Pectin Structure Research Articles

Enzymatic Hydrolysis Modifies Emulsifying Properties of Okra Pectin.

Okra pectins (OKPs) with diverse structures obtained by different extraction protocols have been used to study the relationship between their molecular structure and emulsifying properties. A targeted modification of molecular structure offers a more rigorous method for investigating the emulsifying properties of pectins. In this study, three glycoside hydrolases, polygalacturonase (PG), galactanase (GL), and arabinanase (AR), and their combinations, were used to modify the backbone and side-chains of OKP, and the relationships between the pectin structure and emulsion characteristics were examined by multivariate analysis. Enzymatic treatment significantly changed the molecular structure of OKP, as indicated by monosaccharide composition, molecular weight, and structure analysis. GL- and AR- treatments reduced side-chains, while PG-treatment increased side-chain compositions in pectin structure. We compared the performance of hydrolyzed pectins in stabilizing emulsions containing 50% v/v oil-phase and 0.25% w/v pectin. While the emulsions were stabilized by PG (93.3% stability), the emulsion stability was reduced in GL (62.5%), PG+GL+AR (37.0%), and GL+AR (34.0%) after 15-day storage. Furthermore, microscopic observation of the droplets revealed that emulsion destabilization was caused by flocculation and coalescence. Principal component analysis confirmed that neutral sugar side-chains are key for long-term emulsion stabilization and that their structure explains the emulsifying properties of OKP. Our data provide structure-function information applicable to the tailored extraction of OKP with good emulsification performance, which can be used as a natural emulsifier.

Structure and bioactivity of apple pectin isolated with arabinanase and mannanase

It was assumed that, high purity endo-arabinanase and endo-mannanase could be useful in the isolation of pectin of enhanced health-promoting potential. Extraction was carried out with 50 U of enzymes per gram of apple pomace at 40 °C, obtaining up to 22% increase in effectiveness, as compared to the acid extraction. The pectins, despite their high Mw, were homogeneous and contained more galacturonic acid, rhamnose, galactose, fucose, and ferulic acid than the conventional product, thanks to which they quenched free radicals up to five times more efficiently. Compared with pectin with recognised anticancer and prebiotic activity, they had a significantly greater ability to inhibit proliferation and migration of HT-29 and B16F10 cells. They were also more effective in preventing the adhesion of E. coli and S. typhimurium to enterocytes. Endo-arabinanase- and endo-mannanase-assisted extraction is an effective method of obtaining pectins with enhanced antiradical, anticancer and prebiotic potential.

Conventional and Emerging Novel Techniques for the Extraction of Pectin and Applications of Pectin

Agricultural crops and its by-product utilization is an emerging area in Food Industry. The waste generated from processing industries is generally disposed off, ultimately hampering the environment. However, this waste is a rich source of many valuable components, pectin being one of them. Pectin, a heteropolysaccharide has numerous nutritional and functional properties making its extraction a matter of utmost importance. Although it is present in cell wall of most of the plants but its amount, structure and chemical composition differs between plants and makes its recovery tedious. In order to commercialize, yield and quality of pectin are important parameters to be considered during extraction. Therefore, selection of a convenient technique is essential. However, conventional extraction method is being widely used; it has some limitations such as laborious handling and certain environmental concerns. Therefore, there is a need to exploit novel pectin extraction techniques. In addition to that, there are many other parameters (increase in cost and skilled labor) to be considered in order to have clear insight of the possibilities to scale up the process. The present review discusses the chemical structure and classification of pectin, its properties and source of recovery with primary focus on innovative pectin extraction techniques.

PpePL1 and PpePL15 Are the Core Members of the Pectate Lyase Gene Family Involved in Peach Fruit Ripening and Softening.

Pectin is the major component in the primary cell wall and middle lamella, maintaining the physical stability and mechanical strength of the cell wall. Pectate lyase (PL), a cell wall modification enzyme, has a major influence on the structure of pectin. However, little information and no comprehensive analysis is available on the PL gene family in peach (Prunus persica L. Batsch). In this study, 20 PpePL genes were identified in peach. We characterized their physicochemical characteristics, sequence alignments, chromosomal locations, and gene structures. The PpePL family members were classified into five groups based on their phylogenetic relationships. Among those, PpePL1, 9, 10, 15, and 18 had the higher expression abundance in ripe fruit, and PpePL1, 15, and 18 were upregulated during storage. Detailed RT-qPCR analysis revealed that PpePL1 and PpePL15 were responsive to ETH treatment (1 g L−1 ethephon) with an abundant transcript accumulation, which suggested these genes were involved in peach ripening and softening. In addition, virus-induced gene silencing (VIGS) technology was used to identify the roles of PpePL1 and PpePL15. Compared to controls, the RNAi fruit maintained greater firmness in the early storage stage, increased acid-soluble pectin (ASP), and reduced water-soluble pectin (WSP). Moreover, transmission electron microscopy (TEM) showed that cell wall degradation was reduced in the fruit of RNAi-1 and RNAi-15, which indicated that softening of the RNAi fruit has been delayed. Our results indicated that PpePL1 and PpePL15 play an important role in peach softening by depolymerizing pectin and degrading cell wall.

Phenotyping of a diverse tomato collection for postharvest shelf-life

In all fruit and vegetable crops, reduction in quality during postharvest storage leads to substantial losses of primary production with enormous economic consequences. Also in tomato, fruit shelf-life is an important quality trait. In this study a collection of tomato accessions, consisting of 92 S. lycopersicum landraces and old cultivars and several S. pimpinellifolium accessions, was phenotyped for several shelf-life parameters and biochemical characterization was performed during the postharvest shelf-life of fruit from selected accessions. This collection was selected based on available genotypic data and represents the genetic diversity present in the EU–SOL tomato core collection (Roohanitaziani, 2020). The core collection was grown in a greenhouse, and fruit were harvested at the breaker-turning stage and stored in a controlled climate chamber for 42 d at 18 ⁰C. The shelf-life attributes firmness loss, weight loss, as well as color pigments, were measured once a week and evaluated over time. All three shelf-life-related parameters varied markedly among accessions, resulting in fruit with different shelf-life. The most promising accessions of the first screen were re-grown and analyzed to validate the initial results and six accessions with contrasting shelf-life were selected for metabolite analysis. Fruit were harvested at the breaker stage and stored for 35 d at 18 ⁰C. Samples were taken at weekly intervals and analyzed for volatile compounds, primary metabolites and cell wall polysaccharide monomers. During storage long and short shelf-life accessions showed considerable differences in their content of sugars, such as galactose and polyamines, such as putrescine in their pericarp. The content of three cell wall sugars, galactose, arabinose and galacturonic acid, underwent considerable changes during postharvest storage. The short shelf-life accessions contained a higher amount of arabinose and galactose in their cell wall than other accessions which is indicative of highly branched pectin. This knowledge provides a better understanding of the difference in pectin structure between short and long shelf-life fruit during the ripening process.

Production of mucic acid from pectin-derived D-galacturonic acid: a review

Mucic acid is a hexaric acid that can be biosynthesized by oxidation of D-galacturonic acid, which is the main constituent of pectin. The structure and properties of mucic acid are similar to that of glucaric acid, and can be widely applied in the preparation of important platform compounds, polymers and macromolecular materials. Pectin is a cheap and abundant renewable biomass resource, thus developing a process enabling production of mucic acid from pectin would be of important economic value and environmental significance. This review summarized the structure and hydrolysis of pectin, the catabolism and regulation of D-galacturonic acid in microorganisms, and the strategy for mucic acid production based on engineering of corresponding pathways. The future application of mucic acid are prospected, and future directions for the preparation of mucic acid by biological method are also proposed.

Enzyme-extracted raspberry pectin exhibits a high-branched structure and enhanced anti-inflammatory properties than hot acid-extracted pectin

To characterize the structure of purified raspberry pectin and discuss the impact of different extraction methods on the pectin structure, raspberry pectin was extracted by hot-acid and enzyme method and purified by stepwise ethanol precipitation and ion-exchange chromatography isolation. Enzyme-extracted raspberry pectin (RPE50%-3) presented relatively intact structure with molecular weight of 5 × 104 g/mol and the degree of methylation was 39%. The 1D/2D NMR analysis demonstrated RPE50%-3 was a high-branched pectin mainly containing 50% homogalacturonan, 16% branched α-1,5-arabinan and α-1,3-arabinan, 18% β-1,4-galactan and β-1,6-galactan. Acid-extracted raspberry pectin (RPA50%-3) contained less arabinan than RPE50%-3. Moreover, RPE50%-3 inhibited the nitric oxide (NO), TNF-α, IL-6 production of lipopolysaccharide-induced macrophages by 67%, 22% and 46% at the dosage of 200 ug/mL, while the inhibitory rate of RPA50%-3 were 33%, 9%, and 1%, respectively. These results suggested that enzyme-extracted raspberry pectin contained more arabinan sidechains and exhibited better immunomodulatory effect.

Effect of Ultrasound-Assisted, Microwave-Assisted and Ultrasound-Microwave-Assisted Extraction on Pectin Extraction from Industrial Tomato Waste

This work aimed to study the effect of ultrasound-assisted (UAE), microwave-assisted (MAE), and ultrasound-microwave-assisted (UMAE) methods for pectin extraction from industrial tomato waste. The overall performance index from the fuzzy analytical method with three criteria, pectin yield, galacturonic acid, and lycopene content, was applied to evaluate the best extraction conditions by using the weight of 75, 20, and 5, respectively. The UAE conditions was performed at a temperature of 80 °C for 20 min with the variations in the extraction pH and the solid liquid (SL) ratio. The best UAE conditions with high pectin yield, and high total carboxyl group, as well as a lycopene content, was the pH of 1.5 and the SL ratio of 1:30. The MAE conditions was performed with variations in the microwave powers and times. The results showed that the best MAE conditions were 300 W for 10 min, which gave high pectin yield with high galacturonic acid and lycopene content. Various conditions of UMAE at the best conditions of MAE and UAE were performed and exhibited that the UAE had more positively affected the pectin yield. However, the FTIR spectra of obtained pectins from different extraction techniques showed a similar pectin structure.

Effects of enzymatic treatment on the physicochemical properties and antioxidant activity of hawthorn pectin

The effects of enzymatic treatment on the physicochemical properties and antioxidant activity of natural hawthorn pectin (CK) were evaluated using a series of characterization methods. The results indicated that four modified pectin preparations (MPE, MPLE, MPME, and MCE, respectively obtained through treatment with pectinase, pectin lyase, pectin methylesterase, and cellulase) all showed a low methoxy content. MPLE had the highest galacturonic acid (Gal A, 92.01%) content and the highest degradation temperature (135 ℃). MPME had the lowest molecular weight (3.59 kDa) and MCE had the smallest particle size (238.0 nm). Infrared spectroscopy (FTIR) indicated that the enzymatic treatment did not change the primary structure of pectin. Scanning electron micrographs (SEM) showed that the four modified pectin preparations were more fragmented and irregular. Antioxidant activity of the pectin preparations was evaluated by determining their radical scavenging ability (hydroxyl radical and ABTS radical) and reducing power. The IC50 for hydroxyl radical and ABTS radical of all modified pectin preparations was lower than CK. The reducing power of MPE and MPME was higher than that of CK. Different enzymes modification methods played an important role on the characterization of pectin. Enzymatic modification methods offer great promise for the application of hawthorn pectin in functional products.

A Gluten‐Free Biscuit Fortified with Lemon IntegroPectin

AbstractWe report the first outcomes of producing a gluten‐free biscuit by replacing 2.5 wt% of the rice flour used in the preparation of a commercial gluten‐free cookie with lemon IntegroPectin, a new citrus pectin obtained from lemon processing waste via hydrodynamic cavitation. The cookie's friability, palate adhesion, flavor persistency and compactness remain virtually unchanged, whereas sapidity and color improve. Only the sweetness and the smell (flavor) of the functionalized cookie are lower than those of the commercial biscuit. The enhanced heat resistance and unique structure of this new citrus pectin unveiled by XRD and TGA structural and thermal analyses make it suitable for the straightforward functionalization of bakery products with numerous potential health benefits.

Changes of pectin structure and microbial community composition in strawberry fruit (Fragaria × ananassa Duch.) during cold storage

Strawberry is very perishable fruit with rapid postharvest loss of quality and high susceptibility to microbial infections. In this work we study pectin modifications and microbiota and mycobiota composition in strawberry in conventional and organic cultivation systems. The enzymatic activity during postharvest storage of both types of strawberry was divided at the fifth day of storage into two phases: postharvest changes and rotting. Pectin molecules extracted from organic strawberries were longer and more branched compared to the conventional strawberries; however a more noticeable reorganization of molecular structure occurred. The sequential action of the pectinolytic enzymes had a direct effect on the molecular structure of pectin fractions. The observed changes in pectin structure relate to the synergistic activity of pectinolytic enzymes and some microorganisms. The organic system was characterized by a greater number and variety of bacteria and fungi during storage as compared to the conventional system.

Biochemical Characterization of Two Rhamnogalacturonan Lyases From Bacteroides ovatus ATCC 8483 With Preference for RG-I Substrates.

Rhamnogalacturonan lyase (RGL) cleaves backbone α-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acid residues in type I rhamnogalacturonan (RG-I) by β-elimination to generate RG oligosaccharides with various degrees of polymerization. Here, we cloned, expressed, purified and biochemically characterized two RGLs (Bo3128 and Bo4416) in the PL11 family from Bacteroides ovatus ATCC 8483. Bo3128 and Bo4416 displayed maximal activity at pH 9.5 and pH 6.5, respectively. Whereas the activity of Bo3128 could be increased 1.5 fold in the presence of 5 mM Ca2+, Bo4416 required divalent metal ions to show any enzymatic activity. Both of RGLs showed a substrate preference for RG-I compared to other pectin domains. Bo4416 and Bo3128 primarily yielded unsaturated RG oligosaccharides, with Bo3128 also producing them with short side chains, with yields of 32.4 and 62.4%, respectively. Characterization of both RGLs contribute to the preparation of rhamnogalacturonan oligosaccharides, as well as for the analysis of the fine structure of RG-I pectins.

Kinetics of structural change of pineapple (Ananas comosus) under the influence of PME (Pectin methylesterase)

The structure of pineapple ((Ananas comosus) is hard and brittle, but it is easy to soften under the influence of high temperature during processing. Understanding the structure, arrangement and chemical reactivity of pectin in the cell wall is key to predicting and controlling changes in cluster structure. There are many different methods to affect the pectin composition to create an insoluble calcium pectate complex to keep the connection between cells, keep the structure for pineapple. The addition of the pectin methylesterase enzyme (PME) extracted from tomato to pineapple is one of the recent researched trends with the aim of improving the structural change of pineapple due to heat. Based on the recommendations made from previous studies on enzyme addition to pineapple, in this study, experiments were conducted on the influence of the order of addition of PME and CaCl2, the effect of temperature of PME addition, and the influence of PME activity on the structural change of pineapple.

Alteration of pectin metabolism in blood orange fruit (Citrus sinensis cv. Tarocco) in response to vesicle collapse

Abstract Segment drying is a severe physiological disorder of citrus fruit, and vesicles become granulated or collapsed. Aside from the hypothesis that alteration of cell wall metabolism is the main factor of citrus granulation, little is known about vesicle collapse. This study aimed to elucidate the changes in pectin metabolism during vesicle collapse in blood orange. Vesicle collapse was characterized by decreased nutrients and increased chelate- and sodium carbonate-soluble pectin and calcium content. The nanostructure of chelate-soluble pectin became complex and developed multi-branching upon collapse. The activity of pectin methylesterase increased, while that of polygalacturonase and pectate lyase decreased upon collapse. Genome-wide transcriptional analysis revealed an increasing pattern of genes encoding pectin methylesterase and other enzymes involved in pectin synthesis and demethylesterification upon collapse. Drying vesicles were characterized by increased abscisic acid content and relevant gene expression. In conclusion, we discovered alteration in pectin metabolism underlying citrus vesicle collapse, mainly promoting pectin demethylesterification, remodeling pectin structures, and further inhibiting pectin degradation, which was hypothesized to be a main factor for citrus collapse. This is the first study to disclose the potential intrinsic mechanism underlying vesicle collapse in orange fruit.

The The Effect of Concentration of Citric Acid Solution on Extraction of Pectin from Watermelon Albedo

Watermelon albedo or the white flesh of watermelon rind contains pectin with high enough content. In this study was conducted the extraction of pectin from watermelon albedo by the liquid-solid extraction method. The citric acid solution was used as a solvent with concentrations varied by 4%, 7%, and 10%. The research steps include the pretreatment of raw material, the extraction, the posttreatment of extraction, and the analysis of pectin. The pretreatment aimed to reduce water content and reduce the size of raw material. The extraction process was the main process in which pectin dissolution occurred in the citric acid solvent. Furthermore, the posttreatment of extraction aimed to obtain pectin solid with the addition of ethanol. The final step was the analysis, including pectin yield, moisture content, methoxyl content, galacturonic acid content, and pectin functional group. Based on research obtained, an increase in the concentration of citric acid increased pectin yield, methoxyl content, and galacturonic acid content. The moisture content of pectin decreased with the increasing concentration of citric acid. Pectin yield, moisture content, methoxyl content, galacturonic acid content resulted from 10% concentration of citric acid solvent are 8.356%, 19.748%, 7.029%, and 69.048%, respectively. Based on FTIR analysis, the functional groups contained in pectin are hydroxyl group, methyl group, carbonyl group, and ether group. This functional groups are main constituents of pectin structure.

Does the Food Ingredient Pectin Provide a Risk for Patients Allergic to Non-Specific Lipid-Transfer Proteins?

Pectin, a dietary fiber, is a polysaccharide that is widely used in food industry as a gelling agent. In addition, prebiotic and beneficial immunomodulatory effects of pectin have been demonstrated, leading to increased importance as food supplement. However, as cases of anaphylactic reactions after consumption of pectin-supplemented foods have been reported, the present study aims to evaluate the allergy risk of pectin. This is of particular importance since most of the pectin used in the food industry is extracted from citrus or apple pomace. Both contain several allergens such as non-specific lipid transfer proteins (nsLTPs), known to induce severe allergic reactions, which could impair the use of pectins in nsLTP allergic patients. Therefore, the present study for the first time was performed to analyze residual nsLTP content in two commercial pectins using different detection methods. Results showed the analytical sensitivity was diminished by the pectin structure. Finally, spiking of pectin with allergenic peach nsLTP Pru p 3 led to the conclusion that the potential residual allergen content in both pectins is below the threshold to induce anaphylactic reactions in nsLTP-allergic patients. This data suggests that consumption of the investigated commercial pectin products provides no risk for inducing severe reactions in nsLTP-allergic patients.

New insights in pectinase production development and industrial applications.

Pectinase, a group of pectin degrading enzymes, is one of the most influential industrial enzymes, helpful in producing a wide variety of products with good qualities. These enzymes are biocatalysts and are highly specific, non-toxic, sustainable, and eco-friendly. Consequently, both pectin and pectinase are crucially essential biomolecules with extensive applicatory perception in the biotechnological sector. The market demand and application of pectinases in new sectors are continuously increasing. However, due to the high cost of the substrate used for the growth of microbes, the production of pectinase using microorganisms is limited. Therefore, low-cost or no-cost substrates, such as various agricultural biomasses, are emphasized in producing pectinases. The importance and implications of pectinases are rising in diverse areas, including bioethanol production, extraction of DNA, and protoplast isolation from a plant. Therefore, this review briefly describes the structure of pectin, types and source of pectinases, substrates and strategies used for pectinases production, and emphasizes diverse potential applications of pectinases. The review also has included a list of pectinases producing microbes and alternative substrates for commercial production of pectinase applicable in pectinase-based industrial technology.Key points• Pectinase applications are continuously expanding.• Organic wastes can be used as low-cost sources of pectin.• Utilization of wastes helps to reduce pollution.

Emerging trends on the role of recombinant pectinolytic enzymes in industries- an overview

The primary energy requirement of almost all life-forms on earth is derived from plant sources. The plant cell wall (PCW) has a chemically complex structure composed of glycoproteins, aromatic compounds and carbohydrates. The carbohydrates include cellulose, hemicellulose and pectin. Cellulose has homogeneous structure, whereas hemicellulose and pectin are heterogeneous. Pectin constitutes as the most complex polysaccharide and is abundantly found in the middle lamella and primary cell wall of PCW. It is also proportionally the highest constituent of plant dry matter. The pectic substances are hydrolyzed by pectinolytic enzymes which are widely present in bacteria, fungi and plants. Pectinolytic enzymes are classified as de-polymerising and de-esterifying enzymes. The de-esterifying enzymes are the accessory enzymes which remove the side chains. The pre-action of de-esterifying enzymes removes the steric hindrance and provides better access to other de-polymerizing enzymes for complete degradation of pectin. This review describes the pectin structure and the structure, function and biochemical properties of recombinant pectinolytic enzymes from different microbial sources. The focus is on the specific role of individual pectinolytic enzymes in various industrial applications such as juice extraction, vegetable puree production, fibre retting, waste water treatment, pharmaceuticals, biomass hydrolysis and production of other value-added products. Thus, the enhanced use of pectinolytic enzymes in these growing industries holds a great potential for gaining insights about their efficient role in various sectors. • A core information about pectin structure and its components has been incorporated. • It details the structure, function and mode of action of individual pectinases. • Recent developments in novel bioengineered pectinolytic enzymes are included. • It elaborates recent advances on the role of individual pectinases in industries.

High throughput in vitro characterization of pectins for pig(let) nutrition

BackgroundFiber-rich feed components possess prebiotic potential to enhance pig health and are considered a potential solution to the high prevalence of post-weaning diarrhea in pig production under the phased suspension of antibiotics and zinc oxide use.MethodsWe screened the gut microbiota modulatory properties of pectin substrates prepared from sugar beet within the freshly weaned piglet gut microbiome using an in vitro colon model, the CoMiniGut. We focused on testing a variety (13) of sugar beet-derived pectin substrates with defined structures, as well as known prebiotics such as inulin, fructooligosaccharide (FOS) and galactooligosaccharide (GOS), to gain insights on the structure–function related properties of specific substrates on the weaner gut microbial composition as well as shortchain fatty acid production (SCFA).ResultsSugar beet-derived pectin and rhamnogalacturonan-I selectively increased the relative abundance of Bacteroidetes, specifically Prevotella copri, Bacteroides ovatus, Bacteroides acidificiens, and an unclassified Bacteroides member. The degree of esterification impacted the relative abundance of these species and the SCFA production during the in vitro fermentations. Modified arabinans derived from sugar beet promoted the growth of Blautia, P. copri, Lachnospiraceae members and Limosilactobacillus mucosae and amongst all oligosaccharides tested yielded the highest amount of total SCFA produced after 24 h of fermentation. Sugar beet-derived substrates yielded higher total SCFA concentrations (especially acetic and propionic acid) relative to the known prebiotics inulin, FOS and GOS.ConclusionOur results indicate that the molecular structures of pectin, that can be prepared form just one plant source (sugar beet) can selectively stimulate different GM members, highlighting the potential of utilizing pectin substrates as targeted GM modulatory ingredients.

Flavonoids in Lemon and Grapefruit IntegroPectin*.

Following the analysis of terpenes present in new lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, the HPLC‐MS analysis of flavonoid and other phenolic compounds reveals the presence of eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits. The pectic fibers rich in rhamnogalacturonan‐I regions act as chemical sponges adsorbing and concentrating at their outer surface highly bioactive citrus flavonoids and terpenes. These findings, together with the unique molecular structure of these new whole citrus pectins, provide preliminary insight into the broad‐scope biological activity of these new biomaterials. Numerous new biomedical applications are anticipated, including likely use in the prevention and treatment of microbial infections and neurodegenerative disease.