Functional Properties Of Pectin Research Articles

Comparative Analysis of Physicochemical and Functional Properties of Pectin from Extracted Dragon Fruit Waste by Different Techniques.

Dragon fruit peel, often discarded, is a valuable source of commercial pectin. This study investigates different extraction methods, including cold-water (CW), hot-water (HW), ultrasound (US), and novel enzyme extraction (xylanase: EZX), to extract pectins from dragon fruit peel and compare their characteristics. The pectin yield ranged from 10.93% to 20.22%, with significant variations in physicochemical properties across methods (p < 0.05). FTIR analysis revealed that extraction methods did not alter the primary structural configuration of the pectins. However, molecular weights (Mws) varied significantly, from 0.84 to 1.21 × 103 kDa, and the degree of esterification varied from 46.82% to 51.79% (p < 0.05). Monosaccharide analysis identified both homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) pectic configurations in all pectins, predominantly comprising galacturonic acid (77.21-83.12 %mol) and rhamnose (8.11-9.51 %mol), alongside minor side-chain sugars. These properties significantly influenced pectin functionalities. In the aqueous state, a higher Mw impacted viscosity and emulsification performance, while a lower Mw enhanced antioxidant activities and promoted the prebiotic function of pectin (Lactis brevies growth). This study highlights the impact of extraction methods on dragon fruit peel pectin functionalities and their structure-function relationship, providing valuable insights into predicting dragon fruit peel's potential as a food-grade ingredient in various products.

Low methoxy feruloylated pectin from beetroot: Antioxidant and prebiotic properties

Pectin was extracted from beetroot pulp by acid hydrolysis using two concentrations of acid, 0.05 M and 0.1 M HCl and designated BRP1 and BRP2, respectively. CHNS, FTIR, and DSC analyses confirmed the purity and characterized it as a low methoxyl (LM) pectin. DPPH (%) inhibition was 22 and 11 for BRP1 and BRP2 and antioxidant activity determined by FRAP assay was 51 μM TE/g and 15 μM TE/g for BRP1 and BRP2, respectively. BR pectin significantly (p ≤ .05) stimulated the growth of Limosilactobacillus fermentum compared with citrus pectin. The highest prebiotic activity score (0.75) was observed for BRP1, followed by BRP2 (0.66), BR pulp (0.26), and citrus pectin (0.09). In addition, L. fermentum produced a higher amount of SCFA with BRP1 and BRP2 compared to the control. These results confirmed the bioactive and health-promoting potential of BR pectin and hence can be used as an effective bioactive ingredient for various functional foods. Novelty impact statement Extraction of low methoxy pectin was investigated using two different concentrations of acid. Structural and functional properties of pectin were influenced by acid extraction conditions. Both pectins contain feruloylated sugars that contribute to their antioxidant properties L. fermentum produced the highest amount of acetate with BRP1, whereas the highest amount of propionic acid and butyric acid was produced with BRP2.

Chemical, structural and functional properties of pectin from tomato pulp under different peeling methods

To protect tomato pulp quality, this study investigated the effect of the infrared peeling method (using our newly developed catalytic infrared peeling equipment) on pectin's chemical, structural and functional properties and their correlation compared with manual, hot-water, and lye peeling methods. Infrared peeling significantly improved pectin’s emulsifying and antioxidant capacity compared to manual peeling by increasing branching degree. Hot water peeling significantly improved pectin’s viscosity, emulsifying and antioxidant capacity. However, the pectin chains had low flexibility. The effect of lye peeling on pectin was the greatest, causing the lowest linearity and the largest degree of branching. In comparison, infrared peeling had the least impact on pectin. It was further confirmed that pectin’ viscosity, emulsifying, and antioxidant capacity were highly correlated with its chemical and structural properties. In summary, the infrared peeling method provides better pulp quality and is more sustainable because no water and chemicals are used.

Atmospheric pressure pin-to-plate cold plasma modification of high methoxyl apple pectin: Impact on functional properties

Modification of hydrocolloids by employing “green” processes such as cold plasma has gained attention in recent times. Apple pectin is a highly branched pectin, which leads to a low emulsification capacity. This study aims to understand the effect of cold plasma on the structural and functional properties of pectin, ranging from emulsification to antioxidant properties. In this study, atmospheric pressure cold plasma (230 V|3–15 min) was used for the modification of apple pectin (Degree of esterification (DE)∼68%). The viscosity-average-molecular weight decreased from 160677.4 to 98352.3 g mol −1 within 6 min of plasma treatment. A decrease in DE from 68 to 54% was observed after 15 min of treatment. An increase in galacturonic acid from 0.653 to 0.816 g g −1 and reducing sugars from 0.243 to 1.134% was noted after 15 min of treatment. The highest amount of unsaturated GalA residues (2.36 mmol/g) was formed after 12 min of treatment. The Ca 2+ sensitivity of the acid-sugar-pectin gels increased from 22.2 to 65.3 mPa s after 15 min of treatment. An increase in the whiteness index and a decrease in flow properties of the pectin powder were observed with the increasing duration of the treatment. This was well-evidenced in the Hausner's and Carr's indices, which increased from 1.23 to 1.48 and 0.24 to 0.35, respectively after 12 min of treatment. Prolonged treatments (>9min) negatively impacted emulsion stability. The DPPH radical scavenging activity and reducing power of pectin increased with the duration of plasma treatments for low concentrations of pectin (0.5–1.5%). The maximum DPPH radical scavenging activity (26.11%) was observed for 2% pectin dispersions, which were made from 12 min-plasma modified pectin. The future course of work can include the exploration of advanced applications of plasma-treated pectin in food matrices. • Cold plasma is a “green” method of pectin modification. • A decrease in degree of esterification and an increase in reducing sugars was observed. • Plasma modification decreased the viscosity and textural properties of pectin-sugar-acid gels. • An increase in emulsifying, foaming and antioxidant properties after the plasma treatment was identified.

Optimization of pectin extraction using response surface methodology: A bibliometric analysis

In this study, 209 articles have been surveyed on the “Pectin Extraction via Response Surface Methodology (RSM)” that have been collected from Web of Science© and Scopus©, and analyzed by using Bibliometrix, an RStudio package for science mapping analysis. Trends in the optimization and extraction methods of pectin via RSM have been pointed out, which may be useful for further research. Results shown that publications on “Pectin Extraction via RSM” have started for more than 20 years, with a growing trend, more than triplicating in the last 10 years. Based on such set of papers, China has been the most active country in local productions, whereas Iran, Brazil, India, and the United Kingdom have contributed with international-wide collaborative publications in optimization pectin extraction through RSM. Assisted extraction categories, physical and functional properties of pectin have taken on more relevance by 2012, especially with consolidation of microwave-assisted and ultrasound-assisted extraction techniques.

Effects of ultrasound, freeze-thaw pretreatments and drying methods on structure and functional properties of pectin during the processing of okra

Although, okra has features of high moisture content, rich nutrients, and pectin, it has extremely short shelf life, so deteriorate easily. Simple drying can prolong okra's shelf life but takes considerable time and is not cost-effective. Therefore, suitable pretreatments are usually employed to improve the drying efficiency and reduce the costs. This study showed that ultrasound (US) and freeze-thawing (FT) pretreatments, as well as three drying methods including vacuum pulsed drying (VPD), vacuum freeze-drying (VFD) and hot air drying (HD) have effects on structure and functional characteristics of okra pectin. The results indicated that drying methods affected differently the structure and chain conformation of the pectin molecular main chain. The thermal drying processes reduced molecular weight and increased viscosity, oxidation resistance, thermal stability, cohesion, and resilience. Particularly, the VPD pectin samples had lower molecular weight, higher antioxidant activity, better retention of the homogalacturonan (HG) main chain, thermal stability, emulsification activity, cohesiveness, resilience and weaker hardness and gel strength. The pretreatments had little effect on molecular weight, improved the antioxidant activity and emulsification activity of samples, and increased the viscosity of cold processed samples. US pretreatment retained pectin molecular chains, and FT pretreatment aggravated molecular chain debranching. In summary, VPD and US/FT pretreatments are beneficial to the development and utilization of pectin products.

Extraction temperature is a decisive factor for the properties of pectin

Pectin is an important food thickener and gelling agent and also, based on its bioactivities, is becoming viewed as a healthy polysaccharide. The functional properties of pectin are related to its structure which, if raw materials are similar, is controlled by extraction conditions. In our previous study we found that pectin recovered from citrus canning processing water showed some unique structural features and properties compared to commercial citrus pectin. Thus, the mechanism of pectin extraction under different conditions including the canning process, an unusual condition for pectin extraction, was studied. The same raw material of citrus fruit segment membrane was used and the properties of the extracted pectin and the resulting residue were characterized. The unusual low extraction temperature, applied in canning, was identified as a key factor for the unique structural features of the recovered pectin. The low-temperature extraction resulted in reduced yields (~9%, half of the commercial process), meanwhile, it limited the hydrolysis of pectin side-chains. The proportion of arabinose (Ara), one major side-chain sugar, was much higher (~23%), than that of commercial citrus pectin, resulting in a lower proportion of galacturonic acid (GalA). Moreover, the low-temperature extracted pectin having these structural features exhibited greater apparent viscosity and higher galectin-3 binding affinity (3.87 μM). The current study suggests the mechanism of pectin extraction and supplies important information for the extraction of functionally tailored pectin.

Transcription Factors BLH2 and BLH4 Regulate Demethylesterification of Homogalacturonan in Seed Mucilage.

The polysaccharide pectin is a major component of the plant cell wall. The pectic glycan homogalacturonan (HG) is a proportionally small but important component of a specialized seed cell wall called mucilage. HG is synthesized in a highly methylesterified form, and, following secretion, is de-methylesterified by pectin methylesterases (PMEs). The degree of methylesterification of HG determines the structural and functional properties of pectin, but how methylesterification is regulated remains largely unknown. Here, we identified two BEL1-Like homeodomain (BLH) transcription factors, BLH2 and BLH4, as positive regulators of HG de-methylesterification in Arabidopsis (Arabidopsis thaliana) seed coat mucilage. BLH2 and BLH4 were significantly expressed in mucilage secretory cells during seed mucilage production. BLH2 and BLH4 single mutants exhibited no obvious mucilage phenotype, but the blh2 blh4 double mutant displayed significantly reduced mucilage adherence to the seed. Reduced mucilage adherence in blh2 blh4 was caused by decreased PME activity in the seed coat, which increased the degree of methylesterification of HG in mucilage. The expression of several PME metabolism-related genes, including PME58, PECTIN METHYLESTERASE INHIBITOR6, SEEDSTICK, and MYB52 was significantly altered in blh2 blh4 seeds. BLH2 and BLH4 directly activated PME58 expression by binding to its TGACAGGT cis-element. Moreover, pme58 mutants exhibited reduced mucilage adherence similar to that of blh2 blh4, and the blh2 blh4 pme58 triple mutant exhibited no additional mucilage adherence defects. Furthermore, overexpression of PME58 in blh2 blh4 rescued the mucilage adherence defect. Together, these results demonstrate that BLH2 and BLH4 redundantly regulate de-methylesterification of HG in seed mucilage by directly activating PME58.

Pectin modification assisted by nitrogen glow discharge plasma

This study is concerned with modification of high methoxy pectin (HMP) assisted by nitrogen AC glow discharge plasma. Intrinsic viscosity of plasma treated pectin (PTP) was measured as primary index for structural changes in pectin molecules at different plasma conditions. The intrinsic viscosity of pectin increased within 7 min of exposure to plasma treatment and then remained constant. According to Fourier Transform Infrared Spectrometry (FT-IR) analysis, the intensity of carboxylate peaks increased in PTP samples due to de-esterification of pectin. Moreover, by decreasing the degree of esterification (DE) in PTP samples, the results of FT-IR were confirmed. Based on high performance size-exclusion chromatography (HPSEC) analysis, the molecular weight of PTP reduced. PTP gel had higher storage and loss modulus and shorter linear viscoelastic region. Moreover, X-ray diffraction (XRD) studies indicated an increase of crystallinity in PTP due to the formation of hydrogen bonds. Results revealed that nitrogen AC glow discharge plasma had significant influence on physicochemical and functional properties of pectin. The result of this study showed AC glow discharge plasma has promising potential towards modification of pectin.

Pistachio green hull pectin: Optimization of microwave-assisted extraction and evaluation of its physicochemical, structural and functional properties

The optimal microwave-assisted extraction conditions of pistachio green hull (PGH) pectin (extraction yield of 18.13%) were in microwave power of 700 W, irradiation time of 165 s, and pH of 1.5. The physico-chemical, structural and functional properties of pectin was examined and the results showed that PGH pectin under optimum conditions was low methoxyl (about 12.1%) with molecular weight of 1.659 kg/mol, emulsifying activity of 58.3%, total phenolic content of 18.18 mg GalAE/g pectin and good surface activity (46.23 and 49.75 mN/m at 0.1 and 0.5% w/v). Also, high performance liquid chromatography analysis illustrated that the pectin is including galacturonic acid (66.0%), arabinose (26.2%), galactose (3.7%), rhamnose (2.7%) and xylose (1.0%). In addition, 1H NMR and FTIR spectrums confirmed the presence of pectin in obtained supenatnt. Surface morphology analysis and X-ray diffraction pattern showed that PGH pectin had a rough surface with crystalline structure.

The effect of heat processing on the functional properties of pectin contained in olive mill wastewater

The purpose of this study was to evaluate the effect of prolonged heat processing (180 min at 50–80 °C) on the functional and rheological properties of pectin, derived from olive mill wastewater (OMW). It was shown that a low temperature blanching of OMW at 60 °C, activates endogenous pectin methyl esterase and promotes demethylation, despite the high concentration of phenols. Activation of the enzyme resulted in enhanced solubilization and subsequent partial degradation of pectin. The induced degradation impaired pectin grade and resulted in loss of gelling functionality. An alternative heating process at 80 °C resulted in negligible enzyme induced degradation of the pectin and improved gelling properties of the recovered material, despite the lower solubilization of the pectin. The obtained results contribute to a better understanding of the temperature effect on pectin functional properties and can be utilized in order to optimize pectin recovery from OMW.

Nonesterified galacturonic acid sequence homology of pectins.

The methyl ester distribution of pectins was studied with a recently developed enzymatic method. Endopolygalacturonase of Kluyveromyces fragilis was used to degrade pectin and the composition of the degradation products was determined with high-performance anion-exchange chromatography at pH 5. Three characteristics indicative for the distribution of nonesterified galacturonic acid residues were obtained: the percentage of nonesterified galacturonic acid residues liberated of the total number of nonesterified galacturonic acid in the undigested polymer, the proportion of nonesterified mono-, di-, and trigalacturonic acid released, and the ratio of the sum of the peak areas of methyl ester containing oligomers divided by the sum of the peak areas of the nonesterified oligomers detected. From these characteristics and the degree of methyl esterification, the mean sequence similarity of the methyl ester distributions was calculated. Computational techniques commonly employed in the determination of the sequence similarity of DNA and proteins were used to discriminate the various types of distributions found and to construct a distance tree. In general, three types of methyl ester distributions could be discerned in pectin: random, high, and blockwise esterified. This report is the first to describe a parametric approach for the comparison of the substituent distribution in polymers. The importance of this novel approach in the study of the methyl ester distribution and the functional properties of pectin is discussed.

Study of the methyl ester distribution in pectin withendo-polygalacturonase and high-performance size-exclusion chromatography

A method was developed that enables the study of the methyl ester distribution in the polymers of pectin on a molecular level. Endo-polygalacturonase was used to extensively degrade three 70% methyl esterified pectins. The molecular weight distribution of the non- and enzymatically degraded pectins was determined with high-performance size-exclusion chromatography. Next, the molecular weight distribution was converted into a degree of polymerization distribution of galacturonan fragments. Monte Carlo methods were employed for the reconstruction of the parental polymers from their enzymatic degradation products. The results for the random methyl esterified pectin revealed that the enzyme-degradable sites were indeed randomly distributed, which confirmed the correctness of the procedure developed. The two other pectins studied differed greatly in the amount of non-, low-, and high-esterified regions present in the reconstructed pectic molecules of a given molecular mass. That the approach developed is able to reveal such detailed information makes it unique. The information on the fragmental composition of pectic polymers obtained is an important addition to the study of the methyl ester distribution and the functional properties of pectin.