Degree Of Methoxylation Research Articles

Rheological surface properties of commercial citrus pectins at different pH and concentration

The interfacial activity of commercial low-methoxy (LM) and high-methoxy (HM) pectins from citrus peel was investigated at air-water interfaces by focusing on the role of their molecular weight (MW) and degree of methoxylation (DM). A pendant drop tensiometer was used to carry out transient interfacial tension measurements and small amplitude oscillations. Different pectin concentrations (ranging between 0.00001 g/100 g and 5 g/100 g) and pH conditions (4 and 6) were used during the tests. It was observed that citrus pectins are characterised by interesting surface properties that could allow potential practical uses. Experimental results evidenced that MW affects the diffusion of molecules towards the interface, whereas other investigated parameters (i.e. surface tension, adsorption rate, dynamic moduli) seem more dependent on DM and a clear dependence on MW was not observed. pH conditions modify intermolecular interactions in the bulk and surface layer, even if their effects are related to the fraction and distribution of carboxylic groups along the chain. As a consequence, a complex dependence on investigated parameters was observed and no clear relationship was obtained. Nevertheless, among tested commercial samples LM pectins exhibited the most interesting properties and this behaviour seems related to the intermolecular interactions occurring among them.

A cold-induced pectin methyl-esterase inhibitor gene contributes negatively to freezing tolerance but positively to salt tolerance in Arabidopsis

Plant pectin methyl-esterase (PME) and PME inhibitor (PMEI) belong to large gene families whose members are proposed to be widely involved in growth, development, and stress responses; however, the biological functions of most PMEs and PMEIs have not been characterized. In this study, we studied the roles of CbPMEI1, a cold-induced pectin methyl-esterase inhibitor (PMEI) gene from Chorispora bungeana, under freezing and salt stress. The putative CbPMEI1 peptide shares highest similarity (83%) with AT5G62360 (PMEI13) of Arabidopsis. Overexpression of either CbPMEI1 or PMEI13 in Arabidopsis decreased tissue PME activity and enhanced the degree of methoxylation of cell wall pectins, indicating that both genes encode functional PMEIs. CbPMEI1 and PMEI13 were induced by cold but repressed by salt stress and abscisic acid, suggesting distinct roles of the genes in freezing and salt stress tolerance. Interestingly, transgenic Arabidopsis plants overexpressing CbPMEI1 or PMEI13 showed decreased freezing tolerance, as indicated by survival and electrolyte leakage assays. On the other hand, the salt tolerance of transgenic plants was increased, showing higher rates of germination, root growth, and survival under salinity conditions as compared with non-transgenic wild-type plants. Although the transgenic plants were freezing-sensitive, they showed longer roots than wild-type plants under cold conditions, suggesting a role of PMEs in balancing the trade-off between freezing tolerance and growth. Thus, our study indicates that CbPMEI1 and PMEI13 are involved in root growth regulation under cold and salt stresses, and suggests that PMEIs may be potential targets for genetic engineering aimed to improve fitness of plants under stress conditions.

Effects of microwave power and irradiation time on pectin extraction from watermelon rinds (Citrullus lanatus) with acetic acid using microwave assisted extraction method

The aims of this research are to study the effect of microwave power (119.7 W, 199.5 W and 279.3 W) and irradiation time (6, 9 and 12 min) on pectin extraction by using Microwave Assisted Extraction (MAE) with acetic acid and to do a preliminary characterization of pectin from watermelon rinds. A randomized factorial design with two factors was used to determine the effect of microwave power and processing time on the yield, equivalent weight, degree of methoxylation (DM), galacturonic acid content (GA) and the degree of esterification (DE) of extracted pectin. The results showed that extracted pectin from watermelon rinds using MAE method have yield ranged from 3.925% to 5.766%, with equivalent weight ranged from 1249.702 to 2007.756. Extracted pectin have a DM value ranged from 3.89% to 10.81%. Galacturonic acid content that meets with IPPA standard resulted from extraction condition of 279.3-watt microwave power for 9 min and 12 min. The degree of esterification (DE) value ranged from 56.86% to 85.76%, and this value exhibited a relatively high methoxyl pectin (>50%). The best pectin properties was obtained at a microwave power of 279.3 watts for 12 min.

Ultrasonic Modified Sweet Potato Pectin Induces Apoptosis like Cell Death in Colon Cancer (HT-29) Cell Line

ABSTRACTBackground: Pectin and especially modified citrus pectin possesses anticancer activity. Hence, the current study investigated anticancer activity of ultrasonic-modified sweet potato pectin (SPP) on HT-29 cells to assess its potential as a cancer therapeutic agent. Method: The effect of ultrasonic treatment on SPP molecular weight, galacturonic acid content, degree of methoxylation, and neutral sugar was investigated. Moreover, the effect of sonicated variant on human HT-29 cell proliferation was assessed by MTT assay, cell cytotoxicity, and apoptosis by Annexin V/PI flow cytometer and caspase-3 activity was studied. Results and discussion: Sonication led up to seven-fold decrease in molecular weight. The degree of methoxylation (DM) decreased more than two-fold. Moreover, the galacturonic acid (GalA) content increased up to 92%, arabinose and galactose content increased. The SSPP inhibited cell proliferation with the IC50 values 0.5 mg/ml and 0.75 mg/ml for 400 W and 200 W SSPP, respectively. Moreover, 14.41 ± 1.64% cell cytotoxicity was elicited by 400 W SSPP and 6.83 ± 0.80% by 200 W SSPP. Both SSPPs induced apoptosis with 400 W SSPP eliciting 19.42% and 42.21% apoptosis at 0.1 and 0.5 mg/ml, while 200 W SSPP induced 13.79% and 39.50% apoptosis at 0.1 and 0.5 mg/ml, respectively. SSPP activity increased with both increased concentration and sonication intensity.

Effects of ultrasound pretreatment on the enzymolysis of pectin: Kinetic study, structural characteristics and anti-cancer activity of the hydrolysates

In this study, the effects of ultrasound pretreatment on the enzymolysis of pectin were investigated. Ultrasound at an intensity of 18.0 W mL−1 for 30 min significantly decreased pectin molecular weight by 50.50%, whereas it increased the degree of hydrolysis (DH) for enzymatic reactions by 20.22%. After ultrasound treatment, the maximum velocity of the enzymatic reaction (Vmax) increased but the Michaelis constant (Km) decreased, indicating an improved enzymolysis efficiency and stronger affinity between pectin and pectinase. Investigations into pectin structures demonstrated that, ultrasound effectively decreased the degree of methoxylation (DM) resulting in more favorable substrates for enzymatic attack; thus, the homogalacturonan (HG) regions of the pretreated pectin were more completely degraded during enzymolysis compared with the control. According to the results of FT-IR and NMR analysis, both ultrasound and pectinase had no effect on pectin primary structures. However, ultrasound pretreatment could induce higher content of galactose in pectin hydrolysates, which contributed to an improved inhibitory activity against HT-29 colon cancer cells as shown by MTT assay.

Methoxyflavones from Marcetia taxifolia as HIV-1 Reverse Transcriptase Inhibitors

Methoxyflavones are flavonoid widely distributed in plants and has been reported as potent antitumor agents and some of them have shown activity against HIV-1. In this work, two methoxyflavones isolated from Marcetia taxifolia were evaluated in vitro and in silico as HIV-1 inhibitors. Pentamethoxyflavone (5,3’-dihydroxy-3,6,7,8,4’-pentamethoxyflavone) (PMF) and Hexamethoxyflavone (5-Hydroxy-3,6,7,8,3’,4’-hexamethoxyflavone) (HMF) showed activity against HIV-1. The EC50 for HMF was 0.05 μM and 0.04 μM for PMF. The methoxyflavones also inhibited HIV-1 reverse transcriptase (RT), with an IC50 of 4.1 μM for HMF and 0.4 μM for PMF. PMF exhibited an IC50 lower than nevirapine (1.4 μM). These results are in agreement with the in silico prediction for the interaction of these flavonoids with RT. Furthermore, the effect of some methoxyflavones with different patterns of methoxylation was evaluated on RT activity in a virtual screening; found that the inhibitory activity was inversely proportional to the degree of methoxylation.

Acoustic cavitation assisted extraction of pectin from waste grapefruit peels: A green two-stage approach and its general mechanism

In the present study, acoustic cavitation assisted extraction (ACAE) which is a green approach was used for two-stage extraction of pectin from waste grapefruit peels regarding the specific two stages and different peel particle sizes. The yields, physicochemical properties and structure prediction of pectin from different peel particle sizes and different stages by two methods were compared. Highest pectin yield of 23.49% was achieved at the peel size of 0.9mm and was slightly higher than the yield of 23.44% at finer particle size. ACAE achieved four times higher yield compared with conventional heating method (CHE) at the second stage. ACAE pectin which had lower molecular weight and degree of methoxylation was richer in rhamnogalacturonan-I (RG-I) region with long side chains compared with CHE pectin from chemical and FT-IR analysis. Based on the results, a potential general mechanism for ACAE of plant cell wall viscous polysaccharides was discussed in terms of the effects of cavitation on the swelling index and morphological study of residue to reveal the “barrier effect” during the process. Furthermore, the energy consumption for ACAE was significantly lower than the conventional method, indicating its promising application in industrial scale.

Orange pulp and peel fibres: pectin-rich by-products from citrus processing for water binding and gelling in foods

Pulp and peels are the main by-products during juice extraction of citrus fruits. Typically, they contain large amounts of cell wall polysaccharides and can be a source of dietary fibres which are rich in pectin. In the past, numerous studies have focussed on hydration properties of fruit derived dietary fibres but very limited information is available on their gelling properties. The aim of the present study was to investigate both water binding and gelling properties of two orange fibre preparations from pulp and peel with a galacturonan content >27% and a degree of methoxylation >65%. The water retention capacity (WRC) of these fibres was significantly increased by mechanical pre-treatment but decreased by high temperatures (80 °C) during soaking. Moreover, intrinsic factors of the soaking solution significantly affected the water binding properties: a raising pH increased the WRC whereas the incorporation of calcium decreased it. Pulp fibre showed superior water binding properties compared to peel fibre. Gelling properties were evaluated by means of oscillation measurements as well as texture analyses and revealed that pulp and peel fibres were able to form sugar-acid gels at low pH < 2.7 and soluble solids loads of 55 and 60%, respectively. Pulp fibre exhibited similar gel points like isolated citrus pectin. Fibre gels were, however, less elastic than citrus pectin gels. Possibly this is a consequence of the swollen fibre matrix which might interfere with the pectin gel network.

Structure formation in sugar containing pectin gels - Influence of gel composition and cooling rate on the gelation of non-amidated and amidated low-methoxylated pectin

Gel structure formation and gel properties of low-methoxyl pectin (LMP) and low-methoxyl amidated pectin (LMAP) with similar degree of methoxylation have been investigated by oscillatory rheological measurements. The gelling process was examined in a sugar-acid environment matching the conditions in jams and jellies. Factors studied included cooling rate, calcium content and pH. Parameters derived from the rheological measurements comprised the gel point, structuring velocity, initial and critical structuring temperature, average structuring developing rate and loss factor (tanδend).The influence of the cooling rate on the gelling process of LMP was moderate and the influence on the final gel properties was significant, tanδend decreased with increasing cooling rate. The calcium content significantly affected the structuring process of LMAP and the final gel properties. At high calcium content, the gelling process started at a higher temperature but the resulting gels were less strong. The pH had a significant but partly opposite effect on the gelation of LMP as well as LMAP. The differences in gelation behavior between LMP and LMAP can be explained by the lower number of available blocks of free carboxyl groups in LMAP as well as by the formation of additional hydrogen bonds through the amide groups.

Physico-chemical and viscoelastic properties of high pressure homogenized lemon peel fiber fraction suspensions obtained after sequential pectin extraction

The viscoelastic properties of high pressure homogenized lemon peel cell wall fiber suspensions, obtained after sequential selective pectin extraction, were investigated in the current study. For comparison, a general pectin extraction was additionally performed on lemon peel under acid thermal conditions. The obtained insoluble residues and solubilized pectin fractions were characterized based on their neutral sugar and galacturonic acid content, degree of methoxylation and molar mass distribution. Subsequently, microstructure and viscoelastic characteristics of the diverse insoluble residue suspensions were investigated by means of microscopic visualization, determination of the particle size distribution and rheological properties after high pressure homogenization.Due to the use of different extraction conditions, the insoluble cell wall residues were found to have diverse pectin characteristics and contents. While homogenization of non- or moderate-depleted cell wall suspensions resulted in small viscoelastic moduli due to the disruption of the stiff microfibrillar cell wall network, extensive pectin removal was found to correlate to large viscoelastic moduli of the cell wall suspension upon high pressure homogenization. It is suggested that an extensive pectin extraction resulted in the creation of interfibrillar voids within the cellulose-hemicellulose network, increasing the cell wall flexibility and hydration of the fibers upon suspension. Due to the increased flexibility of this fiber network, the interfibrillar voids in the pectin depleted cell wall material were proposed to expand with increasing pressure level during high pressure homogenization of the generated cell wall suspensions, thereby increasing its viscoelastic properties.

Using the high temperature resistant pH electrode to auxiliarily study the sugar beet pectin extraction under different extraction conditions

A full two-level factorial experiment design was employed to investigate the effects of temperature (75 and 85 °C), time (2 and 3 h) and initial pH(1.5 and 2.0) on the molecular composition of sugar beet pectin extracted by citric acid. And the high temperature resistant pH electrode was used to monitor the pH variation during pectin extraction. The results showed that the pH of pectin extraction solution was not constant during pectin extraction, and the pH of extraction solution fluctuated more widely at 85 °C than at 75 °C. In the experiment design, the initial pH was the most significant factor on pectin composition such as arabinose, total neutral sugars, and degree of acetylation, while the temperature became the most important factor for yield, galacturonic acid, rhamnose, galactose, and weight-average molar mass. The degree of methoxylation was significantly affected by extraction time. It was observed that the emulsifying properties of the extracted pectin samples were significantly affected by the extraction conditions. All the results revealed that 1.) the pH value of extraction solution is directly related to the yield and the degradation of the extracted pectin during sugar beet pectin extraction, 2.) the extraction temperature could significantly affect the pH fluctuation of extraction liquid, 3.) the most significant effect factor for a given pectin composition is dominated by the pH fluctuation of the extracting liquid and acid stability of this discussional pectin composition, 4.) beet pectin extracted by citric acid is an effective emulsifier.

Effects of pectin structure and crosslinking method on the properties of crosslinked pectin nanofibers

We reported crosslinking of electrospun nanofibers of three representative pectins (high-methoxylated, low-methoxylated, low-methoxylated and amidated pectin) and characterization of the crosslinked nanofibers. One mono-crosslinking strategy and two dual-crosslinking strategies were developed. Mono-crosslinking is achieved using calcium ions (Ca2+) to crosslink carboxylate ions in galacturonic acid residues. Dual-crosslinking is achieved using covalent crosslinking reagents glutaraldehyde (GLU) or adipic acid dihydrazide (ADH) to further crosslink hydroxyl groups or carboxylate ions after Ca2+ crosslinking. Mechanical tests and degradation experiments indicated pectin structure affected mechanical and degradation properties of Ca2+-crosslinked nanofibers remarkably. Subsequent GLU crosslinking improved their mechanical strength moderately but did not inhibit their degradation, while subsequent ADH crosslinking improved their mechanical strength and slowed down their degradation dramatically. Cell studies demonstrated that most crosslinked pectin nanofibers were of no obvious cytotoxicity, and both ADH crosslinking and high degree of methoxylation facilitated cell adhesion and proliferation on pectin nanofiber mats.

Investigation on the influence of pectin structures on the pasting properties of rice starch by multiple regression

This work investigated effects of the galacturonic acid content (GA), degree of methoxylation (DM), degree of amidation (DA) and molecular weight (MW) of pectin on the pasting properties of rice starch (RS). Pectins with varying structures were selected randomly. Different pectins when added to RS showed significant differing (p < 0.05) influences on pasting properties of RS. Multiple regression analysis was adopted to establish equations between structural characteristics of pectin and pasting properties of RS. The obtained equations had a good fit (all R2 ≥ 0.936), and relative errors of pasting properties for prediction group were very close to the coefficient of variation (except breakdown). The contribution of the specific pectin structural characteristic on the change of the pasting properties of RS was also evaluated. DM was greatly correlated with peak and trough viscosity. Breakdown was strongly affected by DA and GA. Two primary factors that affected setback were the MW and GA. Furthermore, peak time was mainly influenced by DA.

Ultrasonic degradation of sweet potato pectin and its antioxidant activity

The effect of ultrasound factors (time, power, and duty cycle) on sweet potato pectin molecular weight, neutral sugar composition, pectin structure, and antioxidant activity was investigated. Sweet potato pectin dispersions (0.0025, 0.005 and 0.01g/mL) in deionized water were sonolyzed for 5, 10 and 20min to assess effect of sonication time and pectin concentration on sonolysis. For further experiments 0.0025g/mL was sonicated under varying ultrasonic power and duty cycle levels, subsequently the molecular weight, galacturonic acid content, degree of methoxylation and antioxidant activity of sonicated pectin products were investigated. Results showed that ultrasound treatment reduced pectin molecular weight, while polydispersity did not show clear trend which characterized random pectin scission, increasing duty cycle from 20% to 80% resulted in approximately threefold reduction in pectin molecular weight, increased sonication power from 100W to 400W led to significant increase in galacturonic acid content from 72.0±1.2% in native pectin to between 85.0±3.2% and 92.0±2.7%, the degree of methoxylation significantly reduced from 12.0±3.0% to between 5.25% and 6.28%, sonication led to increase in galactose and decrease in rhamnose consistent with debranching of pectin. Moreover, sonication lead to increased antioxidant capacity, both 200W and 400W sonicated pectin having higher ORAC and FRAP values, with highest pectin concentration 4mg/mL in ORAC and 0.8mg/ml in FRAP giving substantially high antioxidant activity than native and 100W treated pectin. The ORAC value of 400W sonicated pectin increased five hold above the native pectin, while it’s FRAP value was almost three fold higher than native pectin. However, ultrasound did not alter pectin primary structure as showed by FTIR and HPAEC results. The results indicated that ultrasound offers effective and green process for pectin transformation and creation of antioxidant potent pectin products.

Effect of low and high methoxyl citrus pectin on the properties of polypyrrole based electroactive hydrogels

Electroactive hydrogels were prepared using commercial citric pectin, either raw (PC) or purified through dialysis (dPC), and chemically synthesized polypyrrole (PPy). 1H NMR analyses showed that PC is a low methoxyl pectin (degree of methoxylation, DM=46%) and dPC is a high methoxyl pectin (DM=77%). The pyrrole polymerization was monitored through UV⿿vis spectroscopy and both samples were observed to be good stabilizers for PPy in aqueous medium. The dispersions were used to prepare the hydrogels h-PC-PPy and h-dPC-PPy. The hydrogel h-dPC-PPy has a higher swelling index (SI⿿25%) at pH 1.2 than the hydrogel h-PC-PPy (SI⿿7%). Contrastingly, at pH 6.8 both hydrogels lost their mechanical integrity. Raman spectroscopy revealed that PPy is more oxidized in h-PC-PPy. Nevertheless, both hydrogels are electroactive and therefore can be considered for applications in which the control of the degree of swelling is desired.

Impact of enzymatic hydrolysis on the interfacial rheology of whey protein/pectin interfacial layers at the oil/water-interface

Aim of the present study was to investigate the complex formation of β-lactoglobulin (β-LG) hydrolysates and different types of pectin at the oil/water-interface by dynamic interfacial pressure and the properties of the complexes by interfacial rheology (dilatation and shear). The degree of hydrolysis (DH) of β-LG was varied (3 and 6%) as well as the degree of methoxylation of the pectins, i.e. two low-(LMP, 32 and 35%) and two high-methoxylated (HMP, 64%) pectins were used. The pectins exhibited different local charge densities, due to enzyme specificity during demethoxylation. All experiments were performed at a constant biopolymer content (0.01 wt%), pH (4.0) and temperature (22 °C). β-LG/pectin interactions clearly delayed interfacial adsorption, which was more pronounced for LMP with a high local charge density. With increasing DH of β-LG, the interfacial adsorption was accelerated, however β-LG/pectin layers exhibited higher dilatational elastic moduli than hydrolysate/pectin layers. In contrast to dilatational rheology, β-LG formed weaker interfacial layers than its hydrolysates during shear time sweeps, despite the presence of pectin. Pectin and hydrolysates exhibited strong viscoelastic interfacial layers partially more than one order of magnitude higher than β-LG. However, during shear amplitude sweeps all interfacial layers were resistant to increasing strain and the films collapsed within the same region. Therefore, targeted structural modifications using enzymes with high specificity enables the production of β-LG hydrolysates and demethoxylated pectins with tailored functionality with respect to their interfacial rheology characteristics.

Degradation kinetics and structural characteristics of pectin under simultaneous sonochemical-enzymatic functions

This study investigated the degradation kinetics and structural properties of pectin with combining ultrasound and pectinase treatment. Ultrasound at an intensity of 4.5WmL−1 and a time of 10min significantly enhanced the enzymatic degradation of pectin weight-average molecular weight (Mw). The degradation kinetics model of pectin followed 1/Mwt−1/Mw0=kt, suggesting the randomness of the degradation process. Synergistic effects of ultrasound and pectinase were observed at 20–60°C and were more effective at lower temperatures. Furthermore, the degree of methoxylation (DM) of sonoenzymolysis pectin significantly decreased whereas the degree of acetylation (DAc) remained unchanged compared to the original and enzymolysis pectin. Simultaneous functions of ultrasound and pectinase caused severe decomposition in pectin homogalacturonan (HG) regions without altering the monosaccharides types, configurations and glycoside linkages of the pectin samples. The complex polymeric structures of pectin transformed into smaller units with simpler branches and shorter chains after sonoenzymolysis reactions.

Development of Crystal Violet encapsulation in pectin - Arabic gum gel microspheres

Six pectins with 35% to 91% methoxylation degree were purified and characterized to encapsulate Crystal Violet (CV). Amidated low methoxylated pectin (ALMP) was selected based on microsphere morphologies, aqueous solubility, viscosity and the effect of calcium concentration. Pectin microspheres were stabilized with Arabic gum (AG) and optimized according to the loading. Microspheres composed of 2.0% ALMP-1.0% AG crosslinked with 450mM calcium(II) were able to encapsulate 217±2μM CV. Optical microscopy of the gels revealed spheroid microspheres with 250±50μm diameter containing homogenous CV distribution. Dried microspheres observed by SEM and epifluorescence showed a highly shrinkable matrix keeping the spheroidal morphology. Low relative viscosity of the ALMP-AG-CV solutions was found compared to ALMP and ALMP-AG. The Young moduli (60–80Pa) of ALMP-AG microspheres by texturometric analysis indicated that the CV could interfere with the gel crosslinking. Raman spectroscopy analysis suggested some interaction of CV nucleophilic center within the matrix. FTIR of the matrix showed largest shifts in the carbonyl and carboxylate groups probably associated to H-bridges. CV stability studies performed on ALMP-AG microspheres, synthetized from polymer solutions with pH values above and below pectin pKa and showed faster CV release rates in presence of ionic strength.

Extraction and characterization of pectic substances in Myrciaria cauliflora (Jaboticaba sabará) fruit

The jaboticaba is a fruit that is native to Brazil, which has antioxidant activity and is known to have levels of bioactive compounds. This fruit is a berry with a lilac-coloured husk and white flesh; sweet and acid, which justifies its high levels of fresh consumption. The aim of this study was to contribute to the study of a new raw material in small agribusinesses. Jaboticaba- Sabara variety- was fractionated into three parts for pectin analysis: the skin, pulp and juice. The pectic substances of the jaboticaba were analysed. The degree of methoxylation was determined by titration and infrared spectroscopy (FTIR). Pectin extracted from the skin had a higher degree of esterification. The macromolecular composition, determined by high pressure steric exclusion chromatography (HPSEC), discriminated the pectins of high molar mass (skin) and low molecular weight (juice and pulp). The pectin from all the fractions presented homogalacturonan segments with a high degree of esterification, and ramnogalacturan side chains composed of galactose and arabinose. The jaboticaba pectins presented a high content of arabinose in the skin, whilst galactose was only found in traces in the juice, showing different proportions of monosaccharides, similar to commercial samples of apple pectin.

Characterization of pectin from grapefruit peel: A comparison of ultrasound-assisted and conventional heating extractions

In the present study, properties of pectin from grapefruit (Citrus paradisi Macf. cv. Changshanhuyou) peel extracted by ultrasound-assisted extraction (UP), were compared with those of pectin extracted by conventional heating extraction (CP). UP exhibited a lower molecular weight (Mw) but more concentrated Mw distribution than CP. Although both UP and CP were high-methoxyl pectin, UP showed significantly lower degree of methoxylation but higher degree of acetylation. Monosaccharide composition analysis showed that the molecular structure of UP possessed more branch chains than CP, but little difference was observed in the chemical structures between UP and CP from FT-IR and NMR spectra analysis. X-ray diffraction (XRD) analysis further confirmed that UP had decreased level of crystallinity than CP. Moreover, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated UP had higher thermal stability. UP exhibited lower apparent viscosity and elasticity than CP, showing that ultrasound affected the rheological properties of pectin. Besides, antioxidant activity and lipase inhibitory capacity of UP significantly enhanced compared with CP.