Pectin Gels Research Articles

Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions

Low methoxyl pectin is known to gel with divalent cations (e.g. Ca2+, Zn2+). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca2+ binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step.

Fentanyl in a pectin gel treating breakthrough pain in vertebral compression fracture due to multiple myeloma: A descriptive study of three cases.

Breakthrough pain (BTP) currently represents a challenge for health professionals dedicated to the treatment of pain. In this descriptive 1-year follow-up study on three patients with BTP from vertebral crush, in the context of multiple myeloma, the authors have observed the great either efficacy or tolerability profile of fentanyl pectin nasal spray. The most relevant findings in this study were better adherence to treatment compared to previously opioids and also great personal satisfaction. Because of common pathophysiological mechanism for noncancerous pain of bone origin, these good results could open the door to investigation of the use of this drug in this patient's group.

Calcium pectinate gel beads obtained from callus cultures pectins as promising systems for colon-targeted drug delivery

Low methyl-esterified pectins obtained from the cell walls of the campion (SV, SV>300), tansy (TV, TV>300) and duckweed (LM, LM>300) callus cultures and apple pectin (AP, Classic AU 701) were used as the carriers for colon delivery of prednisolone. The pectins with molecular weight more than 300kDa (SV>300, TV>300, LM>300) formed gels which exhibited the higher gel strength. The higher gel strength of these gels appeared to be related to the higher Mw and the lower degree of methylesterification (DE) of these pectins. Release aspects of prednisolone in the simulated gastric (pH 1.25), intestinal (pH 7.0) and colonic (pH 7.0+pectinase) media were investigated. The LM-5%, AP-3% and AP-5% beads destroyed in simulated intestinal medium probably due to the higher DE of the LM and AP pectins. The SV>300-3% and TV>300-3% prednisolone loaded bead systems showed a high stability at pH 1.25 and pH 7.0. Prednisolone release occurred in a larger extent in colonic medium due to the enzymatic erosion of the beads. The SV>300-3% and TV>300-3% particles showed a more controlled release that appeared to be related to the lower DE, rhamnogalacturonan content, rhamnogalacturonan I branching and the higher linearity and Mw of the TV>300 and SV>300 pectins, as well as to the higher gel strength. This in vitro study suggests that calcium pectinate gel beads obtained from callus cultures pectins can be proposed as potential systems for colon-targeted drug delivery.

Emulsion templated microencapsulation of dandelion (Taraxacum officinale L.) polyphenols and β-carotene by ionotropic gelation of alginate and pectin

This research underlines the potential of employing emulsion/internal gelation encapsulation in alginate and pectin hydrogels for the simultaneous delivery of hydrophilic (polyphenols from dandelion (Taraxacum officinalis L.) extract) and lypophilic (β-carotene) compounds. The approach of reinforcing alginate and pectin hydrogels by whey proteins and hydroxypropyl methylcellulose (HPMC) as the carriers for the design of microencapsulated delivery systems was also evaluated. Comprehensive characterization of the morphological properties, particle size, encapsulation efficiency, interactions and release in gastrointestinal conditions was achieved. A simple and effective procedure based on the ionic gelation of emulsions for microencapsulation of polyphenols and β-carotene was developed, allowing formulation of micro-sized particles ranging ≤800 μm, which retained their spherical morphological properties upon drying. Incorporation of whey proteins and HPMC in the alginate gel contributed to better encapsulation parameters i.e. the morphological properties and encapsulation efficiency in relation to plain alginate particles. The combination of alginate with whey proteins as the carrier matrix arised as the optimal delivery system, owing to its regular, spherical shape, high encapsulation efficiency of total polyphenols (77,35%) and very good retention of hydroxycinnamic acids (89,14%), while the binary mixture of alginate and HPMC as the carrier enabled the best (prolongued) release profile of these compounds from the formulated microparticles in simulated gastrointestinal fluids.

Gastroretentive Drug Delivery System of Famotidine: Formulation and In Vitro Evaluation of Oil Entrapped Calcium Pectinate Gel Beads

In the present research envisaged was to prepare gastroretentive beads to increase the retention time in stomach and to modulate the release pattern from the gel beads. The aim of the research work to study the compatibility between drug and other polymers by differential scanning calorimetric analysis, preparation of cod liver oil entrapped calcium pectinate gel beads of famotidine by emulsion gelation method and its evaluation. The gel beads were prepared by employing low methoxy pectin with degree of esterification less than 50% alone and with hydrophilic co polymers carbopol 934P, hydroxypropyl methylcellulose K15M and polycarbophil to study the effect of these co polymers on drug release. The prepared gel beads were subjected for various evaluations like topographical study of whole and dissected bead, percent drug entrapment efficiency, buoyancy and in vitro drug release study in conventional and modified flow through dissolution methods. The prepared beads showed ideal buoyancy, low methoxy pectin gel matrix could not sustain the drug release and presence of co polymers demonstrated sustained release. These observations suggested that cod liver oil entrapped calcium pectinate beads were promising as a carrier for intragastric floating drug delivery of famotidine.

Alkaline phosphatase immobilization on spherical pectin gel particles

Spherical gel particles from apple pectin and amidated citrus pectin with a low degree of methyl esterification were obtained by ionotropic gelation in the presence of calcium ions. A commercial preparation of alkaline phosphatase from bovine intestinal mucosa was used for enzyme immobilization by physical adsorption on pectin particles and by incorporation into a hydrogel. Alkaline phosphatase immobilized on pectin gels retained 21–55% of the initial activity. Release of the immobilized enzyme from the gel particles into solutions modeling the physiological conditions in different parts of the gastrointestinal tract was investigated. Alkaline phosphatase desorbed from pectin particles was shown to dephosphorylate bacterial lipopolysaccharide.

Effect of the aerated structure on selected properties of freeze-dried hydrocolloid gels

Abstract The ability to create diverse structures and studies on the effect of the aerated structure on selected properties with the use of freeze-dried gels may provide knowledge about the properties of dried foods. Such gels can be a basis for obtaining innovative food products. For the gel preparation, 3 types of hydrocolloids were used: low-methoxyl pectin, a mixture of xanthan gum and locust-bean gum, and a mixture of xanthan gum and guar gum. Gels were aerated for 3 and 7 min, frozen at a temperature of −45°C 2 h−1, and freeze-dried at a temperature of 30°C. For the samples obtained, structure, porosity, shrinkage, rehydration, and colour were investigated. It was shown that the type of the hydrocolloid and aeration time influence the structure of freeze-dried gels, which determines such properties of samples as porosity, shrinkage, density, rehydration, and colour. The bigger pores of low-methoxyl pectin gels undergo rehydration in the highest degree. The delicate and aerated structure of gels with the mixture of xanthan gum and locust-bean gum was damaged during freeze-drying and shrinkage exhibited the highest value. Small pores of samples with the mixture of xanthan gum and guar gum were responsible for the lower rehydration properties, but the highest porosity value contributed to the highest lightness value.

Characterization of microstructure, viscoelasticity, heterogeneity and ergodicity in pectin–laponite–CTAB–calcium nanocomposite hydrogels

In order to customize the viscoelastic properties of pectin gels, it is necessary to work on a composite platform. Herein, the gelation kinetics, and viscoelastic characterization of anionic polysaccharide pectin dispersion prepared in presence of nanoclay laponite are reported using dynamic light scattering and rheology measurements. The ratio Rg/Rh (Rg and Rh are radius of gyration and hydrodynamic radius respectively) determined from light scattering data revealed the presence of random coils of pectin chains inside the gel matrix. When nanoclay laponite was added to the pectin chains solution, two-phase separation was noticed instantaneously. Therefore, the surfactant cetyltrimethylammonium bromide [CTAB] was added to exfoliate the clay platelets in the dispersion, and also in its gel phase. The exfoliating agent cetyltrimethylammonium bromide ([CTAB]≈cmc/10) helped to enhance the homogeneity and stability of the pectin–clay sols and gels. The storage and loss moduli (G′ and G″) of the composite gel changed significantly as function of nanoclay laponite content for concentration up to 0.03% (w/v) causing the softening of the gels (gel strength reduced by close to 50%) compared to pectin–calcium gel. However, as the concentration of nanoclay laponite was maintained between 0.01% and 0.03% (w/v), the gel rigidity (G′) recovered by 30% (35–45Pa). The transition from ergodic to non-ergodic state occurred during sol-gel transition owing to the presence of the nanoclay laponite. The gelation time was not too different from the ergodicity breaking time. Thus, the presence of nanoclay laponite in such minute concentration is shown to cause considerable change in the thermo-physical property of the composite gels. This material property modulation will facilitate designing of soft gels having storage modulus continuously varying in the wide range of 10–70Pa while keeping the gelation temperature mostly unaltered.

Zooming in: Structural Investigations of Rheologically Characterized Hydrogen-Bonded Low-Methoxyl Pectin Networks.

Self-assembled hydrogen-bonded networks of the polysaccharide pectin, a mechanically functional component of plant cell walls, have been of recent interest as biomimetic exemplars of physical gels, and the microrheological and strain-stiffening behaviors have been previously investigated. Despite this detailed rheological characterization of preformed gels, little is known about the fundamental arrangement of the polymers into cross-linking junction zones, the size of these bonded regions, and the resultant network architecture in these hydrogen-bonded materials, especially in contrast to the plethora of such information available for their well-known calcium-assembled counterparts. In this work, in concert with pertinent rheological measurements, an in-depth structural study of the hydrogen-bond-mediated gelation of pectins is provided. Gels were realized by using glucona-delta-lactone to decrease the pH of solutions of pectic polymers that had a (blockwise) low degree of methylesterification. Small-angle X-ray scattering and transmission electron microscopy were utilized to access structural information on length scales on the order of nanometers to hundreds of nanometers, while complementary mechanical properties were measured predominantly using small amplitude oscillatory shear rheology.

Pectin/anhydrous dibasic calcium phosphate matrix tablets for in vitro controlled release of water-soluble drug

Different pectin/anhydrous dibasic calcium phosphate (ADCP) matrix tablets have been developed in order to obtain controlled release of a water-soluble drug (theophylline). Swelling, buoyancy and dissolution studies have been carried out in different aqueous media (demineralized water, progressive pH medium, simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid), to characterize the matrix tablets. When the pectin/ADCP ratio was ≥0.26 (P1, P2, P3 and P4 tablets) a continuous swelling and low theophylline dissolution rate from the matrices were observed. So, pectin gel forming feature predominated over the ADCP properties, yielding pH-independent drug release behavior from these matrices. On the contrary, pectin/ADCP ratios ≤0.11 (P5 and P6 tablets) allowed to achieve drug dissolution pH dependent. Consequently, the suitable selection of the pectin/ADCP ratio will allow to tailor matrix tablets for controlled release of water-soluble drugs in a specific manner in the gastrointestinal tract.

Biomimetic hybrid scaffolds for osteo-chondral tissue repair: Design and osteogenic differentiation of human placenta-derived cells (hPDC).

A novel functionally-graded hybrid (FGHY) scaffold was designed and developed with a load-bearing structure represented by a PU foam loaded with a graded composition of CaPs (biomimetic component) and pectin gel as cell carrier. hPDC populations encapsulated in pectin gels and injected into the FGHY scaffolds demonstrated the ability to differentiate toward the osteogenic lineage. The ability of these biomimetic hybrid scaffolds to stimulate cell adhesion and proliferation and to support differentiation of hPDCs make these scaffolds excellent candidates for an use in bone regeneration.

Thermogravimetric analysis of pectin gels

A weight loss and speed change occurring in gels of citrus and apple pectin of different degree of esterification and the effect of sodium citrate on the mass loss of low pectin gel are studied by thermographic technique constant heating rate. The dependence of the degree of weight change on temperature of gel of citrus and apple pectin with high and low degree of esterification is determined

Comparison of Acidic and Enzymatic Pectin Extraction from Passion Fruit Peels and Its Gel Properties

AbstractThe influences of extractor concentration, extraction temperature and time on the yield of pectin and degree of esterification (DE) were investigated by the acidic and enzymatic extraction methods. Citric acid and Celluclast were selected as pectin extractors for environmentally friendly reasons. The peels of yellow passion fruit using the acidic and enzymatic extraction methods gave pectin yield of 7.16 and 7.12%, and DE of 71.02 and 85.45% in the optimized condition of extraction time of 102 min with citric acid concentration of 0.19% (w/w) at 75C and Celluclast concentration of 1.67% (w/w) at 61.11C, respectively. The enzymatic extraction method has greater capability of producing high methoxyl pectin. The morphological features of fruit peel powder and the extracted pectin examined by scanning electron microscopy suggested that the nanostructure of wet passion fruit pectin was dependable on the type of extraction process. The formed pectin gel also has pseudoplastic liquid behavior and its viscosity was greatly affected by sugar.Practical ApplicationsPectin has been intensively used as natural gelling agent and stabilizer to alter rheological properties in food ingredients by most food processing industries to achieve desired textural quality. Pectin could be recovery from fruit wastes. The conversion of passion fruit peel into pectin offers great scope for utilization. Citric acid and enzymatic extraction methods are effectively used for pectin extraction which may be of interest by pectin industry and consumer with these eco‐friendly processing technology with no using harmful chemicals. Furthermore, scientific work of this study such as the optimized condition, morphological features of extracted pectin and pectin gel formation contributes valuable information on pectin, which could be beneficial for pectin industry improving the process quality of pectin as well as process profitability.

Process development and simulation of pectin extraction from orange peels

This work presents the sizing and scheduling of a semi-batch plant for the production of 348ton/year of pectin from Valencia orange peels under optimum experimental extraction conditions (90°C, 75min, pH 1.5). The designed plant included acid hydrolysis of peels, filtration of the hydrolyzed suspension, alcoholic precipitation of pectin, gel pressing, gel drying, and pectin size reduction. Calculations of processing times and size of units were done with Microsoft Excel® and Aspen Plus v7.3®. Characteristic dead times in the precipitation stage of the conventional processes were eliminated by implementing two out-of-phase hydrolysis stages, which lowers the batch size and the dimensions of hydrolysis tanks; this is an important improvement given the technical difficulties that may arise when handling large amounts (e.g., above 1ton) of highly-viscous suspensions (e.g., above 100cP), such as those present in the hydrolysis stage of pectin extraction. Up to 76% ethanol recovery was achieved by means of the operation of a continuous distillation column. Furthermore, rheological behavior of the liquid obtained from the hydrolysis of orange peels in acidic media, as well as the drying of pectin gels was modeled in this contribution. In particular, the rheological analysis allowed a more realistic estimation of energy demands for heat transfer and agitation in the hydrolysis stage, which resulted to be the process bottleneck and determined the cycle time and, consequently, defined the equipment size.

How to let go: pectin and plant cell adhesion.

Plant cells do not, in general, migrate. They maintain a fixed position relative to their neighbors, intimately linked through growth and differentiation. The mediator of this connection, the pectin-rich middle lamella, is deposited during cell division and maintained throughout the cell’s life to protect tissue integrity. The maintenance of adhesion requires cell wall modification and is dependent on the actin cytoskeleton. There are developmental processes that require cell separation, such as organ abscission, dehiscence, and ripening. In these instances, the pectin-rich middle lamella must be actively altered to allow cell separation, a process which also requires cell wall modification. In this review, we will focus on the role of pectin and its modification in cell adhesion and separation. Recent insights gained in pectin gel mechanics will be discussed in relation to existing knowledge of pectin chemistry as it relates to cell adhesion. As a whole, we hope to begin defining the physical mechanisms behind a cells’ ability to hang on, and how it lets go.

Effects of amidation and/or methylesterification of pectin on aroma release at different calcium concentration

Four different types of low methoxyl pectins (LMPs) were prepared via amidation and methylesterification to investigate the release of 14 aroma compounds from different pectin gel systems at different calcium concentration. The release of aroma compounds was determined using static headspace gas chromatography analysis. Amidation and amidation combined by methylesterification increased aroma release from LMP gels compared to the non-treated ones at diverse calcium concentration, except amidated LMP at 0.09% calcium. On the other hand, methylesterified LMP reduced the release of most aroma compounds at 0.03–0.09% calcium concentration. Furthermore, treatment with pectin methylesterase increased the release of aroma compounds from amidated pectin but reduced their release from nonamidated pectin. Comparison of the release of a series of esters with different numbers of carbon atoms revealed increased release of compounds with up to six carbons, and then a decrease of those with up to ten in LMP, amidated LMP, and amidated and methylesterified pectin gel systems.

Fast production of high-methoxyl pectin aerogels for enhancing the bioavailability of low-soluble drugs

Aerogels are outstanding materials with high porosities, low densities and large surface areas. Moreover, polysaccharide aerogels e.g. pectin aerogels, are gaining interest due to their biodegradability and biocompatibility, which makes them interesting materials for medical, pharmaceutical or food applications. In this research we propose a new method for the gelation of high-methoxyl pectin. In later continuation those aerogels will be proposed as carriers to enhance the dissolution of poorly soluble drugs. Nifedipine was used as model drug. The aim of the research was to investigate two methods for the drug loading; first by adding the drug during the sol–gel process and second by supercritical adsorption. By the novel gelation method, the overall aerogel production time was shorter. In addition, prepared aerogels possessed highest yet reported surface area for high-methoxyl pectin monolithic aerogels, namely around 390m2g−1. Drug loading during the sol–gel process was higher (22%), however also supercritical adsorption gave comparably good results (13%) according to the low solubility of nifedipine. Nifedipine release was controlled over 12h and 100% (60mg) drug release was achieved in this period.

Differential Property of Cationic and Anionic Calcium Ion Cross-linked Pectin Gels

Pectin is a branched polysaccharides found in the cell wall of the plants and commonly used in food industry as a gelling agent, emulsifier or stabilizer. The effect of calcium chloride on the gelation of pectin dispersions was studied using rheology and light scattering measurements. Addition of calcium induced the gel formation in pectin dispersions follows egg-box crosslink mechanism. Zeta potential measurements revealed the formation of cationic and anionic pectin gels on concentration of calcium. The cationic gels had higher rigidity compared to anionic gels. The sol-gel transition has been investigated for pectin-calcium system from the structure factor data which indicated cationic gels undergo transition earlier compared to anionic ones. The gelation time was determined from rheology and viscosity experiments and found to be less for cationic gels.

Research of technological properties of biochemically modified pectin substances

The paper presents the results of experimental studies to determine the mass fraction of effectors – calcium ions, which allow you to adjust the solubility of low-esterified pectin gel to create structural compositions depending on the time and concentration of enzymatic de-esterification of pectin in the solution. Injection of calcium salts in a mixture having influence on both the solubility and the viscosity characteristics and the gelling ability of modified pectin solution. With injection of calcium salts in solution of citrus pectin it is observed their different behavior depending on the nature of amount of salts and introduced pectin. With an increase in the mass fraction of low-esterified pectin and calcium salts take place a gradual increase in viscosity of the solution with a transition to the dense gel, but higher concentrations of calcium lead to syneresis process. It has been established that structural and mechanical properties of the gel affect the amount and type of pectin, as well as in its content in the composition of calcium ions. It is shown that low-esterified pectin substances may make up the thermoreversible gels. Anions of calcium salts significantly affect the structuring of the pectin and calcium cation allows receiving a variety of gel compositions with a mass fraction of pectin is not less than 0,6 g per 100 cm 3 , which is important for producing structured and canned foods.

Study of moisture structurization and binding form changes in pectin gels by differential scanning calorimetry

Термоциклуванням досліджували зміни структури та вологоутримуючу здатність зразків пектинових гелів з різним рецептурним складом за допомогою диференціально-сканувальної калориметрії, циклічно нагріваючи їх та заморожуючи. Доведено вплив основних рецептурних компонентів на збільшення кількості зв¢язаної води, стійкість структури та тривалість гелеутворення в пектинових гелях, що відбуваються під час нагрівання та заморожування.