Water-extracted Pectin Research Articles

Valorization of pectic polysaccharides from Gardenia jasminoides Ellis flower: Physicochemical, structural, rheological, and functional properties

Gardenia jasminoides Ellis is a widely cultivated garden plant, but its flower resources are underutilized. In this study, three pectic polysaccharides extracted from Gardenia flowers (GFPPs) were obtained, including acid-extracted pectin (ACP), hot water-extracted pectin (HWP), and alkaline-extracted pectin (ALP). The physicochemical, structural, rheological, and functional properties of GFPPs were compared and analyzed. The results showed that the yield of all GFPPs exceeded 21%, and the proportion of the rhamnogalacturonan I (RG-I) regions ranged from 42.20% to 54.66%. The GFPPs were identified as low-methoxyl pectin with a semi-crystalline and amorphous structure. Among them, ACP had the highest molecular weight and neutral sugar content, while ALP had the highest content of galacturonic acid and protein. Rheologically, all three GFPPs exhibited pseudoplastic behavior with thixotropic properties, particularly ACP. Storage at low temperatures increased the apparent viscosity of ACP and HWP, while that of ALP was decreased. Importantly, emulsions prepared with 2% GFPPs and 10% medium-chain triglycerides remained stable at 4 °C and 25 °C for 21 days. Moreover, the ALP-based emulsion demonstrated excellent emulsifying capability, maintaining stability at 60 °C for 21 days with an emulsion appearance. These findings suggest that GFPPs hold promise as a pectin source for hydrocolloids and can be used in various food applications.

Physicochemical and functional properties of Lycium ruthenicum pectin by different extraction methods.

Three different extraction methods were used to extract high-temperature water-extracted pectin (HWp), high-temperature acid-extracted pectin (HAp), and high-temperature alkali-extracted pectin (HALp) from Lycium ruthenicum. The physicochemical properties, structure, and functional properties of three different pectins were studied. The results showed that HWp and HALp can extract rhamnogalacturonan-I (RG-I) from L. ruthenicum better. Through structural feature analysis, HWp and HALp have a branched structure, and HWp has a higher degree of esterification than HAp and HALp. Zeta potential results show that HWp solution is more stable. The thermal analysis results show that the thermal stability is HALp > HAp > HWp. HWp has the highest viscosity. The inhibitory activity results showed that HWp, HAp, and HALp have a certain inhibitory effect on α-glucosidase activity. This study shows the effects of different extraction methods on the properties of L. ruthenicum pectin and aims to provide a theoretical basis for the pharmaceutical and food industries to choose more suitable pectin extraction methods.

Composition and Characterization of Water Extractable Pectin from Pulp in Pods of Riang (Parkia timoriana (DC.) Merr.)

The purpose of this study was to preliminary investigate the extraction condition and composition of purified pectin from pulp in pods of Riang (Parkia timoriana (DC.) Merr.), a native tree in southern Thailand. Dry pulp of Riang was extracted using water or citric solvent at different concentrations under the same condition (90 ℃ for 2 h). It was found that the highest yield of pectin (21.6 % dry basis) was obtained by hot water extraction with an esterification degree of 48.3 %. It mainly contained 62.3 % galacturonic acid, followed by 18.5 % total sugar. The monosaccharides found in pectin were arabinose (2.6 %), galactose (2.3 %), glucose (1.5 %), mannose (0.5 %), fructose (0.5 %) and xylose (0.1 %). The finding pectin had a high average molecular weight of 2,070 KDa with a broad polydispersity index of 4.31, determined by high performance size exclusion chromatography (HPSEC) and it was classified as low methoxyl pectin confirmed by Fourier transform infrared spectroscopy (FT-IR) and rheological properties.
 HIGHLIGHTS
 
 Pectin from Riang pulp was low methoxyl pectin
 This pectin was water extractable and showed a high yield of 21.6 % (dry basis)
 It had high molecular weight with broad polydispersity index.
 
 GRAPHICAL ABSTRACT

Polysaccharides from sunflower stalk pith: Chemical, structural and functional characterization

Polysaccharides from sunflower stalk pith (SSP) were extracted by hot water and sodium hexametaphosphate (SHMP). Chemical analyses suggested both fractions dominated in galacturonic acids with a small amount of neutral sugars, indicating their identity as pectins. The weight average molecular weight and intrinsic viscosity for water-extractable pectin (WEP) and SHMP-extractable pectin (SEP) were 57.2 kDa, 0.48 dL/g and 23.1 kDa, 0.50 dL/g, respectively. The degree of esterification (DE) was calculated to be 92% and 64%, respectively. Methylation analysis demonstrated that 1,4-GalpA residues dominated all the sugar linkages, while other linkage types including 1,2-Rhap, 1,2,4-Rhap, 1,4-Galp and 1,5-Araf were also present in WEP and SEP. NMR spectroscopy further revealed WEP and SEP mainly demonstrated homogalacturonan (HG) structure and a small fraction of rhamnogalacturonan-I (RG-I) structure. The microstructure and water- and oil-holding capacity (WHC and OHC) of SSP was also examined. SSP was a microporous powder. Both WHC and OHC increased with particle size of the SSP, reaching up to over 40 g liquid/g fibre at particle size of 30 mesh (0.595 mm). However, the oil-SSP mixtures showed oil loss after absorption on filter paper for 24 or 48 h. Oil loss increased with SSP particle size decrease. 30 mesh SSP reduced oil loss in peanut butter by 74% with 2.2% addition.

Solubility Difference between Pectic Fractions from Creeping Fig Seeds.

Crude water-extracted pectin (WEP) isolated from creeping fig seeds were mainly fractionated into WEP-0.3 and WEP-0.4 fractions. Fractions were confirmed to be nonstarch, nonreducing sugars, nonpolyphenols and protein-unbounded acidic polysaccharides. Interestingly, a significant difference in solubility was found between WEP-0.3 (higher solubility than WEP) and WEP-0.4 (remarkably insoluble), which was consistent with the amorphous and porous sponge-like structure of WEP-0.3 as well as the crystalline and dense rod-like state of WEP-0.4. However, the result of the FT-IR spectra was contradicted by the solubility of WEP-0.4, which possessed the lowest degree of methoxylation and ought to possess the highest solubility. Through mineral analysis, a considerably high content of Ca2+ was found in WEP-0.4, suggesting that the low solubility of WEP-0.4 was probably attributable to the formation of microgels during dialysis. Therefore, metal divalent cations in the dialysate were suggested to be depleted for the dialysis of low methoxyl pectin.

Effects of maturity stages and solvent types on extraction yield and quality of Chu mango pulp pectin

Three different solvents including citric acid, hydrochloric acid and distilled water were studied on their capacity for extracting pectin from Chu mango pulp. In regard to the extraction solvent, hydrochloric acid showed the most efficient one for pectin extraction. The pectin amount extracted by hydrochloric acid (39.6±0.1 g 100 g-1 fresh weight (FW)) was significantly higher than those extracted by citric acid (37.0±0.8 g 100 g-1 FW) and distilled water (26.3±0.3 g 100 g-1 FW). WHC of the water-extracted pectin sample showed the highest value (7.2±0.9 g H2(O) g-1 dried pectin (DP)) among those were extracted using citric acid (4.9±0.2 g H2(O) g-1 DP) and hydrochloric acid (3.6±0.2 g H2(O) g-1 DP). Besides, FTIR spectrum has shown that all pectin samples extracted by these solvents can be classified into the high methoxyl pectin group that has the degree of esterification over 50%. Regardless of solvents, at three different maturities, the pectin yields collected were significantly different. The highest one was obtained at the 13th week after flowering (WAF) Chu mango pulp (66.9±2.1 g 100 g-1 FW), followed by those extracted at the 12th WAF Chu mango pulp (37.0±0.8 g 100 g-1 FW) and 11th WAF Chu mango pulp (28.0±0.8 g 100 g-1 FW). However, the highest water holding capacity were observed from pectin samples extracted at 11th WAF Chu mango pulp (5.8±0.5 g H2(O) g-1 DP), followed by 12th WAF (4.9±0.2 g H2(O) g-1 DP) Chu mango pulp and 13th WAF (3.4±0.1 g H2(O) g-1 DP) Chu mango pulp

Yield and structural composition of pomelo peel pectins extracted under acidic and alkaline conditions

Extraction of pectin from pomelo peel was performed using water, acid and alkaline solutions with a microwave power of 1100 W for 2 min, and yield and structural/chemical characteristics of the extracted pectins were investigated. Extraction of pectin with water gave the lowest yield (6.5%, dry weight basis). The water-extracted pectin contained the highest amount of neutral sugar (29.5%), while equivalent molecular weight (MWeq) and degree of methylation (DM) were 43 kDa and 29.7%, respectively. Extraction of pectin with HCl solutions at concentrations of 25, 50, 100 and 200 mM resulted in a significant increase of pectin yields (12.1–20.5%) and pectins with high amount of galacturonic acid (83.3–85.6%). The MWeq and DM of the acid-extracted pectins ranged from 171 to 368 kDa and 53.9–82.5%, respectively. Compared to the acid, extraction with NaOH solutions at the same concentrations provided higher yields (13.9–24.2%), smaller size (142–187 kDa) and lower DM (<1.7%) pectins, while amount of galacturonic acid was comparable. The highest yield of extraction was found at a concentration of 50 mM for both HCl and NaOH solutions. Extraction of pomelo peel with 50 mM NaOH solution by reduction of the microwave power to 550 W and extending the extraction time to 15 min resulted in an increase of pectin yield (29.2%) and pectin with smaller size (76 kDa).

Modification of Cell Wall Polysaccharides during Drying Process Affects Texture Properties of Apple Chips

The influences of hot air drying (AD), medium- and short-wave infrared drying (IR), instant controlled pressure drop drying (DIC), and vacuum freeze drying (FD) on cell wall polysaccharide modification were studied, and the relationship between the modifications and texture properties was analyzed. The results showed that the DIC treated apple chips exhibited the highest crispness (92) and excellent honeycomb-like structure among all the dried samples, whereas the FD dried apple chips had low crispness (10), the minimum hardness (17.4 N), and the highest volume ratio (0.76) and rehydration ratio (7.55). Remarkable decreases in the contents of total galacturonic acid and the amounts of water extractable pectin (WEP) were found in all the dried apple chips as compared with the fresh materials. The highest retention of WEP fraction (102.7 mg/g AIR) was observed in the FD dried apple chips, which may lead to a low structural rigidity and may be partially responsible for the lower hardness of the FD apple chips. In addition, the crispness of the apple chips obtained by DIC treatment, as well as AD and IR at 90°C, was higher than that of the samples obtained from the other drying processes, which might be due to the severe degradation of pectic polysaccharides, considering the results of the amounts of pectic fractions, the molar mass distribution, and concentrations of the WEP fractions. Overall, the data suggested that the modifications of pectic polysaccharides of apple chips, including the amount of the pectic fractions and their structural characteristics and the extent of degradation, significantly affect the texture of apple chips.

Mechanistic insight into common bean pectic polysaccharide changes during storage, soaking and thermal treatment in relation to the hard-to-cook defect

Different mechanisms responsible for the development of the hard-to-cook defect in common beans during storage, their soaking behavior and softening during thermal treatment have been previously suggested. However, these mechanisms have not been sufficiently confirmed by direct molecular evidence. This research aimed at gaining a detailed mechanistic insight into changes occurring in Canadian wonder bean pectic polysaccharides during storage, soaking and/or thermal treatment in different brine solutions in relation to the development and manifestation of the hard-to-cook (HTC) defect. Both fresh or easy-to-cook (ETC) and stored (HTC) bean samples were either soaked or soaked and thermally treated in demineralized water, solutions of Na2CO3 and CaCl2 salts followed by extraction of cell wall materials. Pectic polysaccharide properties examined included sugar composition, degree of methylesterification (DM), extractability and molar mass (MM). The DM of pectin from ETC and HTC beans was similar but low (<50%). Upon (pre)treatment in a Na2CO3 solution, solubilization of pectic polysaccharides, especially the strongly bound chelator- (CEP) and Na2CO3- (NEP) extractable pectins was enhanced leading to increased amounts of water extractable pectin (WEP). Also, there was a decrease in high MM polymers paralleled by an increase in β-elimination degradation products. These observations are in line with the fast cooking behavior of beans (pre)treated in a Na2CO3 solution. In contrast, (pre)treatment in a CaCl2 solution hindered softening leading to the failure of the beans to cook. The beans (pre)treated in a CaCl2 solution showed increased high MM polymers and lack of cell wall separation. Therefore, it can be inferred that development of the hard-to-cook defect in Canadian wonder beans during storage and its manifestation during soaking and subsequent thermal treatment is largely reflected by the pectic polysaccharide properties in line with the pectin hypothesis. Our data suggest the release of Ca++ leading to pectin cross-linking and the increase or decrease of β-elimination depolymerization. However, the relatively high amounts of neutral sugars and strongly bound NEP in HTC seeds do not allow to rule out the possible existence of non-Ca++ based pectin cross-linking.

Influence of high-pressure homogenization on functional properties of orange pulp

Abstract The current work evaluated whether high-pressure homogenization (HPH) could functionalize orange pulp in terms of water holding and swelling capacity and rheological properties. The orange pulp particle size was gradually decreased by applying HPH at increasing pressure (200 and 800 bar) whereby the mechanical impact at 800 bar resulted in the appearance of a more homogeneous, smoother suspension with a twofold increase in yield stress. HPH also affected the pectin properties within the orange pulp cell walls. More specifically, HPH at 800 bar increased the relative presence of water-extractable pectin. By investigating subsamples containing particles with different sizes isolated from orange pulp before and after HPH, it became clear that particle size is inversely related to water holding capacity and the ability of the particle network to deform prior to flow. Especially highly disintegrated orange pulp material ( Industrial relevance Orange pulp is of particular interest in the context of producing fiber-rich functional ingredients because of its large quantity available within the juice industry. High-pressure homogenization (HPH) at pressures higher than the ones usually applied in food industry seems required to functionalize orange pulp as HPH at 200 bar (a common pressure applied in the food industry) could not increase the relative presence of small particles, contributing to water holding capacity and soft particle network behavior, as substantially compared to HPH at 800 bar.

Extraction and characterisation of pomace pectin from gold kiwifruit (Actinidia chinensis)

Gold kiwifruit pomace extracted using citric acid, water and enzyme (Celluclast 1.5L) were studied in terms of pectin yield, protein, ash, non-starch polysaccharide, galacturonic acid (GalA), neutral sugar composition, molar mass (Mw), viscosity and degree of branching. Water-extracted pectin was considered closest to its native form. Enzyme extracted pectin showed the highest yield (∼4.5%w/w) as compared with the acid and water extraction methods (∼3.6–3.8%w/w). Pectin obtained from different extraction methods showed different degree of branching. The Mw and root mean square (RMS) radius varied with the extraction methods with values of 8.4×105g/mol and 92nm, 8.5×105g/mol and 102nm, 6.7×105g/mol and 52nm for acid, water and enzymatic extraction methods, respectively. Similar trend was observed for pectin viscosity, with water-extracted pectin giving a slightly higher viscosity followed by acid and enzyme-extracted pectin. This study showed that gold kiwifruit pomace pectin has potential application in food products.

Extraction, characterization and spontaneous gel-forming property of pectin from creeping fig (Ficus pumila Linn.) seeds

Creeping fig (Ficus pumila Linn.) seeds can be manually rubbed and squeezed to produce a water extract (WE) that can gel at room temperature without any additives. Its gelling material, extraction behavior, and mechanism of spontaneous gel-formation were investigated. Gelling material was extracted from seeds using water, ammonium oxalate and hydrochloric acid, respectively. Results showed the main component of three extracts is low methoxyl pectin. The pectin locates in a transparent layer on the surface of seeds, as revealed by an inverted microscope. Hence, explained the feasibility of the squeezing and rubbing method in traditional handcraft. Comparing with the other methods, water-extracted pectin has high galacturonic acid content, viscosity-average molecular weight and intrinsic viscosity but low degree of methoxylation. This pectin forms the major component of WE, together with the high amount of calcium ions present in WE, it suggests the spontaneous gelation may be based on the ‘egg-box’ formation.

Composition and properties of biologically active pectic polysaccharides from leek (Allium porrum)

Leek (Allium porrum) is very commonly used vegetable in Bulgaria and is distinctive with high content of bioactive components. Previously we obtained five crude pectic polysaccharides from leek through consecutive extraction. Some of them appeared to be good stimulators of the immune system. Schols and Voragen investigated the composition of modified hairy regions of pectic polysaccharides isolated from leek cell walls. Samuelson et al. identified the polysaccharide structures encountered in hairy regions as bioactive. The aim of this work was to study the isolation, composition and biological activities of pectic polysaccharides from leek. Two pectic polysaccharides from leek were isolated through consecutive water and acid extraction. The water extractable pectin had higher polyuronic content, higher protein content and lower neutral sugar content. It was found that next to galacturonic acid they also contain glucuronic acid in ratio 9:1 for the water- and 3:1 for the acid-extractable polysaccharide. The main neutral sugar was galactose. The water-extractable pectic polysaccharide had higher molecular weight (10(6) Da) and homogeneity. It was shown that the pectic polysaccharides from leek have considerable immunostimulating activities. Leek polysaccharides have relatively high galacturonic and glucuronic acid content and are distinguished with high biological activity.

Changes in the structure of apple pectic substances during ripening and storage

During ripening, the degree of polymerization, the degree of esterification, the neutral sugar content and the neutral sugar composition of extractable apple pectic substances did not change. Some xylose and glucose containing polysaccharides can be extracted from the ripe cell walls suggesting that changes in the hemicelluloses take place. In senescent apples, significant changes in the structure of apple pectic substances could be observed. The degree of polymerization of both the galacturonan chains and the arabinogalactan side chains decreased. The amount of water-extractable pectin molecules carrying 1,3/1,6-linked galactans increased. The degree of esterification and the distribution of the methoxyl groups in the apple pectic substances did not change very much.