fomentarius, Ganoderma lucidum, Inonotus hispidus, Polýporus squamosus. The polysaccharides isolated were characterized: such as content of free and etherifying carboxyl groups, total -СООН groups, -ОСН3 groups, degree of etherification and by data of the IR-spectroscopy.&#x0D; The pectic polysaccharides isolated in identical conditions from the basidial mushrooms were powders with colors from light yellow to is light-brown by the appearance, possess sub-acidic taste, have no extraneous smack and a smell. The pectin from Inonotus hispidus was much lighter than other pectins (Fomes fomentarius, Ganoderma lucidum, Polýporus squamosus). The pectin’s isolated were similar to the apple pectin by the organoleptic properties. They can classified as averagely etherified pectins regarding the degree etherification. Etherification degree of the studied pectins was in the range of 50.00–66.67%. The methoxyl groups were ranged between 8.47–11.43%. Content of free carboxylic groups in the range of 2.25–5.40%.