Physicochemical Properties Of Pectin Research Articles

Hot-air drying vs. lyophilization of sugar beet flakes for efficient pectin recovery and influence of extraction conditions on pectin physicochemical properties

This study assessed the influence of drying pretreatment and extraction conditions (type of acid and particle size of plant material) on the yield and physicochemical properties of pectin from sugar beet flakes resulted as by-product of sugar beet processing in the sugar industry. The results indicated that the drying conditions (hot-air drying and lyophilization) affected the extraction yield, the chemical composition of pectin, its color, degree of methylation and acetylation, molecular weight, and its rheological and emulsifying properties. The best results for pectin yield (16.20%), galacturonic acid content (91.19 g/100 g), degree of methylation and acetylation (66.93 and 23.87%), and molecular weight (3.89 × 105 g/mol) were obtained when sugar beet flakes were pretreated by hot-air drying, and the extraction was made with citric acid using plant material with particle sizes of 125–200 μm. This pectin also had high emulsion activity (51.42%) and emulsion stability (88.03%). The FT-IR spectra were similar, while pectin thermal behavior was affected by the drying pretreatment and extraction conditions. The results of this study showed that from this by-product of the sugar industry it can be extracted high quality pectin with rheological and emulsifying properties that are superior to commercial citrus and apple pectin.

Extraction of pectin from jelly fig shell using microwave heating extraction: pectin physicochemical properties and antioxidant activities

Abstract Jelly fig is a crop of high economic value; however, the processing by-product of jelly fig, “jelly fig shell”, is not well utilized. In this study, jelly fig shell pectin was extracted through the microwave extraction technique. Then, galacturonic acid content, degree of esterification, molecular weight, functional group properties, and antioxidant activity were determined. The highest pectin yield (21.6 ± 0.1 %) was obtained at 200 mM citric acid and microwave power of 800 W, with extraction time of 4 min. The content of galacturonic acid in pectin was greater than 65 %, which meets the specifications of food-grade pectin. In terms of antioxidant ability, the IC50 of 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging rate of jelly fig shell pectin was 175.1 μg/mL. These results suggest that, comparing to the extracted jelly fig seed pectin, jelly fig shell has stable quality under more desirable extraction conditions, and has better physicochemical properties.

Effect of H2O2-assisted ultrasonic bath on the degradation and physicochemical properties of pectin

The effects of H2O2-assisted ultrasonic bath degradation technology on pectin were investigated. The degradation efficiency with different pectin concentrations, H2O2 concentrations, ultrasonic power, and ultrasonic time was analyzed. The results showed that pectin concentration was negatively correlated with the degradation efficiency of pectin, while, H2O2 concentration, ultrasonic power, and ultrasonic time were positive correlated with the degradation efficiency. Besides, the apparent viscosity and viscoelasticity of the degraded pectin decreased significantly. The antioxidant activity increased after the H2O2-assisted ultrasonic bath treatment. The results of FTIR, NMR, laser particle size, SEM, XRD, and AFM analysis indicated that the degradation treatment did not destroy the main structure of pectin. The average particle size and crystallinity of pectin decreased. The degree of aggregation and the height of the molecular chain decreased significantly. In conclusion, the H2O2-assisted ultrasonic bath degradation technique could effectively degrade pectin. This study provided a comprehensive analysis of the degradation of pectin under H2O2-assisted ultrasonic bath, which will be beneficial to further develop H2O2-assisted ultrasonic bath techniques for pectin degradation.

Understanding the impact of pectin on browning of polyphenol oxidation system in thermal and storage processing

Browning of some processed fruit products was affected not only by polyphenol oxidation but also by cell wall polysaccharides (pectin). The study was performed to understand the mechanism of browning in the pectin system. The catechin/chlorogenic acid oxidation system in three pectins significantly enhanced their browning during thermal storage with pectin structure- and concentration-dependent. Particularly, the structural and physicochemical properties of pectin were examined to determine its effects on the kinetics of polyphenol oxidation and the stability of free polyphenols. Moreover, pectin impacted the fluorescence characteristics of polyphenols by cross-linking with the aromatic ring of polyphenols. In turn, the interaction between polyphenols and pectin impacted the chemical bond vibration of pectin, thereby affecting its optical features and browning. The correlation analysis revealed that the monosaccharide composition, Ratio 1, Ratio 2, Ratio 3, methyl esterification, ζ-potential, and polydispersity index of pectin were significantly correlated with the browning of the pectin-polyphenol oxidation system.

Structural, functional and physicochemical properties of pectin from grape pomace as affected by different extraction techniques

Pectin from grape pomace (Vitis vinifera var. Fetească Neagră and Vitis vinifera var. Rară Neagră) was extracted by using different extraction techniques (conventional, microwave-assisted and pulsed ultrasound-assisted extraction). Microwave-assisted extraction showed highest yield (11.2 %) for Rară Neagră pectin, while conventional extraction presented highest yield (9.9 %) for Fetească Neagră pectin. The yield was directly correlated with the galacturonic acid content, degree of esterification, molecular weight and functional features (water-holding, oil-holding and water-swelling capacity, emulsifying properties and rheological behavior of pectin emulsions). In addition, the FT-IR, morphological structure, thermal analysis and emulsion properties of obtained pectin samples from different extraction techniques revealed dissimilar results by comparing with commercial pectin.

Effect of solution pulsed plasma process on the degradation and physicochemical properties of pectin

Pectin was degraded by solution pulsed plasma (SPP). The impacts of discharge voltage and the distance between the electrodes on pectin degradation and its steady shear flow behavior and characterization were investigated. The results showed that the influence of the discharge voltage was higher than that of the distance between the electrodes. The stronger discharge voltage and the narrower distance between the electrodes presented the lower intrinsic viscosity, the greater shear-thinning capacities, and the stronger viscoelastic behavior. FT-IR and 1H NMR analysis demonstrated that SPP treatment did not damage the main structure of pectin. XRD, SEM and HPSEC-MALL analysis revealed that the crystallinity, Mw and <S2>z1/2 of pectin gradually decreased with the increasing discharge voltage and decreasing the distance between the electrodes. The depolymerized pectin molecules exhibited a hard sphere conformation in the aqueous solution. A higher degradation effect had a greater influence on the conformation of pectin.

Gelation behavior and mechanism of Nicandra physalodes (Linn.) Gaertn. seeds pectin induced by Glucono–delta–lactone

In this study, the physicochemical properties of pectin from Nicandra physalodes (Linn.) Gaertn. seeds (NPGSP) were analysed firstly, and the rheological behavior, microstructure and gelation mechanism of NPGSP gels induced by Glucono–delta–lactone (GDL) were investigated. The hardness of NPGSP gels was increased from 26.27 g to 226.77 g when increasing GDL concentration from 0 % (pH = 4.0) to 1.35 % (pH = 3.0), and the thermal stability was improved. The peak around 1617 cm−1 was decreased as the adsorption peak of the free carboxyl groups was attenuated with addition of GDL. GDL increased the crystalline degree of NPGSP gels, and its microstructure exhibited more smaller spores. Molecular dynamics was performed on systems of pectin and gluconic acid (GDL hydrolysis product), indicating that inter–molecular hydrogen bonds and van der Waals forces were the main interactions to promote gels formation. Overall, NPGSP has the potential commercial value for developing as a thickener in food processing.

Preparation of amidated pectins through enzymatic method: Structures, hydrogel properties and its application potential in fat substitutes

In this paper, α-alanine and β-alanine were used as modifiers to prepare α-alanine amidated pectin (α-AP) and β-alanine amidated pectin (β-AP) through enzymatic method. The effects of alanine and its isomer on the amidation degree and physicochemical properties of pectin were studied. Fourier transform infrared spectrum, proton nuclear magnetic resonance analysis, X-ray photoelectron spectrum and elemental analysis indicated that the amino groups from α-C and β-C could be aminated with the carboxyl group of pectin to form the corresponding aminated pectin. The alanine grafting ratio of α-AP and β-AP were 21.99% and 18.92%, respectively. The results showed that the dynamic viscosity of β-AP was significantly higher than that of α-AP due to the influence of amino acid side chain. However, due to the higher alanine grafting ratio of α-AP, the strength of hydrogel prepared by α-AP was higher than that of β-AP, and it also has the highest elastic modulus and swelling capacity. In addition, pectin, as a carbohydrate-based fat substitute, has been widely used in the field of food to simulate the smooth and delicate taste of fat. Compared with High methoxy pectin (HMP) and β-AP, α-AP had better colloid stability and smaller hydrogel particles in the composite system. The results provide references for the application of amidated pectin in low-fat food.

The effect of high humidity hot air impingement blanching on the changes in cell wall polysaccharides and phytochemicals of okra pods.

Okra pods contain heat-sensitive substances, such as phenolic compounds and other phytochemicals that can be degraded when okra pods are subjected to heat treatment. The understanding of the impact of high humidity hot air impingement blanching (HHAIB) on the changes in physicochemical properties of polysaccharides and phytochemicals of okra pods is of great importance because over-blanching may result in cell membrane disruption and changes in biologically active compounds under prolonged exposure to the thermal treatment. Therefore, the present study aimed to investigate the effect of HHAIB on the changes in physicochemical properties of pectins and phytochemicals extracted from okra pods. Both the HHAIB time and method of extraction influenced their physicochemical characteristics and biological activity. Pectin fractions subjected to HHAIB were composed of polygalacturonic acid, rhamnogalacturonan, glucomannan, galactan, mannose, arabinose, rhamnose, calcium pectate and arabinogalactan. The contents of total phenolics, total flavonoids and antioxidant activity of extracts mostly increased during HHAIB (i.e. up to 19.0%, 13.2% and 35.3%, respectively). However, HHAIB reduced the chlorophyll-a (up to 55.7%) and lycopene (up to 52.6%) contents of okra pods. The acquired knowledge may be useful for better understanding and optimization of technologies based on HHAIB treatment. The HHAIB treated okra can be a promising natural alternative in different applications, including its use as a replacement of some ingredients in food or non-food systems as a result of richness in polysaccharides and polyphenols, as well as high antioxidant properties. © 2022 Society of Chemical Industry.

Comparison of physicochemical properties of pectin Extracted from apple pomace by microwave and high temperature acid treatment: optimization by surface – Response

Comparison of physicochemical properties of pectin Extracted from apple pomace by microwave and high temperature acid treatment: optimization by surface – Response

Structure, physicochemical characterisation and properties of pectic polysaccharide from Premma puberula pamp.

Food manufacturers are increasingly demanding novel natural emulsifiers. In the current study, physicochemical properties of pectin were obtained from Premna puberula Pamp. (PP) were studied systematically to develop natural emulsifiers further. The structural characterisation was performed using gas chromatography-mass spectrometry, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance. We discovered that PP was high-methoxy pectin with rich arabinose and galactose side chains (Ara + Gal)/Rha = 3.27 and Mη = 292.25 kDa) and was mainly amorphous material with a small amount of microcrystalline structure. Moreover, PP exhibited an excellent thermal stability and shear thinning phenomenon, a characteristic of non-Newtonian fluids. It exhibited significantly considerable emulsification performance. Additionally, its gelling properties and antioxidant effects were better than commercial pectins (citrus pectin and apple pectin). Therefore, P. puberula containing homogalacturonan (32.57%) and rhamnogalacturonan-I (36.45%) is a potential source of natural emulsifier and rheological modifier, which can be used in a variety of products.

Effects of different extraction methods on structural and physicochemical properties of pectins from finger citron pomace

The functionality and property of pectin are correlated with its structure which is affected by the extraction method used. In this study, three different methods of extracting pectin, the microwave-assisted extraction (MAE), the ultrasonic-assisted extraction (UAE) and the conventional heating extraction (CHE), were used at three different temperatures with both an acid and alkali extraction solution. It was found that temperature mainly influenced pectin yield, while pectin structures and physicochemical properties were affected by the pH condition and extraction technology. The alkali-extraction with MAE and UAE at short time promoted the yield of low-ester pectin. Monosaccharide composition analysis showed a high galacturonic acid (GalA) content in the pectin derived from MAE and UAE. The high viscosity and desirable viscoelastic properties of the acid-MAE pectin were due to its large molecular weight and particle size. The results contribute to our understanding of the association among pectin extraction, structure and properties.

The concentration-modified physicochemical surface properties of sodium carbonate-soluble pectin from pears (Pyrus communis L.)

Cross–linking and gelation are important abilities affecting pectin functionality. Pectin concentration, pH and the composition of the dispersing medium play a crucial role in gel formation. The self-assembly of pectin in solution occurs simultaneously with changes in its physicochemical properties. However, this process has not been described in detail to date. Therefore, the effect of pectin concentration on such properties as its surface electrical charge (Q), hydrogen ions binding (βH+) and total counterions binding (βtotal) during intermolecular interactions in different media was studied. Low–methoxyl diluted alkali–soluble pectin (DASP) extracted from pear fruits by using sodium carbonate was examined. Investigations were performed on a wide range of its content (1.84·10−4–1.84·100% w/v) in water and salt (NaCl and CaCl2) solutions with the ionic strength of 30 mM at 20 °C. Back Dynamic Light Scattering, Laser Doppler Electrophoresis, potentiometry and Atomic Force Microscopy methods were used. The DASP dissociation constant was calculated and used for determination of other physicochemical parameters. The relationship between changes in the physical and physicochemical properties of DASP during gelation was shown. An increase in the relative mean hydrodynamic diameter with DASP concentration was connected with the self–assembling (CaCl2) and cross–linking (water, NaCl) processes leading to gel formation. Simultaneously, the Q value decreased, βH+, βtotal and the contribution of βH+ to βtotal increased up to the obtained constant values at the gel state. Thus, the physicochemical properties of pectin may be indicators of the particular stages of macromolecules interactions occurring during gelation.

Reduced photosynthesis in Arabidopsis thaliana atpme17.2 and atpae11.1 mutants is associated to altered cell wall composition.

The cell wall is a complex and dynamic structure that determines plants' performance by constant remodeling of its compounds. Although cellulose is its major load-bearing component, pectins are crucial to determine wall characteristics. Changes in pectin physicochemical properties, due to pectin remodeling enzymes (PRE), induce the rearrangement of cell wall compounds, thus, modifying wall architecture. In this work, we tested for the first time how cell wall dynamics affect photosynthetic properties in Arabidopsis thaliana pectin methylesterase atpme17.2 and pectin acetylesterase atpae11.1 mutants in comparison to wild-type Col-0. Our results showed maintained PRE activities comparing mutants with wild-type and no significant differences in cellulose, but cell wall non-cellulosic neutral sugars contents changed. Particularly, the amount of galacturonic acid (GalA) - which represents to some extent the pectin cell wall proportion - was reduced in the two mutants. Additionally, physiological characterization revealed that mutants presented a decreased net CO2 assimilation (AN ) because of reductions in both stomatal (gs ) and mesophyll conductances (gm ). Thus, our results suggest that atpme17.2 and atpae11.1 cell wall modifications due to genetic alterations could play a significant role in determining photosynthesis.

Box\u2013Behnken design based statistical modeling for the extraction and physicochemical properties of pectin from sunflower heads and the comparison with commercial low-methoxyl pectin

A natural low-methoxyl pectin (LAHP), was extracted with oxalic acid solution from dried heads of sunflower (Helianthus annuus L.). The single-factor experiments and response surface methodology (RSM) were used to optimize LAHP extraction conditions. The extraction yield of LAHP was 18.83 ± 0.21%, and the uronic acid content was 85.43 ± 2.9% obtained under the optimized conditions (temperature of 96 °C, time of 1.64 h, oxalic acid concentration of 0.21%). Experimentally obtained values were in agreement with those predicted by RSM model, indicating suitability of the employed model and the success of RSM in optimizing the extraction conditions. LAHP has been characterized by ash content, degree of esterification (DE), galacturonic acid (GalA) content, molecular weight and intrinsic viscosity meanwhile commercial low-methoxyl pectin (CLMP) as comparison. This study finds out a potential source of natural LMP which expands the application scope of sunflower heads. It is an efficient reuse of waste resources and provides a novel thought to explore the natural resources for food and pharmaceutical applications.

Extraction Optimization and Physicochemical Properties of Pectin from Watermelon (Citrullus lanatus) Rind: Comparison of Hydrochloric and Citric acid Extraction

Extraction of pectin from watermelon (Citrullus lanatus) rind using citric acid, an organic acid was optimized using Response Surface Methodology (RSM) and compared to that using hydrochloric acid, a mineral acid. A five-level, four-factor central composite design was employed to optimize the conditions for maximum yield of pectin. The effects of pH, reaction temperature, reaction duration and substrate to extractant ratio were investigated. The optimized conditions using citric acid as an extractant were at pH 2, 80EÂA‚ÂsC, 3h and substrate to extractant ratio of 1:25. The optimized conditions using hydrochloric acid as an extractant were similar except for a shorter extraction time of 2h. At these extraction conditions, the yield of pectin extracted using citric acid (8.38 ± 0.43) was significantly higher than that using hydrochloric acid (6.52 ± 0.15) but showed similar uronic acid content (50.2-58.8%), degree of methylation (66.3-71.5%) and degree of acetylation (106.0-106.8%). Citric or hydrochloric acid-extracted watermelon rind pectin showed near Newtonian like flow behavior at 1% concentration and this behavior was similar to citrus peel pectin. This study demonstrated the use of citric acid as the more effective acid than hydrochloric acid to extract pectin and also the transformation of fruit waste to use material from watermelon rind.

Physicochemical properties of pectin from Malus domestica ‘Fălticeni’ apple pomace as affected by non-conventional extraction techniques

Six non-conventional techniques (microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction – with cellulase and Celluclast 1.5L, ultrasound-assisted extraction – heating treatment, and enzyme-assisted extraction – ultrasound treatment) and conventional citric acid extraction were applied to extract pectin from Malus domestica ‘Fălticeni’ apple pomace, and were compared in terms of extraction yields and physicochemical properties of the pectins. Microwave extraction led to the highest extraction yield and the lowest pectin recovery was found for the extraction with Celluclast 1.5L. Pectin samples obtained by microwave extraction showed color parameters comparable to commercial apple and citrus pectin, and had high galacturonic acid content, increased equivalent weight and high degree of esterification and molecular weight. High galacturonic acid content, molecular weight and degree of esterification were also found for pectin extracted by ultrasonication. On the opposite side, enzymatically extracted pectins had high equivalent weight, but lower degree of esterification that classified pectin extracted with cellulase as low-methoxylated pectin. Pectins obtained by ultrasound-assisted extraction – heating treatment and microwave extraction showed thermal properties that were similar to that of commercial pectins. The rheological characterization of pectin samples highlighted the high viscosities of solutions prepared with pectin from the ultrasound- and microwave-assisted extractions, which were correlated with their molecular weight and galacturonic acid content.

Effects of different microwave intensity on the extraction yield and physicochemical properties of pectin from dragon fruit (Hylocereus polyrhizus) peels

In this experiment, microwave-assisted extraction (MAE) was applied at different intensity of 300, 450, 600, and 800 W to extract pectin from dragon fruit peels. The microwave-assisted extraction was optimized using a central composite experimental design. The optimal extraction condition was established to be pH 2.07, extraction time of 65 s, and solid-to-liquid ratio of 66.57. The maxima extraction yields at 300, 450, 600, and 800 W were 11.8, 14.9, 17.2 and 18.5%, respectively. Experimental and predicted extraction yields obtained at the different microwave power levels were fitted to second-order response surface model. Microwave-assisted extraction process is effective in obtaining high-quality dragon fruit peel pectin, i.e. GalA content: 59.73–69.68%, DE value: 45.82–46.95%, crystallinity: 15.32–21.22%.

Temperature dependence of acid and calcium-induced low-methoxyl pectin gel extracted from Cyclea barbata Miers

The gel formation behaviour of green jelly leaf (GJL) pectins isolated by using water extraction method with extraction temperatures of 45, 65, 85 and 95 °C was investigated. The isolated pectins were also analysed for the yield, physicochemical and functional properties. The yield, molecular weight (Mw) and galacturonic acid content varied from ∼10 to 13% w/w, 3 × 105 to 12 × 105 g/mol and ∼75–86% w/w, respectively. Gelation of GJL pectins was a cold-setting gel and could be induced by acid and/or divalent ions; however, the latter gelation method showed a lesser temperature dependence than acid-induced gel. The addition of NaCl had enhanced the gel structure due to electrostatic screening effect. The mechanical spectra response showed that GJL pectin was typically gel-like with G′ greater than G″ and strongly influenced by pH and calcium concentration. The variation in pectin gel structures was also attributed to difference in pectin physicochemical properties particularly the degree of esterification (DE). Furthermore, lower DE pectins with higher charge values exhibited a stronger gel like properties with less variation on mechanical spectrum compared to higher DE pectins. These findings showed considerable potential of GJL pectin as a thickener and gelling agent and could be useful for development of low-sugar and high calcium content food with different textures.

Physicochemical properties of pectin from green jelly leaf (Cyclea barbata Miers)

The water extract of Green Jelly leaves (GJL) obtained by crushing the leaves in water (1:40) was capable of forming a gel at room temperature. The composition of GJL consisted mainly of carbohydrate (∼70w/w), protein (∼13% w/w) and minerals (∼6% w/w). The mineral portion consisted of mainly calcium (∼1.2% w/w), zinc (∼0.12% w/w) and magnesium (∼0.11% w/w). The isolated polysaccharide fraction (∼42.6% w/w) consisted of mainly galacturonic acid (∼35.8% w/w) and neutral sugars (∼6.8% w/w), with a weight-average molecular weight of ∼4.4×105g/mol. The results obtained by Fourier Transform Infra-Red (FTIR) showed that GJL polysaccharide fraction had a fairly similar FTIR fingerprint as the commercial low-methoxyl pectin (LMP). The degree of esterification of the polysaccharide changed drastically (from 97% to 10%) depending on the temperature used during the extraction process. The zeta potential of the extracted polysaccharide showed high negative charged as compared to the commercial LMP but close to sodium alginate. The study showed that the gelation was divalent cation-mediated and probably facilitated by the low degree of esterification which reduced steric hindrance from the methyl ester groups.