Viscosity Of Pectin Research Articles

Viscosity of Pectin-[BMIM][PF6] electrolytes and the interplay of ion-ion interactions

Polymer embedded ionic liquid type of composite electrolytes are attracting considerable attention for advanced rechargeable batteries, offering enhanced performance, environmental sustainability, and safety. This study employs classical molecular dynamics simulations to investigate a composite electrolyte comprising pectin and 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) IL. We conduct extensive simulations to calculate the viscosity using the Green-Kubo approach and examine the interplay of ion-ion and ion-polymer interactions through radial distribution functions and free energy analyses. Our simulations revealed that the addition of pectin chains leads to a notable increase in viscosity, which scales exponentially with the loading (x) of pectin as η=6.83ex/11 mPa.s. The interplay of competing interactions between the cation–anion and ion-polymer pairs dictates the structural arrangement of ionic species to favor decreasing trends for ion coordination with potential benefits to efficient ionic conductivity within the polymer-IL electrolyte systems. These findings elucidate the multifaceted dynamics of pectin-IL electrolytes, underlining their suitability as advanced battery electrolyte materials.

The nonlinear mechanics of highly extensible plant epidermal cell walls.

Plant epidermal cell walls maintain the mechanical integrity of plants and restrict organ growth. Mechanical analyses can give insights into wall structure and are inputs for mechanobiology models of plant growth. To better understand the intrinsic mechanics of epidermal cell walls and how they may accommodate large deformations during growth, we analyzed a geometrically simple material, onion epidermal strips consisting of only the outer (periclinal) cell wall, ~7 μm thick. With uniaxial stretching by >40%, the wall showed complex three-phase stress-strain responses while cyclic stretching revealed reversible and irreversible deformations and elastic hysteresis. Stretching at varying strain rates and temperatures indicated the wall behaved more like a network of flexible cellulose fibers capable of sliding than a viscoelastic composite with pectin viscosity. We developed an analytic framework to quantify nonlinear wall mechanics in terms of stiffness, deformation, and energy dissipation, finding that the wall stretches by combined elastic and plastic deformation without compromising its stiffness. We also analyzed mechanical changes in slightly dehydrated walls. Their extension became stiffer and more irreversible, highlighting the influence of water on cellulose stiffness and sliding. This study offers insights into the structure and deformation modes of primary cell walls and presents a framework that is also applicable to tissues and whole organs.

Characterization of partial acid hydrolysates of citrus pectin for their pasting, rheological and thermal properties.

Pectin was subjected to acid hydrolysis with hydrochloric acid for 30 and 60min to prepare partial hydrolysates (PH30 and PH 60). The influence of acid hydrolysis on the physico-chemical and functional properties were assessed for their potential applications in foods. Acid hydrolysis significantly reduced the molecular weight and viscosity of pectin in a time dependent manner. Steady shear properties revealed a shear-thinning behavior for NP and PH 30 while Newtonian behavior was observed for PH 60. Oscillatory measurements revealed a viscoelastic behavior for NP while a viscous liquid like behavior was observed for PH30. DSC measurements also revealed reduced thermal stability of pectin hydrolysates in comparison to native pectin. The results of the present study suggested that pectin hydrolysates with improved solubility can be used in various food products as a source of dietary fiber without modifying the texture and palatability of food products.

Physicochemical properties and biological activities of novel blend films using oxidized pectin/chitosan

Pectin has been widely used in a variety of biomedical applications. In this study, it was modified with sodium periodate as an oxidant and characterized by physicochemical methods Periodate oxidation increased the contents of dialdehyde units and carboxyl groups in pectin, and a decrease in pectin viscosity was measured. The oxidization reaction led to a significant decrease in all values of molecular weight and size (Mn, Mw, [η] and Rh) as determined by size exclusion chromatography (SEC), which allowed the selection of the oxidized pectin to be added to chitosan. Chitosan-based films were characterized by infra-red spectroscopy (FTIR), X-ray diffractometry (XRD), and differential scanning calorimetry (DSC) measurements. Thermal behaviour studies demonstrated that interactions existed between chitosan and oxidized pectin. The haemolysis percentages of films were found to be less than 5%, which indicated their good blood compatibility. Finally, the antibacterial activity was clearly improved. Cross-linking reactions between pectin and chitosan through ionic bonds and amide bonds and between chitosan and oxidized pectin through Schiff base formation were evidenced, which opens the way to extend applications of these polysaccharides; notably, the biocompatibility and biodegradability of these new networks is convenient for pharmaceutical, biomedical or cosmetic applications.

Pectic principles of mango peel from mango processing waste as influenced by microwave energy

Mango var. Totapuri is extensively processed into mango puree by the fruit processing industries. It results in generation of huge quantities of processing waste comprising of mango peel, stone and fibre. Microwave energy levels of 250, 440, 660 and 1000 W with time period ranging from 10 min to 25 min were studied for pectin extraction from mango peel. Microwave extraction affected the yield, methoxyl content, galacturonic acid and viscosity of pectin. Maximum pectin yield could be obtained with a short heating period as compared to the conventional method of extractions reported earlier. Higher methoxyl content and viscosity were observed in the mango peel pectin extracted at 660 and 1000 W for 20 min indicating the better gelling properties of the pectin. Yield of pectin was found to be maximum from the mango peel exposed at microwave energy of 1000 W for 20 min. Methoxyl content, viscosity, galacturonic acid decreased at 25 min of extraction at all microwave energy levels studied. Pectin extracted at the optimum conditions contained galacturonic acid, methoxyl content and viscosity of 57.2 g/100 g, 8.2 g/100 g and 98.2 mPa s respectively. Microwave extraction of mango peel under selected conditions resulted in higher yield of pectin.

Heterologous expression of a Penicillium purpurogenum pectin lyase in Pichia pastoris and its characterization

Lignocellulose is the major component of plant cell walls and it represents a great source of renewable organic matter. One of lignocellulose constituents is pectin. Pectin is composed of two basic structures: a ‘smooth’ region and a ‘hairy’ region. The ‘smooth’ region (homogalacturonan) is a linear polymer of galacturonic acid residues with α-(1→4) linkages, substituted by methyl and acetyl residues. The ‘hairy’ region is more complex, containing xylogalacturonan and rhamnogalacturonans I and II. Among the enzymes which degrade pectin (pectinases) is pectin lyase (E.C. 4.2.2.10). This enzyme acts on highly esterified homogalacturonan, catalysing the cleavage of α-(1→4) glycosidic bonds between methoxylated residues of galacturonic acid by means of β-elimination, with the formation of 4,5-unsaturated products. In this work, the gene and cDNA of a pectin lyase from Penicillium purpurogenum have been sequenced, and the cDNA has been expressed in Pichia pastoris. The gene is 1334 pb long, has three introns and codes for a protein of 376 amino acid residues. The recombinant enzyme was purified to homogeneity and characterized. Pectin lyase has a molecular mass of 45 kDa as determined by SDS-PAGE. It is active on highly esterified pectin, and decreases 40 % the viscosity of pectin with a degree of esterification ≥85 %. The enzyme showed no activity on polygalacturonic acid and pectin from citrus fruit 8 % esterified. The optimum pH and temperature for the recombinant enzyme are 6.0 and 50 °C, respectively, and it is stable up to 50 °C when exposed for 3 h. A purified pectin lyase may be useful in biotechnological applications such as the food industry where the liberation of toxic methanol in pectin degradation should be avoided.

Optimization of the preparation of pectin from Aloe using a Box–Behnken design

The extraction condition of pectin from Aloe vera barbadensis Mill was optimized by a Box–Behnken design. The effect of parameters of extraction water proportion (EWP), extraction pH (EpH), extraction temperature (ETe), extraction time (ETi), alcohol precipitation pH (APpH)and alcohol precipitation temperature (APTe) on the extraction yield of pectin was investigated by a software of Design Export 8.0.5b. The maximum extraction yield was obtained with the EWP of 20:1, EpH of 1.5, ETe of 90°C, ETi of 120min, APpH of 3.0 and APTe of 50°C, which was consistent with the experimental value. We also found out that the pectin content decreased gradually during storage and sucrose concentration had a significant impact on the viscosity of pectin.

Emulsion stabilizing properties of pectins extracted by high hydrostatic pressure, high-speed shearing homogenization and traditional thermal methods: A comparative study

In the previous studies, two novel methods for pectin extraction, using high hydrostatic pressure (HHP) and high-speed shearing homogenization (HSHE), were developed with higher efficiency, less time and energy consumptions than traditional thermal extraction (THE); however, many functional properties of these pectins are still unknown. To explore the influence of extraction methods (HHP, HSHE and THE) and pH on the emulsion stabilizing properties of these pectins, many parameters, including zeta potential, apparent viscosity, light microscopy, and particle mean diameters of pectins or their emulsions (1% pectin with 42.8% refined soybean oil), were firstly determined compared with those of two commercial pectins (AP and SP). The results revealed that extraction methods have important influence on viscosities of pectins and their emulsions. The emulsions prepared by HHP extracted pectin have the smallest particle mean diameters (8.96–11.02 μm) and best emulsifying stability (100%) after centrifugation assay or 3 weeks of storage at 4 °C with the pH in the range of 3–5. The emulsions prepared by HSHE and THE extracted pectins have a similar particle mean diameters and emulsifying stabilities better than those made with AP and SP. The molecular weight distributions and morphological features, determined by HPSEC-RID and AFM, then indicated their difference at molecular level and their interactions. From the results, it could be concluded that emulsion stabilizing properties of pectin were greatly influenced by their physicochemical properties, including viscosity, molecular size and their interactions.

Extraction of pectin from navel orange peel assisted by ultra-high pressure, microwave or traditional heating: A comparison

Abstract Ultra-high pressure (UHP) was applied for pectin extraction from navel orange peel. The effects of pressure, temperature and pressure-holding time on the extraction yield and viscosity of pectin were investigated. A 2-factor 3-level design, following a single-factor experiment, was carried out to optimize the extraction parameters and the optimal conditions of UHP extraction were determined as pressure 500 MPa, temperature 55 °C, pressure-holding time 10 min. Under the optimal conditions, the yield of pectin (20.44% ± 0.64) was significantly higher than those extracted by traditional heating (15.47% ± 0.26) and microwave (18.13% ± 0.23). The physicochemical properties and rheological characteristics of pectin extracted by ultra-high pressure, traditional heating and microwave as well as commercial pectin were also compared. The results showed that the intrinsic viscosity and viscosity-average molecular weight of pectin extracted by UHP (0.7604 L/g and 3.063 × 10 5 Da) were much higher than those extracted by traditional heating (0.4276 L/g and 1.521 × 10 5 Da), microwave (0.3591 L/g and 1.230 × 10 5 Da), and the commercial pectin (0.2160 L/g and 0.663 × 10 5 Da). The same results were also obtained in the rheological characteristics, activation energy and gelling properties determination. These results clearly demonstrated that UHP is a more efficient, time saving, and eco-friendly alternative for pectin extraction from navel orange peel, especially for pectin with higher viscosity and stability.

Ultrasonic studies of polysaccharide (pectin) in aqueous media at 298.15 K

The ultrasonic velocity, density and viscosity of pectin in aqueous medium were measured at 298.15 K. The acoustical parameters such as adiabatic compressibility (β), free length (Lf), free volume (Vf), internal pressure (πi), acoustical impedance (Z), and relative association (RA), Rao’s constant (R) and Wada’s constant (W) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures. Further, some more acoustical parameters such as relaxation time (τ), absorption coefficient (α/f2) and relaxation strength (r) are calculated with various percentage of pectin has been studied which reveals interaction between the solvent and the polymer (pectin) at various concentration of the polymer. The observed values suggested the solute-solvent interaction is favored.

Dietary Pectin with High Viscosity Lowers Plasma and Liver Cholesterol Concentration and Plasma Cholesteryl Ester Transfer Protein Activity in Hamsters

We fed semipurified diets containing pectin with either a high or low in vitro viscosity at a level of 3 g/100 g air-dried diet to hamsters for 8 wk. A control group was fed cellulose and a positive control group was fed psyllium. The pectins used were a calcium-sensitive pectin (CS-pectin) that has a high viscosity and a noncalcium-sensitive pectin (NCS-pectin) that has a low viscosity. In the presence of calcium, CS-pectin has a more than 80-fold higher viscosity than NCS-pectin which offered the opportunity to investigate the possible role of viscosity in the hypolipidemic properties of pectin. The hamsters fed CS-pectin or psyllium had considerably lower plasma cholesterol concentrations (3.69 ± 0.44 and 4.21 ± 0.45 mmol/L, respectively, mean ± SD, n = 14) than those fed NCS-pectin (5.03 ± 1.15 mmol/L) or cellulose (5.72 ± 1.04 mmol/L). Differences in total plasma cholesterol were reflected in both high density lipoprotein and very low density lipoprotein cholesterol. There was no effect of fiber on low density lipoprotein cholesterol levels. Liver cholesterol concentrations paralleled the plasma cholesterol levels and were 9.91 ± 2.48 μmol/g of liver for the CS-pectin group, 15.03 ± 5.75 for the psyllium group, 17.69 ± 10.66 for the NCS-pectin group, and 25.57 ± 9.23 for the cellulose group. Fecal bile acid and neutral steroid excretion tended to be higher in the hamsters fed CS-pectin than in their counterparts fed NCS-pectin. The hamsters fed psyllium had significantly greater fecal excretions of bile acids than the hamsters fed cellulose, CS-pectin or NCS-pectin, whereas the excretion of fecal neutral sterols tended to be lower. Plasma cholesteryl ester transfer protein activity was significantly lower in the hamsters fed CS-pectin than in those fed NCS-pectin. The results of this study suggest that the viscosity of pectins may determine their cholesterolemic effect.

Effect of soil amendment with Eucalyptus rostrata leaves on activity of hydrolytic enzymes, total phenol content and onion-white-rot disease incidence

Summary The application of Eucalyptus leaf amendments to soil was not only efficient in controlling the white rot disease of onion caused by Sclerotium cepivorum, but also in production of significantly higher crop yield after 5 months growth. The pectolytic activities of healthy untreated bulbs transplanted in unamended or amended soils fluctuated between 46–51 and 43–58% reduction in viscosity of pectin, respectively. A tremendous increase in enzyme activities ranging from 88–100% was evident when bulbs became infected. The cellulolytic activities in both healthy and diseased tissues were lower than the pectolytic activities. Eucalyptus amendment was promotive to cellulases in healthy onion bulbs, but the infected ones showed a clear depression. Contrary to the high phenolics in infected tissues, the relatively low level of such compounds in bulbs of healthy uninfected onion plants most probably indicates that the soil itself was the area of struggle and inhibition of the pathogen. On the other hand, the healthy bulbs previously planted in Eucalyptus-amended soil showed higher phenolic content than their corresponding untreated ones.

A non-pectolytic protein from Phytophthora capsici that macerates plant tissue

A macerating factor was isolated from the culture filtrate of Phytophthora capsici by successive column chromatography on Sephadex G-100, hydroxylapatite cellulose and diethylaminoethyl (DEAE) cellulose. Specific activity of the macerating factor, based on protein content, increased 430-fold during the purification procedure. The final preparation neither reduced the viscosity of pectin or pectic acid solution, nor released amino acids from casein or reducing sugars from pectic substances and other polysaccharides such as xylan, mannan, araban and carboxymethyl cellulose. The macerating factor appeared to have a high molecular weight (close to or over 150 000), based on Sephadex G-100 gel filtration. The pH optimum for maceration of cucumber pericarp by the factor was 6·0 to 6·25 and its macerating activity was completely destroyed by heat (70°C for 10 min) or trypsin treatments. The purified factor had a maximum u.V. absorption at 278 nm. These results indicate that the macerating factor is a thermolabile protein, possibly an enzyme with an unknown substrate. The fungus also produced endo-type pectolytic enzymes, but these enzymes contributed only a small portion of the total macerating activity in culture filtrates.

Pectinases in Ditylenchus Dipsaci

Extracts of Ditylenchus dipsaci were most active in decreasing the viscosity of solutions of pectin N.F., less active towards pectin L.M., and least active towards Na polypectate. Optimum pH for activity of extracts was 6.0 for pectin N.F. and pectin L.M., and 5.0 for Na polypectate. Inorganic ions at a concentration of 0.2-0.3 M greatly increased the rate of reduction in viscosity of pectin N.F. solution by nematode extract. Nematode extracts retained full ability to reduce the viscosity of pectin N.F. solution when heated for 10 minutes at various temperatures through 50° C, but lost 22% of their activity at 60°, 87% at 70°, and 89% at 100°. Galacturonic acid plus several unidentified breakdown products occurred on chromatograms of nematode extract incubated with pectin N.F. solution. When nematode extract was incubated with pectin N.F. solution, reducing groups and end products of pectin trans-eliminase activity were detected in reaction mixtures by spectrophotometric methods.

Intrinsic viscosity of pectin

Intrinsic viscosity of pectin