Pectic Polysaccharides Research Articles

Pectin and homogalacturonan with small molecular mass modulate microbial community and generate high SCFAs via in vitro gut fermentation

The intestinal fermentability of pectic polysaccharides is largely determined by its molecular size. In this study, fermentation properties of enzymatic-modified apple pectin (AP) and homogalacturonans (HG) with high, medium and low molecular weight (Mw) were evaluated by in vitro fermentation model, and their structural changes were also investigated. Results showed that Mw, monosaccharide contents and molecular linearity of the AP hydrolysates were reduced after microbial degradation. On the other hand, culture media supplemented with low-Mw AP (60,300 g/mol) and low-Mw HG (861 g/mol) exhibited lower pH (5.1 and 5.7, respectively) and produced higher total short-chain fatty acid contents (SCFA, 230.40 mmol/L and 187.19 mmol/L, respectively). However, reduced trends in abundance of the pectinolytic microorganisms Faecalibacterium and Eubacterium were showed as Mw of the HG decreased, whereas growth of the SCFA-producer genera Bifidobaacterium, Megasphaera and Allisonella were improved. This work confirmed that low-Mw pectin and homogalacturonan generated more beneficial metabolites, developing structure-microbiota-gut health relationship.

Xylan Structure and Dynamics in Native Brachypodium Grass Cell Walls Investigated by Solid-State NMR Spectroscopy.

The polysaccharide composition and dynamics of the intact stem and leaf cell walls of the model grass Brachypodium distachyon are investigated to understand how developmental stage affects the polysaccharide structure of grass cell walls. 13C enrichment of the entire plant allowed detailed analysis of the xylan structure, side-chain functionalization, dynamics, and interaction with cellulose using magic-angle-spinning solid-state NMR spectroscopy. Quantitative one-dimensional 13C NMR spectra and two-dimensional 13C–13C correlation spectra indicate that stem and leaf cell walls contain less pectic polysaccharides compared to previously studied seedling primary cell walls. Between the stem and the leaf, the secondary cell wall-rich stem contains more xylan and more cellulose compared to the leaf. Moreover, the xylan chains are about twofold more acetylated and about 60% more ferulated in the stem. These highly acetylated and ferulated xylan chains adopt a twofold conformation more prevalently and interact more extensively with cellulose. These results support the notion that acetylated xylan is found more in the twofold screw conformation, which preferentially binds cellulose. This in turn promotes cellulose–lignin interactions that are essential for the formation of the secondary cell wall.

Structural Characterization of Pectic Polysaccharides in the Cell Wall of Stevens Variety Cranberry Using Highly Specific Pectin-Hydrolyzing Enzymes.

The potential of poly- and oligosaccharides as functional ingredients depends on the type and glycosidic linkages of their monosaccharide residues, which determine their techno-functional properties, their digestibility and their fermentability. To isolate the pectic polysaccharides of cranberry, alcohol insoluble solids were first obtained from pomace. A sequential extraction with hot phosphate buffer, chelating agents (CH), diluted (DA) and concentrated sodium hydroxide was then carried out. Pectic polysaccharides present in CH and DA extracts were purified by anion exchange and gel filtration chromatography, then sequentially exposed to commercially available pectin-degrading enzymes (endo-polygalacturonase, pectin lyase and endo-arabinanase/endo-galactanase/both). The composition and linkages of the generated fragments revealed important characteristic features, including the presence of homogalacturonan with varied methyl esterification extent, branched type I arabinogalactan and pectic galactan. The presence of arabinan with galactose branches was suggested upon the analysis of the fragments by LC-MS.

Structural characterization and mechanisms of macrophage immunomodulatory activity of a pectic polysaccharide from Cucurbita moschata Duch.

A pectic polysaccharide (named CMDP-4b) with a molecular weight of 31.97 kDa was extracted from Cucurbita moschata Duch and purified by column chromatography. On the basis of methylation, Fourier-transform infrared, monosaccharide composition, and one- and two-dimensional nuclear magnetic resonance spectroscopy analyses, the structure of CMDP-4b was determined to be composed of an α-1,4-linked homogalacturonan backbone, which was slightly acetylated and highly methyl-esterified, and branched at the O-3 position of the →4)-α-D-GalpA-6-OMe-(1→. Immunomodulatory assays showed that CMDP-4b not only induced the secretion of nitrous oxide and cytokines (i.e. IL-1β, TNF-α, and IL-6) but also promoted pinocytic and phagocytic activities of macrophages, suggesting that CMDP-4b possessed immunomodulatory activity. Moreover, toll-like receptor 4 and complement receptor 3 may play a critical role in CMDP-4b-induced macrophage activation through the NF-κB and the MAPKs signaling pathways. Our study provides the molecular basis for the potential use of CMDP-4b as a natural immunostimulant.

Structural characteristics of three pectins isolated from white kidney bean

Three water-soluble pectic polysaccharides (WKBP-P2, P3 and P4) were isolated from white kidney bean by ion exchange combined with size-exclusion methods. The structural features were characterized by GC–MS, NMR spectroscopy and HPSEC-MALLS-RI. It was found that three pectic polysaccharides were the major water-extracted polysaccharides in white kidney bean. All the WKBP-P2, P3 and P4 were probably composed of various structural regions including homogalacturonan (HG), xylogalacturonan (XGA), rhamnogalacturonan I (RG-I) regions in backbone, and arabinan region mainly as side chain. However, these pectic polysaccharides were significantly different in molar ratios of these structural regions and molecular size. WKBP-P2 was HG-predominant pectin (partially methyl-esterified) with weight-average molecular weight (Mw) of 1.2 × 104 g/mol, and contained minor RG-I, arabinan and probable XGA regions. WKBP-P3 (Mw of 4.0 × 104 g/mol) primarily embraced XGA, HG, arabinan regions and minor RG-I region. WKBP-4 with highest Mw (4.5 × 105 g/mol) had the most arabinan region (51.3%), which was probably the side chain linked to the backbone composed of RG-I, HG and slight XGA regions. These findings provided a structural basis for study on polysaccharides from white kidney bean, which was benefit for development of functional food.

Extraction and characterization of cell wall polysaccharides from cranberry (Vaccinium macrocarpon var. Stevens) pomace

Cranberries of Stevens variety, mainly used for juice production, were processed into pomace, from which alcohol insoluble solids (AIS) were obtained. The cell wall polysaccharides were sequentially extracted from AIS, and characterized in terms of monosaccharide profile, sugar linkage and molecular weight distribution. Pectic polysaccharides represented more than 90% of the carbohydrates contained in hot buffer (HA), chelating agents (CH) and diluted alkali (DA) extracts. HA extract contained homogalacturonan with 75% being methyl esterified, and pectic arabinan with traces of pectic galactan, type II arabinogalactan and 1,4-β-glucan. CH extract, recovered with the highest yield (11.0% w/w), was composed mainly of homogalacturonan. DA extract included homogalacturonan with 2% methyl esterification, abundant arabinan and galactans and traces of 1,4-β-glucan. Glucomannan, xylan and xyloglucan represented 66% of the carbohydrates present in the last concentrated alkali extract (CA), the rest being pectic arabinan and galactan. High molecular weight polysaccharides (>102 kDa) were identified in all extracts.

New pectic polysaccharides from Codonopsis pilosula and Codonopsis tangshen: structural characterization and cellular antioxidant activities.

Codonopsis pilosula and Codonopsis tangshen are plants widely used in traditional Chinese medicine. Two pectic polysaccharides from the roots of C. pilosula and C. tangshen named as CPP-1 and CTP-1 were obtained by boiling water extraction and column chromatography. The core structures of both CPP-1 and CTP-1 comprise the long homogalacturonan region (HG) as the backbone and the rhamnogalacturonan I (RG-I) region as the side chains. CPP-1 has methyl esterified galacturonic acid units and a slightly lower molecular weight than CTP-1. Biological testing suggested that CPP-1 and CTP-1 can protect IPEC-J2 cells against the H2 O2 -induced oxidative stress by up-regulating nuclear factor-erythroid 2-related factor 2 and related genes in IPEC-J2 cells. The different antioxidative activities of polysaccharides from different source of C. pilosula may be result of differences in their structures. All of the results indicated that pectic polysaccharides CPP-1 and CTP-1 from different species of C. pilosula roots could be used as a potential natural antioxidant source. These findings will be valuable for further studies and new applications of pectin-containing health products. © 2021 Society of Chemical Industry.

Carboxylic acid-catalyzed hydrolysis of rhamnogalacturonan in subcritical water media

Rhamnogalacturonans are branched pectic polysaccharides found in most plant cell walls and various agro-industrial residues. A commercial rhamnogalacturonan from soybean was selected as a model substrate to investigate the hydrolytic capacity of aqueous carboxylic acids (citric and malic acids) under subcritical water conditions as a green approach to biomass valorization. The hydrolysis was performed in batch mode at different temperatures (125–155 °C) and reaction times (10–120 min) at constant pressure (100 bar). The HPSEC-RID and HILIC-ELSD analyses showed that aqueous carboxylic acids at 125 °C/100 bar favored cleavage of neutral sugar residues from side chains of rhamnogalacturonan. At 135 °C/100 bar/60 min, scission of rhamnogalacturonan backbone was evident where fractions of 4.7 kDa, 2.1 kDa, and <1.4 kDa were prevalent. Fractions with ≤2.1 kDa were comprised of 2–9 DP (degree of polymerization) oligogalacturonides and 5–10 DP galacto-oligosaccharides. A multi-step sequential hydrolysis mechanism was proposed for rhamnogalacturonan hydrolysis in subcritical water-carboxylic acid media.

Feruloylation of polysaccharides from cranberry and characterization of their prebiotic properties

Humicola insolens feruloyl esterase was immobilized on chemically modified epoxy-activated supports of different pore sizes. Native and immobilized feruloyl esterases were investigated for their esterification activity on raffinose in surfactantless microemulsions. Pectic polysaccharides, obtained from cranberry pomace using chelating agent (CH) and diluted alkaline (DA) extractions, were then esterified at the optimized conditions. Using CH polysaccharide extract as a substrate, immobilized feruloyl esterase led to higher feruloylation (22.1–26.6%) than the free enzyme (4.2%), and yielded polysaccharides with a higher increase in the total phenolic content. Free and immobilized feruloyl esterases acted similarly in the feruloylation of polysaccharides present in the DA extract, identified as being rich in rhamnogalacturonan I neutral branches. The prebiotic activity score showed that cranberry pectic polysaccharides were better fermented than inulin and generated abundant propionic acid. Increased feruloylation of cranberry polysaccharides had a negative impact on the growth of Lactobacillus brevis and Bifidobacterium longum strains. The total short chain fatty acid concentration showed that the presence of feruloylation affected DA polysaccharides more than CH ones. This showed the importance of controlling the feruloylation extent as a compromise between the prebiotic and the antioxidant properties.

Creating polysaccharide-protein complexes to control aqueous lubrication

An emerging understanding of natural biolubricants such as saliva and synovial fluid reveals that they rely on synergistic interactions between biomacromolecules in aqueous media, wherein one polymeric component promotes adsorption to biological substrates while another facilitates hydration lubrication. We hypothesize that this phenomenon can be achieved by combining the strong adsorption characteristics of proteins with the hydration of polysaccharides. To confirm this hypothesis, hydrated soluble complexes were formed through electrostatic interactions between positively-charged lysozyme molecules and anionic residues on pectic polysaccharides extracted from Plantago ovata seed mucilage. Boundary friction was measured between smooth hydrophobic polydimethylsiloxane (PDMS) surfaces using a ball-and-disk tribometer, while adsorption was assessed using a combination of the quartz-crystal microbalance with dissipation monitoring technique and ellipsometry. The results indicate that complexation between polysaccharides and proteins leads to improved adsorption on hydrophobic PDMS surfaces, which in turn decreases boundary friction in sliding contact. By comparing the adsorption behaviour of the complexes and individual components, we conclude that pectic polymers maintain the film's hydration while lysozyme improves surface adsorption, thereby providing new evidence that physical complexes can be utilised to design bi-functional surface layers. Our findings open up a range of opportunities for application in food and oral healthcare products, particularly in the use of food-compatible ingredients to control aqueous lubrication.

The Secretomes of Aspergillus japonicus and Aspergillus terreus Supplement the Rovabio® Enzyme Cocktail for the Degradation of Soybean Meal for Animal Feed.

One of the challenges of the 21st century will be to feed more than 10 billion people by 2050. In animal feed, one of the promising approaches is to use agriculture by-products such as soybean meal as it represents a rich source of proteins. However, soybean meal proteins are embedded in a complex plant cell wall matrix, mostly composed of pectic polysaccharides, which are recalcitrant to digestion for animals and can cause digestive disorders in poultry breeding. In this study, we explored fungal diversity to find enzymes acting on soybean meal components. An exploration of almost 50 fungal strains enabled the identification of two strains (Aspergillus terreus and Aspergillus japonicus), which improved the solubilization of soybean meal in terms of polysaccharides and proteins. The two Aspergilli strains identified in the frame of this study offer a promising solution to process industrial food coproducts into suitable animal feed solutions.

Macromolecular Model of the Pectic Polysaccharides Isolated from the Bark of Norway Spruce (Picea abies).

The bark of Norway spruce (Picea abies) contains up to 13% pectins that can be extracted by pressurized hot water, which constitute a valuable renewable resource in second-generation lignocellulosic biorefineries. This article proposes, for the first time, structural molecular models for the pectins present in spruce bark. Pectin fractions of tailored molar masses were obtained by fractionation of the pressurized hot water extract of the inner bark using preparative size-exclusion chromatography. The monosaccharide composition, average molar mass distribution, and the glycosidic linkage patterns were analyzed for each fraction. The pectin fraction with high molecular weight (Mw of 59,000 Da) contained a highly branched RG-I domain, which accounted for 80% of the fraction and was mainly substituted with arabinan and arabinogalactan (type I and II) side chains. On the other hand, the fractions with lower molar masses (Mw = 15,000 and 9000 Da) were enriched with linear homogalacturonan domains, and also branched arabinan populations. The integration of the analytical information from the macromolecular size distributions, domain composition, and branch lengths of each pectin fraction, results in a comprehensive understanding of the macromolecular architecture of the pectins extracted from the bark of Norway spruce. This paves the way for the valorization of spruce bark pectic polymers in targeted applications based on their distinct polymeric structures and properties.

High pressure processing accelarated the release of RG-I pectic polysaccharides from citrus peel

High pressure processing (HPP) has become a promising strategy for extracting bioactive constituents. In this study, the impact of HPP treatment at various pH values (2.0, 8.0, and 12.0) on the macromolecular, structural, antioxidant capacity, rheological characteristics and gel properties of citrus pectic polysaccharide was investigated. The results showed that pressure and pH significantly affected the yield and Rhamnogalacturonan I (RG-I) characterizations. The yields of high pressure extraction at pH 12 (28.13 %–33.95 %) were significantly higher than the yields at pH 2 (14.85 %–16.11 %) and pH 8 (8.75 %–9.65 %). The yield of HPP (500 MPa/10 min) assisted alkali extraction is more than 2 times of that of HPP assisted acid extraction. The RG-I structure ratio of HPP-alkali extraction pectic polysaccharide (74.51 %) was significantly higher than that of traditional pectin (41.83 %). The results showed that HPP assisted alkali is a potential pectic polysaccharide extraction technology.

Purification, in-depth structure analysis and antioxidant stress activity of a novel pectin-type polysaccharide from Ziziphus Jujuba cv. Muzaoresidue

Ziziphus Jujuba cv. Muzao has attracted researchers for a long time, while residue of jujuba after extracted by water still contains many bioactivities. This paper presents the first study on in-depth structure analysis and its antioxidant of a pectic polysaccharide (PZJRP) separated and purified from Ziziphus Jujuba cv. Muzao residue through alkali extraction. Results of structural and morphological characterization according to high-performance gel-permeation chromatography, methylation analysis and partial acid hydrolysis etc. showed that PZJRP was composed of rhamnose, arabinose, glucose, galactose and galacturonic acid. Main chain of PZJRP including 1,2,4-linked rhamnose and 1,4-linked galacturonic acid, branches attached to C-4 of rhamnose, which suggested that PZJRP was a pectin polysaccharide belongs to rhamngalacturonan I type (RG-I). Significant antioxidant activity of PZJRP was revealed by protecting RAW264.7 cells against H2O2-induced oxidative stress. These findings demonstrated the potential of PZJRP to be a functional thickener as a novel food additive.

STUDY OF THE SORPTION ABILITY OF NATURAL SORBENTS ISOLATED FROM THE CAMPSIS RADICANS

Currently, more and more chemical additives are used in food products, which leads to the accumulation of harmful substances in the body. Therefore, it is relevant to search for new substances of natural origin with detoxification properties. The aim of the work was to determine the sorption ability of pectin substances and water-soluble polysaccharides isolated from the leaves and flowers of the campsis radicans. By the method of N.K. Kochetkova and M. Sinner isolated polysaccharides from water-borne campsis leaves and flowers: water-soluble polysaccharides, pectin, hemicellulose A and hemicellulose B. The adsorption capacity of pectins and water-soluble polysaccharides was studied on the basis of their complexing properties with respect to lead ions. The determination of their content in the raffinate was carried out by titration with a solution of sodium ethylenediaminetetraacetate disubstituted. To evaluate the nature of the sorbent, the calculated Langmuir and Freindlich equations were used. A study of the sorption ability of polysaccharides isolated from leaves of the campsis radicans showed the presence of a high binding ability of Pb2+ ions in pectin substances was associated with 54.2%, and in water-soluble polysaccharides – 37.5%. Polysaccharides isolated from the flowers of the campsis radicans showed sorption activity in the ratio: pectin substances – 32.6%, water-soluble polysaccharides – 80.1%.&#x0D; The expressed complexing ability of the studied polysaccharides with respect to lead ions was revealed. The ratio of the experimental and calculated data on the values of the adsorption of lead ions showed that the sorption process is largely subordinate to the Langmuir equation. Pectic substances and water-soluble polysaccharides obtained from the leaves and flowers of the campsis radicans can be considered as effective detoxifiers. Further study of the physicochemical properties will make it possible to assess the possibility of their biomedical use.

Development of an Affordable, Sustainable and Efficacious Plant-Based Immunomodulatory Food Ingredient Based on Bell Pepper or Carrot RG-I Pectic Polysaccharides.

The prevalence of acute respiratory infections and their impact on quality of life underlies the need for efficacious solutions that are safe, sustainable and economically viable. Polysaccharides in several (traditional) plant extracts have been shown to be immunostimulatory, and some studies suggest beneficial effects against respiratory infections. The aim of this study was to (i) identify the active polysaccharide constituents from affordable and renewable crops (bell pepper and carrot) using activity-guided fractionation, (ii) evaluate in vitro effects on innate immune responses (phagocytosis and cytokine secretion), microbiota modulation and production of short chain fatty acids, followed by (iii) the evaluation of effects of a bell pepper extract enriched for the active component in a human proof of concept study. We identified rhamnogalacturonan-I (RG-I) as the nutricophore responsible for the immunostimulatory activity with substantial structural and functional equivalence between bell pepper (bp) and carrot (c). The in vitro studies showed that bpRG-I and cRG-I comprise similar immune- and microbiota modulatory potential and the human study demonstrated that bpRG-I was well tolerated and enhanced innate immune responsiveness in vivo. This is an important step towards testing the efficacy of RG-I from bpRG-I or cRG-I in an infection trial in humans.

Effects of a High-Molecular-Weight Polysaccharides Isolated from Korean Persimmon on the Antioxidant, Anti-Inflammatory, and Antiwrinkle Activity

Persimmon (Diospyros kaki), a familiar and widespread fruit worldwide, is known to exhibit several physiological effects because of the presence of pharmacologically active compounds called phytochemicals. However, its high-molecular-weight compounds, particularly polysaccharides, have not been extensively studied. In this study, D. kaki extract (DK) was fractionated into low- and high-molecular-weight fractions (DK-L and DK-H, respectively) through ethanol fractionation, and their effects on antioxidant, anti-inflammatory, and antiwrinkle activities were investigated by an in vitro system. DK-H contained significantly higher contents of neutral sugar, uronic acid, and polyphenols compared to DK and DK-L. Furthermore, DK-H exhibited significantly improved pharmacological activities, such as antioxidant, anti-inflammatory, and antiwrinkle properties, compared to those of DK and DK-L, demonstrating that DK-H may play an important role in mediating the beneficial effects of persimmon. Sugar composition analysis and molecular characterization indicated that DK-H consisted of a galacturonic acid (GalA)-rich polysaccharide with a molecular weight of >345 kDa that mainly comprised GalA and small amounts of neutral sugar and polyphenol residues. These results suggest that the bioactive fraction DK-H is likely to be a GalA-rich pectic polysaccharide containing a small number of polyphenol residues, which may be a novel candidate in the pharmaceutical and cosmeceutical industries.

Pectic polysaccharides from Radix Sophorae Tonkinensis exhibit significant antioxidant effects

Two pectic polysaccharides (WRSP-A2b and WRSP-A3a) have been obtained from Radix Sophorae Tonkinensis and comparatively investigated in terms of their physical properties and antioxidant activities. Monosaccharide composition, FT-IR, NMR and enzymatic analyses indicate that both WRSP-A2b (13.6 kDa) and WRSP-A3a (44.6 kDa) consist of homogalacturonan (HG), rhamnogalacturonan I (RG-I) and rhamnogalacturonan II (RG-II) domains, with mass ratios of 0.9:1.8:1 and 2.3:2.9:1, respectively. The RG-I domains were further purified and characterized. Results show that WRSP-A2b contains a highly branched RG-I domain, primarily substituted with α-(1→5)-linked arabinans, whereas WRSP-A3a contains a small branched RG-I domain mainly composed of β-(1→4)-linked galactan side chains. WRSP-A3a exhibits stronger antioxidant activity in scavenging different radicals than WRSP-A2b, a finding that may be due to its higher content of GalA residues and HG domains. Our results provide useful information for screening natural polysaccharide-based antioxidants from Radix Sophorae Tonkinensis.

Extrusion Processing of Pure Chokeberry (Aronia melanocarpa) Pomace: Impact on Dietary Fiber Profile and Bioactive Compounds.

The partial substitution of starch with dietary fiber (DF) in extruded ready-to-eat texturized (RTE) cereals has been suggested as a strategy to reduce the high glycemic index of these food products. Here, we study the impact of extrusion processing on pure chokeberry (Aronia melanocarpa) pomace powder (CPP) rich in DF and polyphenols (PP) focusing on the content and profile of the DF fractions, stability of PP, and techno-functional properties of the extrudates. Using a co-rotating twin-screw extruder, different screw speeds were applied to CPP with different water contents (cw), which resulted in specific mechanical energies (SME) in the range of 145–222 Whkg−1 and material temperatures (TM) in the range of 123–155 °C. High molecular weight soluble DF contents slightly increase with increasing thermomechanical stress up to 16.1 ± 0.8 g/100 g dm as compared to CPP (11.5 ± 1.2 g/100 g dm), but total DF (TDF) contents (58.6 ± 0.8 g/100 g dm) did not change. DF structural analysis revealed extrusion-based changes in the portions of pectic polysaccharides (type I rhamnogalacturonan) in the soluble and insoluble DF fractions. Contents of thermolabile anthocyanins decrease linearly with SME and temperature from 1.80 ± 0.09 g/100 g dm in CPP to 0.24 ± 0.06 g/100 g dm (222 Whkg−1, 155 °C), but phenolic acids and flavonoids appear to be largely unaffected. Resulting techno-functional (water absorption and water solubility) and physical properties related to the sensory characteristics (expansion, hardness, and color) of pure CPP extrudates support the expectation that granulated CPP extrudates may be a suitable food ingredient rich in DF and PP.

Structural conversion of pectin fractions during heat processing in relation to the ability of inhibiting lipid digestion: A case study of hawthorn pectin

This study used hawthorn as object to investigate the relation of structural conversion of pectin fractions during heat processing to the ability of inhibiting lipid digestion. Pectin fractions including water-soluble pectin (WSP), chelator-soluble pectin (CSP), and Na2CO3-soluble pectin (NSP) were isolated from hawthorn tissue after heat processing with different time, as well as the dissolved pectin (DSP) in the heating aqueous phase. The structural features of pectin fractions were characterized by degree of methoxylation, neutral sugar composition, and molecular weight (MW) distribution. After 30-min heat processing, the amount of WSP increased from 78 to 111 mg/g dry basis, while those of CSP and NSP decreased, meanwhile certain amount of DSP (68 mg/g dry basis) was generated. During heat processing, a dynamic alteration of pectin fractions involving solubilization and depolymerization occurred. The solubilization mainly happened in CSP and NSP, inducing a shift from water-insoluble pectin to WSP. The depolymerization occurred in homogalacturonan region of WSP, resulting in a formation of DSP. With the increasing heat time, a more pronounced depolymerization appeared in DSP, which resulted in forming a large amount of pectic polysaccharide fragments with small MW. The WSP showed a good rheological behavior and an ability to inhibit lipid digestion, which was higher than those of DSP. The inhibition rate of WSP (0.1% (w/w)) on lipid digestion decreased from 48.5% to 11.2% after 30-min heat processing. The results can provide novel knowledge to better understand the relation between structure and function of pectin in heat processing.