Effect of polymeric cosolutes on calcium pectinate gelation. Part 2. Dextrans and inulin

In a continuation of the work reported in the preceding paper, the effect of chicory root inulin (M_r≈4.5 kD) and branched dextrans of M_r 67, 464 and 2000 kD on gelation of low methoxy pectin (DE 31; 2.0 wt%; pH≈2.9–3.0) on cooling from 90 to 5 °C in the presence of stoichiometric Ca²⁺ has been characterised by low amplitude oscillatory measurements of G′ and G″. As found for other polymeric cosolutes studied previously (oxidised starch, potato maltodextrin, guar gum and locust bean gum), increasing concentrations of dextran or inulin caused a progressive increase of G′ and G″ in the solution state at 90 °C (attributed to segregative interactions promoting formation of calcium-mediated ‘egg-box’ junctions between pectin chains) and a progressive reduction in final moduli at 5 °C (attributed to excessive association of calcium pectinate into large aggregated bundles), with cooling curves crossing those for calcium pectinate alone at 55 °C. For the dextran samples, the ability to promote initial association of pectin chains at high temperature decreased with increasing molecular weight (i.e. with the smallest molecules having the greatest effect, as was also found for guar gum), but the reduction in final modulus on completion of cooling to 5 °C became more pronounced. By the criterion of the decrease in the change in log G′ during cooling, the three dextran samples studied seem roughly comparable in their overall effectiveness in promoting self-association of pectin, with inulin having a substantially smaller effect. Both materials, however, are less effective than the partially depolymerised starches and galactomannans studied previously. It is tentatively suggested that this may be associated with the flexibility introduced by the presence of three single bonds in the predominant glycosidic linkages of both dextran and inulin.     

Rheological properties of mixtures of kappa-carrageenan from Hypnea musciformis and galactomannan from Cassia javanica

Mixed gels of κ-carrageenan (κ-car) from Hypnea musciformis and galactomannans (Gal) from Cassia javanica (CJ) and locust bean gum (LBG) were compared using dynamic viscoelastic measurements and compression tests. Mixed gels at 5 g/l of total polymer concentration in 0.1 M KCl showed a synergistic maximum in viscoelastic measurements for κ-car/CJ and κ-car/LBG at 2:1 and 4:1 ratios, respectively. The synergistic maximum obtained from compression tests carried out for mixed gels at 10 g/l of total polymer concentration in 0.25 M KCl was the same for both κ-car/CJ and κ-car/LBG gels. An enhancement in the storage modulus (G′) and the loss modulus (G″) was observed in the mechanical spectra for the mixtures in relation to κ-car. The proportionally higher increase in G″ compared with G′, as indicated by the values of the loss tangent (tan δ), suggests that the Gal adhere non-specifically to the κ-car network.     

Predicting the rheology of food biopolymers using constitutive models

Several constitutive models have been discussed to explain data for some foods in diluted and concentrated systems. Firstly, the theories of Rouse and Zimm, as well as rod-like theory, were used to study the conformation of the pectins in dilute solution. Among the dilute theories, the random coil theory of Zimm best explained the experimental data and suggested a certain level of intermolecular interaction present in the dilute pectin solution.

The Bird-Carreau constitutive theory with four empirical constants and zero shear limiting viscosity was used to describe the viscoelastic properties of the solutions of the guar, CMC/guar, glutenin, gluten and wheat flour doughs. The Bird-Carreau model was able to predict η and η′ in the high and low frequency regions for 1% guar solution. In the case of CMC/guar blend, the Bird-Carreau model explained steady shear and dynamic properties very well in the higher shear rate or frequency region of 1–100 s⁻¹. However, η″/ω does not tend to a zero shear constant value. The Bird-Carreau model also gave good predictions on the rheological properties of gluten and glutenin biopolymers in the free-flow region.

The polydisperse type, Doi-Edwards model, fits the experimental G′ and G″ better than the monodisperse model for 5% apple pectin dispersion. However, there is still a discrepancy between experimental and predicted values.     

Phase equilibria and gelation in gelatin/maltodextrin systems — Part I: gelation of individual components

As a prelude to studies of co-gelation with galatin, the gelation behaviour of Paselli maltodextrins SA-6 and SA-2 (DE ≈ 6 and 2, respectively) was mapped out over the experimentally-accessible range of temperature (T) and concentration (c), using a simple visual method to determine the time required for formation of a self-supporting network (t_g). For both samples, log t_g decreased linearly with log c and increased linearly with T. At equivalent temperatures and concentrations, SA-2 gelled between 20 and 60 times faster than SA-6.

Selected samples were monitored more rigorously by mechanical spectroscopy, taking t_g as the time at which elastic response (G′) became greater than viscous response (G″). In all cases the values of t_g obtained by this procedure were lower than those from visual inspection, by a constant factor of about 3·4.

The concentration-dependence of gel moduli (G′) for SA-2 and for gelatin (second-extract limed ossein; LO-2) fitted accurately to the form anticipated from cascade theory for normal polymer networks. For SA-6, by contrast, log G′ varied linearly with log c over the entire range at which measurements could be made, indicating a different mechanism of structure-formation (such as the agglomeration of short, aggregated helices).     

Effect of water-soluble and insoluble non-starch polysaccharides isolated from wheat flour on the rheological properties of wheat starch gel

Water-soluble (WSP) and insoluble non-starch polysaccharides (WIP) were isolated from wheat flour to evaluate the effects of WSP and WIP on starch gel properties. Isolated WSP and WIP were added to two types of isolated wheat starch with different amylose content at a concentration of 3% based on the dry weight of starch. 30% starch gels were prepared and stored at 5 °C for 1, 8, or 24 h. The dynamic viscoelasticity of 30% starch gels mixed with WSP and WIP was measured using parallel plate geometry, showing that WSP and WIP affected the elastic component of starch gels in opposite ways. Adding WIP increased the storage shear modulus (G′) of starch gels, while adding WSP decreased G′ and dramatically increased the loss tangent (tan δ=G″/G′).     

Stability of cumin oleoresin microencapsulated in different combination of gum arabic, maltodextrin and modified starch

Microencapsulations of cumin oleoresin by spray drying using gum arabic, maltodextrin, and modified starch (HiCap^® 100) and their ternary blends as wall materials were studied for its encapsulation efficiency and stability under storage. The microcapsules were evaluated for the content and stability of volatiles, and total cuminaldehyde, γ-terpinene and p-cymene content for six weeks. Gum arabic offered greater protection than maltodextrin and modified starch, in general, although the order of protection offered was volatiles > cuminaldehyde > p-cymene > γ-terpinene. A 4/6:1/6:1/6 blend of gum arabic/maltodextrin/modified starch offered a protection, better than gum arabic as seen from the t_1/2, i.e. time required for a constituent to reduce to 50% of its initial value. However protective effect of ternary blend was not similar for the all the constituents, and followed an order of volatiles > p-cymene > cuminaldehyde > γ-terpinene.     

Effects of Ca crosslinking on structure and properties of waterborne polyurethane-carboxymethylated guar gum films

Films from waterborne polyurethane (WPU) and carboxymethylated guar gum (CMGG) with different contents (20–80 wt%) were prepared through solution casting method, and then were crosslinked with calcium chloride. The effect of CMGG content on the miscibility, morphology and physical properties of the blend films is investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, density measurements, differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, water sensitivity measurements, solvent-swelling and tensile tests. The results reveal that the uncrosslinked films exhibit good miscibility when CMGG content is lower than 60 wt%, whereas typical “sea-island” structure occurs when the CMGG content further increases. After crosslinking with calcium ion, the blend films form a relatively dense architecture, which leads to better miscibility, higher storage modulus and thermal stability. The crosslinked films also exhibit better tensile strength (11.6–56.5 MPa) and solvent-resistance than that of the uncrosslinked films over the entire composition range. A model describing the configuration of Ca²⁺-chelating structure was proposed to illustrate the different structures of the two series of the blend films.     

Experimental and theoretical study of a truly functional biomimetic molybdenum oxotransferase analogue system

Density functional theory (DFT) computations at the B3LYP/Lanl2DZ level were used to elucidate the oxygen atom transfer (OAT) and coupled electron proton transfer (CEPT) reaction steps involved in the biomimetic catalytic cycle performed by polymer-supported Mo^VIO₂(NN′)₂ complexes [NN′ = phenyl-(pyrrolato-2-ylmethylene)-amine] with water as oxygen source, trimethyl-phosphane as oxygen acceptor and one-electron oxidising agents. The DFT method employed has been validated against experimental data [X-ray crystal structures of a NN′ ligand and a Mo^VIO₂(NN′)₂ complex as well as kinetic data]. The rate-limiting step in the forward-OAT from [Mo^VIO₂] to PMe₃ is the attack of PMe₃ at an oxo ligand with ΔG^≠ (298 K) = 64.6 kJ mol⁻¹. Dissociation of the product OPMe₃ is facile with ΔG^≠ (298 K) = 26.3 kJ mol⁻¹ giving a mono-oxo [Mo^IVO] complex which fills its coordination sphere with a further PMe₃ substrate with ΔG^≠ (298 K) = 39.2 kJ mol⁻¹. One-electron oxidation to a Mo(V) phosphane complex precedes the coordination of water/hydroxide. Additionally, the comproportionation of [Mo^VIO₂] and [Mo^IVO] to dinuclear oxo-bridged [OMo^V–O–Mo^VO] species has been calculated as the thermodynamic sink in this system and the back-OAT from dmso to mono-oxo [Mo^IVO] to give [Mo^VIO₂] has been shown to involve an equilibrium between stereoisomeric [Mo^VIO₂] complexes with an activation barrier of ΔG^≠ (298 K) = 113.1 kJ mol⁻¹.     

Correlation between sagging and shear elasticity in pectin, gelatin and polyacrylamide gels

The relationship between the height of gels determined by a sag test and their elastic shear modulus (G′) has been both investigated experimentally and simulated using a finite element analysis for the inhomogeneous deformation of gels due to gravity. It was assumed in the simulations that gels can be modeled as incompressible linear elastic materials. General relationships between the sag of gels and their elastic modulus were obtained from the simulations for slip and no-slip conditions. The relationships were tested experimentally on pectin, gelatin and polyacrylamide gels with a range of concentrations and rigidities. The good agreement between the predictions and the results shows that these gels can be modeled accurately as incompressible elastic materials. A standard 150° SAG pectin gel, which sags 23.5% in the SAG test, has G′ moduli of 429 and 379 Pa under slip and no-slip conditions, respectively.     

Pumpkin pectin: gel formation at unusually low concentration

The gel properties of high-methoxy pectin from pumpkins have been investigated to assess the potential of this material as a hard-currency export from the former Soviet Union. Comparison was made with commercial slow-set, medium-set and rapid-set pectins from citrus peel. Gels were formed by cooling pectin solutions (pH 3·0; 60% (w/w) sucrose; 5% (w/w) corn syrup) from 95°C to 25°C, and the time-temperature course of network formation was monitored by small-deformation oscillatory measurements of storage modulus (G′). At concentrations above 1% (w/w) the pumpkin pectin gave weaker gels than the other three samples, but its minimum critical gelling concentration (c₀) was found to be much lower (by at least a factor of five). Compression testing gave similar results, with pumpkin pectin giving useful breaking-stress (‘hardness’) at concentrations down to 0·5% (w/w), about a factor of two lower than for the citrus samples. Its gelation was also less rapid, giving G′ values below those of the other three samples at temperatures down to 60°C, but then setting sharply; this behaviour could be useful in avoiding ‘pregelation’ in commercial processing. The commercial slow-set pectin showed typical ‘weak gel’ properties in the solution state at 95°C, with systematic reduction in gel-like character with increasing ester content in the other samples. The rigidity of the final gels also decreased systematically through the series: rapid-set < medium-set < slow-set. These observations are tentatively ascribed to stable association of unesterified galacturonate chain segments at low pH, where electrostatic repulsion is suppressed.     

Influence of cross-linked potato starch treated with POCl3 on DSC, rheological properties and granule size

Differential scanning calorimetry (DSC), rheological measurements and granule size analyses were performed to characterize the influence of phosphorylation substitution levels on the properties of cross-linked potato starch. Phosphorus oxychloride (POCl₃) was used to produce the cross-linked potato starch. The levels of the reagent used for the reaction ranged between 40 and 5000 ppm (dwb). Storage (G′) and loss (G″) moduli were measured for a 5% (w/w) gelatinized starch dispersion stored at 20 °C for 24 h after heating at 85 °C for 30 min. The samples from 80 to 500 ppm were recognized as ‘strong gel'systems, whereas native potato starch showed ‘weak gel'behavior. Steady shear and dynamic viscoelastic properties of gelatinized starch dispersion were compared. Furthermore, granule mean diameter was measured by laser scattering for a 1% (w/w) dispersion heated at 85 °C for 30 min. The granules in the 100 ppm sample swelled to a maximum of about 2.6 times the native starch granule mean diameter.     

Thermally reversible acid-induced gelation of low-methoxy pectin

Gelation of low-methoxy pectin (DE 31.1) on cooling under acidic conditions in the absence of Ca²⁺ has been investigated by rheological measurements under low-amplitude oscillatory shear. The mechanical spectra obtained after 60 min at 5°C showed a progressive increase in solid-like response (increasing G′; decreasing tan δ; increasing frequency-dependence of η^*) as the pH was reduced from 4.0 to 1.6, with formation of a critically crosslinked network at pH 3.0 (for a polymer concentration of 3.0 wt%). By extrapolation from X-ray fibre diffraction analysis of pectic acid, it is suggested that crosslinking occurs by association of three-fold helices. At pH values between 3.5 and 2.5 there is no detectable thermal hysteresis between the sol–gel transition on cooling and gel–sol transition on heating, and both are accompanied by a sigmoidal change in optical rotation (attributed to formation and melting of three-fold order). Substantial hysteresis is, however, observed at lower and higher pH, and is attributed to extensive aggregation as electrostatic repulsion is suppressed (below pH 2.5) and slow formation of intermolecular hydrogen bonds by protonated carboxyl groups (above pH 3.5), respectively. The transition enthalpy from DSC heating scans has a maximum value of ΔH≈11 J/g at pH 3.0, but decreases sharply at lower and higher pH, with accompanying loss of a detectable transition in optical rotation. It is suggested that the chain conformation in solution at low pH is predominantly three-fold with, therefore, little conformational change on adoption of the ordered, intermolecular structure, whereas at high pH the solution conformation is predominantly two-fold, with only limited conversion to the three-fold (acid) form on cooling.     

Molecular structure and dielectric properties studies of chitin and its treated by acid, base and hypochlorite

In this work, the chitin was treated by 0.1 N HCl, 0.5 N NaOH, and 8% sodium hypochlorite. The change of the molecular structure was studied by Fourier Transform Infrared Spectroscopy (FTIR) in the wavenumber range (400–4000 cm⁻¹). The absorption bands were assigned and the crystallinity index was calculated from the ratio of the absorbance C–N band at 1378 cm⁻¹ and CH at 2925 cm⁻¹. The data indicated that, the crystallinity index of chitin is higher than that of treated chitin which is due to the hydrolysis of some acetamide group. Also, treating with alkali causes a swelling of chitin chains. The dielectric properties such as dielectric constant (ε′), dielectric loss (ε″) and AC electrical conductivity were measured and discussed as a function of frequencies (0.1 kHz–3 MHz). The dielectric constant (ε′) was decreased with increasing frequencies due to the dielectric dispersion. β-relaxation was observed and discussed from the dielectric loss (ε″). The results of AC conductivity showed that, at high frequency, the conductivity increased with increasing frequencies and its interpreted in term of hopping conduction.     

Parthenogenesis of rabbit oocytes activated by different stimuli

Oocyte activation is one of the essential elements determining the success of nuclear transfer and the subsequent development of cloned embryos both in vitro and in vivo. Experiments were conducted to optimize the protocol for oocyte activation in a regular nuclear transfer study. In vivo derived oocytes were collected at 14–15 h from New Zealand white rabbits after ovulation treatment and were activated +18 h post-ovulation treatment. Single activation agents including calcium ionophore (A23187, 5 μM, 5 min), ethanol (Eth, 7%, 7 min), and thimerosal (200 μM, 10 min) were tested. Cleavage rates were highest in the ethanol-treated group (37%) compared to other treatments (19–25%). Very low blastocyst rates (2–3%) resulted which were not significantly different among treatments (P>0.05). Combined single agent treatment (calcium stimulators) with protein kinase inhibitor, 6-DMAP were used to achieve a full oocyte activation. Both pronuclear and blastocyst formation rates were significantly higher (P<0.05) in the Eth+6-DMAP treatment group (38 and 27%) than in the other groups (16–21 and 7–9%, respectively, P<0.05). Low (0.2 mM) and high (2.5 mM) concentrations of 6-DMAP treatments with different treatment lengths (1.5 and 3.5 h) in the combined groups were also compared. Blastocyst formation and cleavage rates were greater in the high concentration with less treatment time groups (36% versus 4–20%, P<0.05). In conclusion, single activation agents, either Ca²⁺ stimulators or protein kinase inhibitors, could not fully activate mature rabbit oocytes. The best activation procedure obtained in this study was the Eth+6-DMAP combined treatment, which may be incorporated into regular nuclear transfer or cloning protocols.     

Viscoelastic properties of aqueous solutions of an exocellular polysaccharide from cyanobacteria

The viscoelastic properties of aqueous solutions of the exocellular polysaccharide of Cyanospira capsulata have been studied, over a wide range of polymer concentrations, using small deformation oscillatory, steady and transient shear methods. The viscoelastic spectra generally resemble those of an entangled network, although notable deviations can be observed in the low frequency dependence of G′ and G″. At higher polymer concentrations, the viscoelastic spectrum shows solid-like behaviour over a wide range of frequencies. The superposition of η^*(ω) and η( ) curves occurs only at low frequencies, at higher frequencies the slope of η^*(ω) is lower than that of η( ). By studying the time evolution of shear stress after the inception of a steady shear rate (stress overshoot), the recovery of non-linear properties after steady shearing flow is seen to occur after times of c. 10³ s (in the case of 1·1% w/v solutions).

The overall viscoelastic properties appear original in comparison with those of the two structurally limiting types of polysaccharide, the ‘ordered’ chain xanthan and the ‘random coil’ guar. A rationale for this ‘anomalous’ viscoelastic behaviour can be tentatively proposed in terms of flickering intermolecular cross-interactions between semi-flexible segments, which occur in addition to the usual topological constraints.     

Phase equilibria and gelation in gelatin/maltodextrin systems — Part IV: composition-dependence of mixed-gel moduli

The storage moduli (G′) of phase-separated co-gels formed by quench-cooling mixed solutions of gelatin and potato maltodextrin (Paselli SA-2 and SA-6) have been related quantitatively to the experimentally-determined concentration-dependence of G′ for the constituent polymers. Distribution of water between the phases was examined explicitly by using polymer blending laws to derive calculated moduli for gelatin-continuous and maltodextrin-continuous networks over the entire range of solvent partition. Allowance was made for the direct contribution of polymer chains, and for density differences between the phases, in calculating relative phase-volumes. The effect of gel formation prior to phase-separation was calculated using classical theory for network de-swelling. Good agreement with observed moduli for more than 30 gelatin/maltodextrin combinations was achieved using a single adjustable parameter, p (the ratio of solvent to polymer in the gelatin phase divided by the same ratio for the maltodextrin phase), with an optimum value of p ≈ 1·8 for both SA-6 and SA-2.     

“Melt-in-the-mouth” gels from mixtures of xanthan and konjac glucomannan under acidic conditions: A rheological and calorimetric study of the mechanism of synergistic gelation

The effect of acidification on a typical commercial xanthan and on pyruvate-free xanthan (PFX), alone and in gelling mixtures with konjac glucomannan (KGM), has been studied by differential scanning calorimetry (DSC) and small-deformation oscillatory measurements of storage modulus (G′) and loss modulus (G″). For both xanthan samples, progressive reduction in pH caused a progressive increase in temperature of the disorder–order transition in DSC, and a progressive reduction in gelation temperature with KGM. This inverse correlation is interpreted as showing that synergistic gelation involves disruption of the xanthan 5-fold helix, probably by attachment of KGM to the cellulosic backbone of the xanthan molecule (as proposed previously by a research group in the Institute of Food Research, Norwich, UK). Higher transition temperature accompanied by lower gelation temperature for PFX in comparison with commercial xanthan at neutral pH is explained in the same way. However, an additional postulate from the Norwich group, that attachment of KGM (or galactomannans) can occur only when the xanthan molecule is disordered, is inconsistent with the observation that gelation of acidified mixtures of KGM with PFX can occur at temperatures more than 60 °C below completion of conformational ordering of the PFX component (as characterised by DSC). Increase in G′ on cooling for mixtures of commercial xanthan with KGM at pH values of 4.5 and 4.25 occurred in two discrete steps, the first following the temperature-course observed for the same mixtures at neutral pH and the second occurring over the lower temperatures observed for mixtures of KGM with PFX at the same values of pH. These two “waves” of gel formation are attributed to interaction of KGM with, respectively, xanthan sequences that had retained a high content of pyruvate substituents, and sequences depleted in pyruvate by acid hydrolysis. At pH values of 4.0 and lower, gelation of mixtures of KGM with commercial xanthan followed essentially the same temperature-course as for mixtures with PFX, indicating extensive loss of pyruvate under these more strongly acidic conditions. Mixtures prepared at pH values in the range 4.0–3.5 gave comparable moduli at room temperature (20 °C) to those obtained at neutral pH, but showed substantial softening on heating to body temperature, suggesting possible applications in replacement of gelatin in products where “melt-in-the-mouth” characteristics are important for acceptability to the consumer.     

Conductance and relaxations of gelatin films in glassy and rubbery states

The dielectric constant, ′, and the dielectric loss, ″, for gelatin films were measured in the glassy and rubbery states over a frequency range from 20 Hz to 10 MHz; ′ and ″ were transformed into M* formalism (M*=1/(′−i″)=M′+iM″; i, the imaginary unit). The peak of ″ was masked probably due to dc conduction, but the peak of M″, e.g. the conductivity relaxation, for the gelatin used was observed. By fitting the M″ data to the Havriliak–Negami type equation, the relaxation time, τ_HN, was evaluated. The value of the activation energy, E_τ, evaluated from an Arrhenius plot of 1/τ_HN, agreed well with that of E_σ evaluated from the DC conductivity σ₀ both in the glassy and rubbery states, indicating that the conductivity relaxation observed for the gelatin films was ascribed to ionic conduction. The value of the activation energy in the glassy state was larger than that in the rubbery state.     

Depletion of intracellular Ca2+ store itself may be a major factor in thapsigargin-induced ER stress and apoptosis in PC12 cells

The mechanisms of intracellular calcium store depletion and store-related Ca²⁺ dysregulation in relation to apoptotic cell death in PC12 cells were investigated at physiological temperatures with a leak-resistant fluorescent indicator dye Fura-PE3/AM by a cooled CCD imaging analysis system. Electron microscopic observations have shown thapsigargin (TG; 100 nM)-induced apoptosis in PC12 cells. Thorough starvation of stored Ca²⁺ by BAPTA/AM (50 μM), or La³⁺ (100 μM) enhanced while dantrolene (100 μM) attenuated the TG-induced apoptosis by preventing a calcium release from internal stores. An immunoblotting analysis revealed an enhanced expression of GRP78, the hallmark of endoplasmic reticulum (ER) stress when cells were treated by TG along with BAPTA/AM. These results indicate that the depletion of the intracellular Ca²⁺ stores itself induces the ER stress and apoptosis in PC12 cells without any involvement of the capacitative calcium entry (CCE) or a sustained elevation of intracellular Ca²⁺ concentrations ([Ca²⁺]_i).     

Development and Characterization of Pectinate Micro/Nanoparticles for Gene Delivery

The aim of this study was to investigate the possibility of using pectinate micro/nanoparticles as gene delivery systems. Pectinate micro/nanoparticles were produced by ionotropic gelation. Various factors were studied for their effects on the preparation of pectinate micro/nanoparticles: the pH of the pectin solution, the ratio of pectin to the cation, the concentration of pectin and the cation, and the type of cation (calcium ions, magnesium ions and manganese ions). After the preparation, the size and charge of the pectin micro/nanoparticles and their DNA incorporation efficiency were evaluated. The results showed that the particle sizes decreased with the decreased concentrations of pectin and cation. The type of cations affected the particle size. Sizes of calcium pectinate particles were larger than those of magnesium pectinate and manganese pectinate particles. The DNA loading efficiency showed that Ca-pectinate nanoparticles could entrap DNA up to 0.05 mg when the weight ratio of pectin:CaCl₂:DNA was 0.2:1:0.05. However, Mg-pectinate could entrap only 0.01 mg DNA when the weight ratio of pectin:MgCl₂:DNA was 1:100:0.01 The transfection efficiency of both Ca-pectinate and Mg-pectinate nanoparticles yielded relatively low levels of green fluorescent protein expression and low cytotoxicity in Huh7 cells. Given the negligible cytotoxic effects, these pectinate micro/nanoparticles can be considered as potential candidates for use as safe gene delivery carriers.