Low Methoxy Pectin Research Articles

Acidic dimethyl sulfoxide: A solvent system for the fast dissolution of pectin derivatives suitable for subsequent modification

This study investigates the use of dimethyl sulfoxide (DMSO) as a solvent for the dissolution and subsequent chemical modification of various pectin derivatives. DMSO was found to effectively dissolve low-methoxy pectin, high-methoxy pectin, polygalacturonic acid hydrazide, pectin amide, and polygalacturonic hydroxamic acid when the negative charges on the polysaccharide backbone were neutralized with organic acids. The dissolution process was further enhanced by increasing the temperature, although higher temperatures also promoted chain cleavage. The dissolved pectin derivatives were successfully modified through transesterification and Schiff base formation, demonstrating the potential of acidic DMSO as a non-toxic and cost-effective solvent system for homogeneous pectin chemistry. The study opens new possibilities for the functionalization of pectin in various industrial and biomedical applications.

Anti-inflammatory effects of low-methoxy pectin - a pilot controlled dietary intervention study

Anti-inflammatory effects of low-methoxy pectin - a pilot controlled dietary intervention study

Supplementation with Citrus Low-Methoxy Pectin Reduces Levels of Inflammation and Anxiety in Healthy Volunteers: A Pilot Controlled Dietary Intervention Study.

Background/Objective: Although low-methoxy (LM) pectin (polysaccharides extracted from citrus peels) can reduce inflammation by binding to and inhibiting the TLR-2 pathway in animal models and in vitro studies, the anti-inflammatory effects of LM pectin in humans and mood have not been explored to date. The purpose of this study is to assess the role of dietary supplementation with LM pectin in healthy volunteers on inflammatory markers and on mood, specifically anxiety and depression. Methods: We carried out a 4-week dietary intervention with LM citrus pectin on healthy volunteers (N = 14, age 40 ± 16 y, BMI 24.7 ± 3.0 kg/m2, sex F 57%) comparing the effects of daily supplementation with 20 g of LM citrus pectin versus 10 g of maltodextrin as the control (N = 15 age 43.2 ± 11 y, BMI 25.18 ± 2.0 kg/m2, sex F 66%). The effects on mood and inflammation were also tested with LM pectin at 5 g, 10 g and 15 g (2 weeks each) in an independent cohort of n = 15 healthy volunteers (age 36 ± 21 y, BMI 23.5 ± 2.4 kg/m2, sex F 80%). We assessed serum levels of TNF-alpha (downstream from TLR-2 activation), IL-1 beta, IL-6, IL-10, INF-gamma, CRP, zonulin and TLR-2 concentration which were measured using ELISA in blood samples collected at both the baseline and follow-up visits. Validated measures of anxiety and depression were collected at baseline and follow-up. Results: Supplementation with 20 g of LM pectin resulted in decreases in the pro-inflammatory markers TNF-alpha, IL-1 beta, IL-6 and INF-gamma (all p < 0.05) and an increase in anti-inflammatory marker IL-10 (p = 0.01) at the end of the 4 weeks. No such effects were observed in the control group. In addition, a significant drop in anxiety scores (from 8.38 to 4.46, p < 0.006) was found with the 20 g/day intervention but not in the control arm. In the dose-response study, anti-inflammatory effects were seen only at 15 g for TNFα (p < 0.003) and a suggestive increase in IL-10 (p = 0.08), alongside a drop in TLR-2 (p < 0.027). No significant anti-inflammatory effects were observed at 5 g and 10 g doses of LM pectin supplementation. Significant dose-dependent drops in both anxiety and depression scores were found with 10 g (p < 0.001) and 15 g per day (p < 0.0002). Conclusions: The current study identifies anxiety-reducing and anti-inflammatory effects of supplementation with 15 g/day LM pectin in healthy humans. Further research is needed to elucidate the precise mechanism and to validate the efficient dose and minimum duration of supplementation.

Complex coacervation of low methoxy pectin with three types of gelatins for the encapsulation of fish oil

Herein, the complex coacervation of low methoxy pectin (LMP) with three types of gelatins was explored to encapsulate fish oil. The fish oil@gelatin-LMP complex coacervates with good precipitation separation could be obtained at low gelatin concentrations (Fish gelatin, FG: 10–80 mg/mL; porcine skin gelatin, PSG: 10–40 mg/mL; bovine skin gelatin, BSG: 10–80 mg/mL), high gelatin: fish oil mass ratios (4:1–1:1), appropriate gelatin: LMP mass ratios (3:1–12:1 for FG and PSG, 6:1 for BSG), and appropriate pH (FG: 4.90–5.50; PSG: 4.80–5.40; BSG: 4.10–4.50). FG induced similar loading ability, lower encapsulation ability, and comparable peroxide values to the mammalian gelatins. FG induced higher or similar free fatty acid released percentages to mammalian gelatins in the in vitro gastrointestinal model at low gelatin concentrations (10–40 mg/mL). These results provided useful information to understand the protein-polysaccharide complex coacervation to encapsulate oil-based bioactive substances.

Structural characteristics of cell wall pectic polysaccharides from wampee and their decreased binding with pectinase by wampee polyphenol

To investigate the structural characteristics of cell wall pectic polysaccharides from wampee, water soluble pectin (WSP), chelator-soluble pectin (CSP) and sodium carbonate-soluble pectin (SSP) were purified. And the inhibitory effects of wampee polyphenol (WPP) on pectinase when these cell wall pectic polysaccharides were used as substrates were also explored. Purified WSP (namely PWSP) had the lowest molecular weight (8.47 × 105 Da) and the highest GalA content (33.43%). While purified CSP (called PCSP) and SSP contained more abundant rhamnogalacturonan I side chains. All of them were low-methoxy pectin (DE < 50%). Enzyme activity and kinetics analysis showed that the inhibition of pectinase by wampee polyphenol was reversible and mixed type. When SSP was used as the substrate, WPP had the strongest inhibition (IC50 = 1.96 ± 0.06 mg/mL) on pectinase. Fluorescence quenching results indicated that WPP inhibited enzyme activity by interacting with substrates and enzymes. Therefore, WPP has the application potential in controlling softening of fruits and vegetables.

Feasibility study on the application of pectin as pollen adsorbent to prevent pollinosis

In this study, to investigate the feasibility of applying pectin as an adsorbent to prevent pollinosis, we focused on the two types, low- and high‑methoxy pectin, and investigated its properties for application in nasal mucosa-protective preparations. A film adhesion test was performed, and the number of fluorescent microspheres (FMs) adsorbed to the pectin layer was prepared using a hydrophilic polyvinylidene fluoride filter, and mucin was quantified by fluorescence. High‑methoxy pectin (HMP) caught more FMs than low‑methoxy pectin (LMP)(p < 0.05). The quartz crystal microbalance with dissipation monitoring revealed that HMP adhered more to mucin than LMP. The concentration of HMP did not affect adhesiveness. Furthermore, from evaluating the adsorbency of FMs on pectin and mucin, HMP shows higher adsorbency than LMP (p < 0.05). From these results, it could be concluded that pectin with an HMP had stronger interactions with mucin than LMP and could be applied to the nasal formulation to prevent pollinosis.

ZINC PECTINATE-SESBANIA GUM-MEDIATED INTERPENETRATING POLYMER NETWORK-BASED MICROBEADS AS A CANDIDATE FOR FLOATING DRUG DELIVERY OF ESOMEPRAZOLE

This study aimed to develop esomeprazole-loaded zinc-pectinate-Sesbania gum floating microbeads, optionally supplemented with calcium silicate, as a gastro-retentive drug delivery system. The microbeads were produced using the ionic gelation method, with zinc acetate as the crosslinking agent, and were characterized through in vitro studies. The findings revealed that all formulations exhibited high drug encapsulation efficiency and sustained drug release profiles. Polymer ratios, calcium silicate incorporation, and the choice of low-density oils significantly influenced drug encapsulation efficiency and release kinetics. Notably, the B:6 batch, formulated with Sesbania gum and low methoxy pectin, demonstrated outstanding performance, releasing 95.89 ± 1.66% of the drug within 7 h, with a floating lag time of 1.18 ± 0.07 min, indicating promising in vitro gastro-retention capabilities. Analysis of P-XRD, FT-IR, SEM, and DSC data highlighted changes in crystallinity, drug–excipient compatibility, surface morphology, and thermal behavior of esomeprazole and esomeprazole-loaded microbeads. In conclusion, these floating microbeads represent a potential gastro-retentive drug delivery system, offering enhanced buoyancy and prolonged drug release, with potential therapeutic advantages for peptic ulcer management.

Fabrication and characterization of porous pectin-based aerogels for drug delivery

Aerogels are renowned for their exceptional characteristics such as high porosity and ultra-low density. Among these, pectin aerogels, offering biodegradability, low toxicity, and versatility, are prominent candidates for innovative biomedical materials. This study focused on synthesizing pectin-based aerogels as carriers for ibuprofen and diclofenac sodium. Hydrogels were formed by combining a low methoxy pectin with calcium chloride solution, followed by dehydration and drying using either supercritical carbon dioxide (scCO2) or freeze–drying. Comparative analysis showed scCO2-dried aerogels exhibited slightly less shrinkage (0.27 %) than freeze–dried counterparts. Both types showed high porosity and mesoporous characteristics. However, scCO2-dried aerogels demonstrated higher specific surface area, pore volume, and smaller pore diameter. FTIR spectra indicated no interaction between the drugs and pectin-based aerogels. The loading of ibuprofen in scCO2-dried, pectin-based aerogels at 90, 95, and 100 bar were 60.0 %, 59.9 %, and 52.1 %, respectively, and the solution loading of diclofenac sodium was 38.37 %. At 90, 95, and 100 bar, ibuprofen-loaded pectin-based aerogels were released at 90.0 %, 84.0 %, and 75.5 %, respectively. The release of diclofenac sodium-loaded, pectin-based aerogels was at 88.4 %. The Korsmeyer–Peppas model was fitted for both ibuprofen and diclofenac sodium, indicating the release is mainly driven by diffusion.

Gelation behavior between Nicandra physalodes (Linn.) Gaertn. pectin and Ca2+ is governed by degree and pattern of methylesterification

Nicandra physalodes (Linn.) Gaertn. Pectin (NPGP) is a new type of natural low methoxy pectin (LMP), however, the relatively poor gelling capacity of NPGP and neutral calcium limits its applicability in the food industry. In this study, we improved the gelling capacity of NPGP, and the impact of the degree and pattern of methyl esterification on NPGP gelation behavior triggered by neutral calcium was investigated. To achieve this goal, NPGP was treated with pectin methyl esterase (PME, 30 °C, pH 4.5) for various time. This modification decreased the degree of methyl esterification (DM) and generated different patterns of methyl ester distribution, quantified as the degree of blockiness (DB). The obtained PME-NPGPs possess the ability to form self-supporting gels in the presence of CaCl2, with the highest gel hardness being 331.98 g. By estimating the DM and quantifying the DB of PME-NPGP, the DB value of PME-NPGP was increased from 17.74% to 31.84% with DM decreasing from 33.09% to 17.37%, indicating a shift toward a more blockwise distribution of nonmethylated GalA in NPGP. Additionally, adsorption isotherms for Ca2+ on de-esterified NPGP were determined, enabling the quantification of its cation binding capacity and interaction energy. Reducing DM and increasing DB of NPGP were found to enhance NPGP's binding capacity to Ca2+. This research provides an important foundation for NPGP food processing, and the obtained PME-NPGP can be promising in the fields of food gel and drug delivery.

Preparation of W/O/W Lactiplantibacillus plantarumL3 microcapsules using modified low methoxy pectin as wall materials and their application in simulated yoghurt fermentation systems

This work aimed to characterise water‐in‐oil‐in‐water (W/O/W) microcapsules loading Lactiplantibacillus plantarum L3 in a simulated fermentation and storage process for yoghurt, providing support for their potential application in complex fermented milk systems. The encapsulating efficiency of microencapsulated L. plantarum L3 with modified pectin was 96.79%, the aerobic plate count was 7.83 log cfu/g after simulated gastrointestinal treatment. The microencapsulated L. plantarum L3 delayed the post‐acidification of MRS medium. The cell‐free supernatant produced during the MRS storage period had a bacteriostatic effect. W/O/W microcapsules showed great prospects for application as a probiotics carrier in dairy products.

Evaluation of 3D printability of blueberry powder gel system under ultrasound pretreatment

To achieve the personalized food of 3D manufacturing of blueberry powder (BP) with high nutritional value, the potato starch (PS) and low methoxy pectin (LMP) were selected as matrix material carrying BP to prepare the gels for 3D printing. The 3D printability of the ultrasound-treated gels was evaluated in terms of flow and forming properties. The results indicated that the addition of PS improved the flowability and support stability of the gels due to the non-covalent bonding interaction between the components of the additives and BP via hydrogen bonding. The ultrasound treatment of the gels can cause the cross-linking of PS and LMP to form a uniform and compact structure, which improves the 3D printing fidelity. A Principal Component Analysis-Multiple Linear Regression (PCA-MLR) model is developed to evaluate the 3D printability of BP gels as a function of the flow and thermal properties of the gels, and the texture of the 3D printed food system. The research results may provide a new method for the 3D printing of food powders such as BP.

Modification of pectin with high-pressure processing treatment of fresh orange peel before pectin extraction: Part II. The effects on gelling capacity and emulsifying properties of pectin

The most important functionalities of pectin are gelling and emulsifying properties, which can be tailored by modifying pectin structure through chemical/enzymatic treatments or physical processes. In a companion article (Zhao et al., 2023), the modification of pectin structure with high-pressure processing (HPP) was reported. In this study, the functionalities of the HPP-modified pectins (Hp) were evaluated and compared with commercial low methoxy (LM) and high methoxy (HM) pectins. The calcium sensitivity of Hp was comparable to that of commercial LM pectin, which was remarkably higher than the control pectin extracted from untreated peel and commercial HM pectin. Hp had a dramatically higher gelling capacity for calcium-mediated gelation than the control and commercial HM pectin. The strength and viscoelastic properties of Hp-calcium gels were comparable to that of commercial LM pectin. Meanwhile, most of the Hp also showed a comparable gelling capacity for sugar-acid-mediated gelation to that of the control and commercial HM pectin. Hp also had higher emulsifying stability than the control and commercial pectins. The increased capacity of Hp for calcium-mediated gelation was attributed to the block-wise distribution of non-esterified galacturonic acid (GalA) introduced by the HPP treatment, and the higher emulsifying stability was mainly attributed to the debranching of pectin. The study further confirmed that pectin functionalities were highly correlated with its structural properties. The data reveal the great potential of producing low-cost, high-quality pectins with increased gelling capacity and a broadened scope of applications, by adding a simple HPP pretreatment of fresh source material for pectin extraction.

Sugarcane molasses-induced gelation of low-methoxy pectin

Sugarcane molasses (SCM), a byproduct generated from sucrose manufacturing, has attracted considerable interest due to its high sugar content, polyphenolic compounds, and calcium ions. The objective of this study was to fabricate a type of low methoxy pectin (LMP)-based gel crosslinked by endogenous calcium ions found in SCM. Gel was formed by adding SCM into a 1 wt% LMP solution, which resulted in a Ca2+ concentration of 2–6 mmol/L. Rheological and textural measurements confirmed the formation of SCM-LMP gels. Compared to LMP gels induced by CaCl2, SCM-LMP gels exhibited weak storage modulus and gel strength, probably due to the presence of metal ions and small molecular sugars from SCM, which impede the formation of effective junction zones required for building a calcium-pectin network. The polyphenolic compounds from SCM were encapsulated within the SCM-LMP gel, enhancing its antioxidant capacity. Overall, this research explores the effectiveness of SCM in inducing LMP gelation for the first time. The findings of this study demonstrate a strategy for preparing LMP gels with antioxidant properties.

Effect of localized electrochemical pH and temperature synergistic modification on the structural and antibacterial properties of pectin/polyvinyl alcohol/zinc oxide nanorod films

Two low-methoxy pectins (LMPs) were obtained by local electrochemical pH modification using an H-type double-layer water bath sealed electrochemical cell at the voltage of 180 V for 3 h. The weight-average molecular weight (Mw) of citrus peel pectin (CPP) prepared in the anodic part at room temperature (CPP-A5/RT) and in the cathodic part at 5 °C (CPP-C5/RT) were 346 kDa and 328 kDa, respectively, and the degrees of methylation (DM) were 36.8 % and 11.9 %. Moreover, the second-order kinetic model was most appropriate for the degradation processes, as free radicals were generated in the anodic part and β-elimination occurred in the cathodic part. Subsequently, CPP-A5/RT and CPP-C5/RT were utilized to fabricate food packaging film blending with polyvinyl alcohol (PVA), bcZnO (ZnO coupled with bentonite and colophony) nanorods, and Ca2+ ions by casting method. Then the prepared films were studied for their ability to maintain the freshness of strawberries. The addition of Ca2+ ions and bcZnO nanorods increased the thickness, water contact angle (WCA), and mechanical properties of the composite films, while decreased water vapor permeability (WVP). Therefore, the CPP-based films, supplemented with bcZnO nanorods and crosslinked with Ca2+ ions by “egg-box” model, can serve as an antibacterial food packaging material for food preservation.

Preparation of amphoteric double network hydrogels based on low methoxy pectin: Adsorption kinetics and removal of anionic and cationic dyes

The objective of this research was to devise a functional hydrogel was synthesized using pectin (PE), acrylic acid (AA), dimethyldiallyl ammonium chloride (DC), and polyvinyl alcohol (PVA), designed to adsorb both cationic and anionic dyes concurrently. The low methoxy pectin formed double network hydrogel through chemical and physical crosslinking with AA and PVA respectively. DC is combined into the hydrogel system through copolymerization reaction. Analysis of hydrogel's physicochemical properties was conducted using techniques such as infrared spectroscopy, texture analysis, thermogravimetry, and scanning electron microscopy. Dyes adsorption studies showed that the LP/AA/DC/PVA-2 hydrogel, prepared at the molar ratio of AA to DC of 1:2, exhibited higher adsorption efficiency for methylene blue (MB) and Congo red (CR). Kinetics and isotherms studies indicated that the adsorption behavior conformed to the pseudo-second-order kinetic model and Langmuir isotherm model. By the Langmuir isotherm fitting, the maximum adsorption capacities of MB and CR by LP/AA/DC/PVA-2 were recorded to be 222.65 mg/g and 316.46 mg/g, respectively. The adsorption mechanism is dominated by the hydrogen bonding and electrostatic interactions. Further, the adsorption and desorption experiments demonstrated that LP/AA/DC/PVA-2 hydrogel have excellent reusability.

NADES assisted integrated biorefinery concept for pectin recovery from kinnow (Citrus reticulate) peel and strategic conversion of residual biomass to L(+) lactic acid

The present study aims to establish an integrated strategy for valorization of kinnow peel waste. A total of ten natural deep eutectic solvents (NADESs) were exploited for extraction of pectin. The highest yield of pectin enriched material was reported 35.66 % w/dw using choline chloride-Maltose based NADES. The extraction process parameters and chemical composition of NADES influenced the yield and different associated physico-chemical attributes of the pectin enriched material. All the recovered pectin enriched materials found to be composed of low methoxy pectin (degree of methylation: 18.41–40.26 %) and galacturonic acid (GalA) content was in range of 67.56–78.22 %. The Principal Component Analysis (PCA) was used to categorise isolated pectin enriched materials based on similarities and differences. The liquid fraction upon pectin extraction presented a considerable amount of fermentable sugar which was further utilized for lactic acid production by microbial intervention. The microbial strain Lactobacillus amylophilus GV6 was exploited for lactic acid fermentation where the highest yield reached 55.59 g/L. A sustainable and straight-forward biorefinery concept was developed for extraction of pectin enriched material and lactic acid production from kinnow peel waste with potential application in food and biotechnological sectors.

Anti-diabetic effect of modified ‘Guanximiyou’ pummelo peel pectin on type 2 diabetic mice via gut microbiota

This study aimed to investigate the mechanisms of nature and modified ‘Guanximiyou’ pummelo peel pectin (GGP and MGGP) in alleviating T2DM through in vitro and in vivo. After modification, pectin was transformed from high methoxy pectin (HMP) to low methoxy pectin (LMP), and the content of galacturonic acid was increased. These made MGGP have stronger antioxidant capacity and better inhibition effect on corn starch digestion in vitro. In vivo experiments have shown that both GGP and MGGP inhibited the development of diabetes after 4 weeks of ingestion. However, MGGP can more effectively reduce blood glucose and regulate lipid metabolism, and has significant antioxidant capacity and the ability to promote SCFAs secretion. In addition, 16S rRNA analysis showed that MGGP changed the composition of intestinal microbiota in diabetic mice, decreased the abundance of Proteobacteria, and increased the relative abundance of Akkermansia, Lactobacillus, Oscillospirales and Ruminococcaceae. The phenotypes of the gut microbiome also changed accordingly, indicating that MGGP can inhibit the growth of pathogenic bacteria, alleviate intestinal functional metabolic disorders and reverse the potential risk of related complications. Altogether, our findings demonstrate that MGGP, as a dietary polysaccharide, may inhibit the development of diabetes by reversing the imbalance of gut microbiota.

Characterization of hawthorn pectin gained via different ethanol concentrations.

Pectin is identified as an effective delivery material due to its excellent gel-forming ability, low immunogenic properties, biocompatibility, and biodegradability. These excellent properties depend on the preparation method of pectin. In the study, four pectin fractions (named: CAHP30, CAHP40, CAHP50, and CAHP60, respectively) were obtained by different ethanol precipitations (30%, 40%, 50%, and 60%). Physicochemical properties, antioxidant activity, and emulsifying ability of HP were investigated and analyzed. Results showed that the surface structure of pectin was changed by ethanol fractional precipitation, and four fractions were low methoxy pectin. They had different monosaccharide compositions, but all rich in GalA. The Mw/Mn of CAHP30, CAHP40, CAHP50, and CAHP60 were 3.29, 2.57, 2.66, and 2.77, respectively. CAHP30 and CAHP60 had excellent emulsifying ability; moreover, CAHP60 was endowed with additional lipid antioxidant capacity and had the best thermal stability. E-CAHP40 exhibited a property between the entangled network structure. Overall, pectin with specific properties could be obtained by different ethanol concentrations.

Pectin from plantain peels: Green recovery for transformation into reinforced packaging films

Plantain peels as agro-waste are generated in the millions of tons per year with no profitable management strategies. On the other hand, the excessive use of plastic packaging threatens the environment and human health. This research aimed to address both problems via a green approach. High-quality pectin was recovered from plantain peels via an enzyme-assisted and ethanol-recycling process. The yield and galacturonic acid (GalA) content of the recovered low methoxy pectin was 12.43% and 25.0%, respectively, when cellulase was added at 50 U per 5 g peel powder, with a significantly higher recovery rate and purity than the pectin products extracted with no cellulase (P ≤ 0.05). The recovered pectin was further integrated and reinforced with beeswax solid-lipid nanoparticles (BSLNs) to fabricate films as a potential alternative packaging material to single-use plastics. The reinforced pectin films showed improved light barrier, water resistance, mechanical, conformational, and morphological properties. This study presents a sustainable strategy to transform plantain peels into pectin products and pectin-based packaging films with broad applications.

Physicochemical Properties of Egg-Box-Mediated Hydrogels with Transiently Decreased pH Employing Carbonated Water.

Anionic polysaccharides, including low-methoxy (LM) pectin, are extensively used in biomaterial applications owing to their safety, biocompatibility, and feasibility in constructing supramolecular assemblies by forming egg-box structures with divalent cations. Mixing an LM pectin solution with CaCO3 spontaneously forms a hydrogel. The gelation behavior can be controlled by adding an acidic compound to change the solubility of CaCO3. CO2 is used as the acidic agent and can be easily removed after gelation, thereby reducing the acidity of the final hydrogel. However, CO2 addition has been controlled under varied thermodynamical conditions; therefore, specific CO2 effects on gelation are not necessarily visualized. To evaluate the CO2 impact on the final hydrogel, which would be extended to control hydrogel properties further, we utilized carbonated water to supply CO2 into the gelation mixture without changing its thermodynamic conditions. The addition of the carbonated water accelerated gelation and significantly increased the mechanical strength, promoting cross-linking. However, the CO2 volatilized into the atmosphere, and the final hydrogel became more alkaline than that without the carbonated water, probably because a considerable amount of the carboxy group was consumed for cross-linking. Moreover, when aerogels were prepared from the hydrogels with carbonated water, they exhibited highly ordered networks of elongated porosity in scanning electron microscopy, proposing an intrinsic structural change by CO2 in the carbonated water. We also controlled the pH and strength of the final hydrogels by changing the CO2 amounts in the carbonated water added, thereby validating the significant effect of CO2 on hydrogel properties and the feasibility of using carbonated water.