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Polysaccharide constituents including water-soluble polysaccharides, pectic substances, and hemicelluloses were isolated from Datura stramonium L. (Solanaceae) leaves. Their monosaccharide compositions were established. The monomer compositions of the isolated biopolymers included neutral and acidic monosaccharides. Prebiotic activity was found for the water-soluble polysaccharides isolated by cold water. [ABSTRACT FROM AUTHOR]

Pectic substances cause haziness and high viscosity of fruit juices. Pectinase enzymes are biological compounds that degrade pectic compounds. Nontoxicity and ecofriendly nature make pectinases excellent biocatalysts for juice clarification. However, the poor stability and nonreusability of pectinases trim down the effectiveness of the operation. The immobilization techniques have gained the attention of researchers as it augments the properties of the enzymes. Literature has reported the stability improvement of enzymes like lipase, laccase, hydrogen peroxidase, and cellulase upon immobilization on the membrane. However, only a few research articles divulge pectinase immobilization using a membrane. The catalysis‐separation synergy of membrane‐reactor has put indelible imprints in industrial applications. Immobilization of pectinase on the membrane can enhance its performance in juice processing. This review delineates the importance of physicochemical and kinematic properties of pectinases relating to the juice processing parameters. It also includes the influence of metal‐ion cofactors on enzymes' activity. Considering the support and catalytic‐separation facets of the membrane, the prediction of the membrane as support for pectinase immobilization has also been carried out. [ABSTRACT FROM AUTHOR]

Today, the healthy nutrition market is one of the most promising market niches; modern consumers increasingly claim fortified products for their diets. One of the ways to increase the biological and physiological value of products is their enrichment with extracts of plant origin. The aim of the work was to study the influence of various factors on the process of hawthorn fruit extraction and determine the optimal parameters of the technological process. The study objects were hawthorn fruit extracts produced by the statistical method of maceration (with stirring). In the extracts obtained, there were determined the quantitative content of tannins and pectin substances, dietary fiber and vitamins. Currently, the global health and wellness food market is steadily growing due to changes in consumer behaviour patterns and developing of healthy self-consciousness. The studies conducted by the authors have shown that extracting of plant materials and the efficiency of biologically active substances extraction are influenced by the following factors: the extractant pH, grinding type and size of raw materials and process parameters. The optimal technological regimes have been established. They are the extraction temperature of 60 °C and extraction time of 30 minutes. The appropriate grinding size of dry hawthorn fruit has been determined to be up to 2.8 mm of a particle. In case of milk being an extractant, a high extraction dynamic of pectic substances and dietary fibers was observed. So, the hawthorn milk extract has been revealed to have higher organoleptic characteristics.

Both pectin and pectinase are vitally imperative biomolecules in the biotechnological sector. These molecules are a feasible non-toxic contrivance of nature with extensive applicative perception. Understanding pectic substances and their structure, unique depolymerization, and biochemical properties such as a catalytic mechanism and the strong interrelationship among these molecules could immensely enhance their applicability in industries. For instance, gaining knowledge with respect to the versatile molecular heterogeneity of the compounds could be considered as the center of concern to resolve the industrial issues from multiple aspects. In the present review, an effort has been made to orchestrate the fundamental information related to structure, depolymerization characteristics, and classification of pectin as well as the types and biochemical properties of pectinase. Furthermore, various production methods related to the optimization of the product and its significant contribution to the pharmaceutical industry (either pectinase or derived pectic substances) are described in this article.

Vegetable waste represents a serious environmental problem for industries; however, it is also a valuable source of pectic substances. This paper aims to highlight the advances that have been made through studies regarding pectic substances from vegetable wastes, as well as providing an overview of the chemical structure of pectin, extraction and characterisation techniques, and potential applications for pectin in relation to the areas of food and health. Pectin is mainly composed of galacturonic acid and it is one of the most complex polysaccharides in nature. A wide range of vegetable wastes contain a high pectin yield that can be industrially utilised. However, factors such as the type of raw material, the maturation stage of that raw material, and the extraction techniques that are used, affect the structural and functional properties of the pectin, as well as influencing its potential application. This study outlines the different environmentally-friendly techniques that are used to extract pectin, such as microwave, ultrasound, enzymatic and other methods, highlighting their advantages and disadvantages compared with the conventional extraction method. Some techniques are advantageous for industrial use; however, it is necessary to optimise the extraction conditions and to make a financial investment in order to obtain a high yield of pectin in a short amount of time. Characteristics such as galacturonic acid content, the degree of methyl esterification, the degree of acetylation, molar mass and the chemical structure are essential parameters required to define possible applications of pectic substances. In vitro and in vivo studies regarding the properties of pectic substances have shown that these substances can be beneficial to health, with antimicrobial, antitumoral, anti-inflammatory and analgesic effects. Nevertheless, further studies are required to examine the mechanisms of action for these effects to be applied in humans. Consequently, greater understanding about the chemical structure of pectin and its extraction techniques are crucial for the development of new foods and drug formulations. [ABSTRACT FROM AUTHOR]

Today, the healthy nutrition market is one of the most promising market niches; modern consumers increasingly claim fortified products for their diets. One of the ways to increase the biological and physiological value of products is their enrichment with extracts of plant origin. The aim of the work was to study the influence of various factors on the process of hawthorn fruit extraction and determine the optimal parameters of the technological process. The study objects were hawthorn fruit extracts produced by the statistical method of maceration (with stirring). In the extracts obtained, there were determined the quantitative content of tannins and pectin substances, dietary fiber and vitamins. Currently, the global health and wellness food market is steadily growing due to changes in consumer behaviour patterns and developing of healthy self-consciousness. The studies conducted by the authors have shown that extracting of plant materials and the efficiency of biologically active substances extraction are influenced by the following factors: the extractant pH, grinding type and size of raw materials and process parameters. The optimal technological regimes have been established. They are the extraction temperature of 60 °C and extraction time of 30 minutes. The appropriate grinding size of dry hawthorn fruit has been determined to be up to 2.8 mm of a particle. In case of milk being an extractant, a high extraction dynamic of pectic substances and dietary fibers was observed. So, the hawthorn milk extract has been revealed to have higher organoleptic characteristics. [ABSTRACT FROM AUTHOR]

In this paper, the efficiency and mechanisms of two pectinases (pectate lyase (PL) and alkaline pectinase (AL)) to hydrolyze model pectic substances and dissolved and colloidal substances (DCS) of Masson pine bleached chemithermomechanical pulp (BCTMP) were investigated. The cationic demand values of model polygalacturonic acid and DCS could be reduced to about 20% and 60 to 70% by these two pectinases, respectively. However, due to the unmethylated form of the pectic substances in DCS of BCTMP, PL is more efficient than AL. The hydrolysis mechanism of polygalacturonic acid with PL was investigated. The results showed that there was no need to hydrolyze the polymeric pectic substance to their monomers, since a minimum average degree of polymerization (DP) of 6.0 was required for pectic acid to interact strongly with cationic polymers and reduce the efficiency of the latter.

Tomatillo is widely cultivated in Mexico but is little known in other countries. The chemical composition of fruit from field grown plants was investigated during several vegetative seasons. Tomatillo contained a relatively high percentage of dry matter (7-10%) and extract (6.6-7.4%). Its potassium content was lower than that of tomato growing in the same conditions. The content of iron was higher, and that of other elements was comparable, depending on the conditions during the given year. The total sugar content amounted to 2.8-5.7%, depending on the selected population. The percentage of glucose and fructose decreased during ripening and that of saccharose increased. The content of pectic substances was similar as in tomato but the proportions of particular fractions was different. Tomatillo contained more acids than tomato, and showed an especially high citric and malic acid content. The latter decreased drastically during ripening. The content of oxalic acid was 11-18 mg 100 g-1 in ripe fruit and up to 54 mg in unripe. The vitamin C content depended on the selected population and amounted to 8-21 mg 100 g-1, dehydroascorbic acid prevailing. The content of vitamin PP was 0.8-1.3 mg 100 g-1.

Cranberries, lingonberries, blueberries, and food systems based on these berries with different solvents and sugars have been studied. A physicochemical analysis of cranberries, lingonberries, and blueberries has been conducted. Crystalline pectin from cranberries, lingonberries, and blueberries has been isolated to determine the degree of etherification. The gelling ability of the pectic substances has been studied. The effect of different solvents and sugars on the rheological properties of food systems containing pectin has been examined. A comparative estimation of the gelling ability of the pectic substances contained in cranberries, lingonberries, and blueberries and in chitosan and alginate gelling agents has been conducted. The viscous properties have been found to increase in the series: cranberry pectin < lingonberry pectin < blueberry pectin < sodium alginate < chitosan. The complexing ability of pectins with respect to copper and iron ions has been studied and compared to that of casein. Casein exhibits a lower complexing ability with respect to iron ions than pectin. It has been found that the complexing properties of pectin vary with its concentration: the more dilute the solution, the higher the complexing ability of pectin.

This study aimed to investigate the influence of 1 - methylcyclopropene (1-MCP) on the substances involved in the softening of strawberry, cultivar Oso Grande, stored at room temperature, from the municipality of Itutinga, State of Minas Gerais. The parameters evaluated were: firmness, total pectin, percentage of solubilization, activities of the enzymes pectinmethylesterase (PME) (EC 3.1.1.11) and polygalacturonase (PG) (EC 3.2.1.15). It was concluded that 1-MCP delayed the softening of the fruits, since the fruits that were treated with 1-MCP after storage, have shown greater firmness, lower activities of PG and PME, and lower contents of total pectin, soluble pectin and percentage of solubilization.

Pectic substances are structural heteropolysaccharides that occur in the middle lamellae and primary cell walls of higher plants. They are composed of partially methyl-esterified galacturonic acid residues linked by alpha-1, 4-glycosidic bonds. Pectinolytic enzymes are complex enzymes that degrade pectic polymers and there are several classes of enzymes, which include pectin esterases, pectin and pectate lyases and polygalacturonases. Plants, filamentous fungi, bacteria and yeasts are able to produce pectinases. In the industrial world, pectinases are used in fruit juice clarification, in the production of wine, in the extraction of olive oil, fiber degumming and fermentation of tea, coffee and cocoa.

Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc. However, extensive research is needed to establish the role of POS, both as a prebiotic as well as therapeutic agent. This review comprehensively covers different facets of POS, including the nature and chemistry of pectin and POS, potential agricultural residual sources of pectin, pre-treatment methods for facilitating selective extraction of pectin, identification and characterization of POS, health benefits and important applications of POS in food and feed. This review has been compiled to establish a platform for future research in the purification and characterization of POS and forin vivoandin vitrostudies of important POS, so that they could be commercially exploited. [ABSTRACT FROM PUBLISHER]

The objective of this study was to investigate the effect of freezing rates and freeze-thaw cycles on the texture, microstructure and pectic substances (i.e. alcohol insoluble solids (AIS), total pectin (TP), water soluble pectin (WSP) and ammonium oxalate soluble pectin (ASP)) of mango. With repeated freeze-thaw cycles, the WSP, ASP, and drip loss demonstrated a tendency to increase whereas firmness decreased. Although freezing reduced the firmness, fast frozen samples had the highest firmness values. A microstructure analysis showed that the cell walls of the frozen samples were destroyed by ice formation leading to cell shrinkage and collapse. The degradation of the cell walls was more obvious for slow frozen samples than for the fast and medium frozen samples. This study shows that freezing rates and repeated freezing and thawing have an obvious impact on the quality of soft fruits such as the ripe mango. [ABSTRACT FROM AUTHOR]

This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v) and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR). The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively.

Based on the fungus Penicillium verruculosum, we created strains with a complex of extracellular enzymes that contains both cellulolytic enzymes of the fungus and heterologous pectin lyase A from P. canescens and endo-1,4-a-polygalacturonase from Aspergillus niger. The endopolygalacturonase and pectin lyase activities of enzyme preparations obtained from culture media of the producer strains reached 46-53 U/mg of protein and 1.3-2.3 U/mg of protein, respectively. The optimum of temperature and pH for recombinant pectin lyase and endopolygalacturonase corresponded to those described in the literature for these enzymes. The content of heterologous endopolygalacturonase and pectin lyase in the studied enzyme preparations was 4-5% and 23% of the total protein content, respectively. The yield of reducing sugars upon the hydrolysis of sugar beet and apple processing wastes with the most efficient preparation was 41 and 71 g/L, respectively, which corresponded to a polysaccharide conversion of 49% and 65%. Glucose was the main product of the hydrolysis of sugar beet and apple processing wastes. [ABSTRACT FROM AUTHOR]

Nineteen winter squash varieties were investigated to improve the understanding of pectic substance accumulation during fruit growth and to explore differences among cultivars. The results showed that there were significant differences in pectin content among varieties ( P < 0.05). Some Cucurbita maxima varieties were better sources of pectin, in which total pectin (TP) reached 2.47% of fresh wt. Acid soluble pectin (ASP) was the main fraction of pectin in winter squash, and water soluble pectin (WSP) and oxalate soluble pectin (OSP) were minor components of TP. WSP and OSP increased during fruit growth while ASP and TP first increased and then decreased during fruit growth, peaking at different times for early and mid to late maturity varieties. TP differed between species and maturity classes; TP in C. maxima was about 1.5 times that in C. moschata ( P < 0.05). Likewise, TP was 2.3 times higher in early maturity varieties than that in mid to late maturity varieties ( P < 0.05). [ABSTRACT FROM AUTHOR]

We examined the change in the content of pectic substances in tea leaves during the steaming of green tea. In four cultivars of tea leaves, water-soluble pectin (WSP) content increased with steaming time, whereas the dilute hydrochloric acid soluble pectin (HSP) content remained almost constant. A β-elimination reaction proceeds throughout the steaming process, so it was postulated that some water-insoluble forms of pectin in HSP convert to a water-soluble form via β-elimination degradation with increasing steaming time. When tea leaves were steamed, pectin fractions with a molecular weight of 1,100 x 10³ were degraded from water-insoluble HSP and eluted as WSP. Additionally, as steaming time increased, the fraction of smaller molecular weight pectin increased. [ABSTRACT FROM AUTHOR]

The use of enzymes in juice industry has contributed in increasing the yield and production of various types of juices. Pectinolytic enzymes are one of the important groups of enzymes used in fruit processing industry. These are one of the upcoming enzymes of fruit processing industries. These enzymes break down complex polysaccharides of plant tissues into simpler molecules like galacturonic acids. This review discusses the occurrence and nature of pectic substances in fruits, chemistry of pectic substances, types of pectinases and their applications in the fruit processing industry. [ABSTRACT FROM AUTHOR]

Turbidity in fruit juice is caused by polymers such as pectic substances, hemicellulose, cellulose, lignin and starch, and by some compounds such as polyphenols, proteins, arabans, tannins and metals. These colloids need to be degraded to small molecules for manufacturing a clear and stable fruit juice. Following are the pectic enzymes used for the degradation of these colloids; polygalacturonases, pectin esterases, pectin liyases and pectat liyases. In addition, cellulases, hemicellulases, amylases, arabanazes and some other enzymes are also used for the degradation. The enzyme application increases fruit juice yield and press yield and improves clarification process, furthermore the filtration becomes easier and a clear product is obtained due to low viscosity. In this review, important pectolytic enzymes and their substrates including pectic compounds and use of these enzymes in the fruit juice industry are described. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jicama ( Pachyrhizus erosus L.) is a root-based legume that has been cultivated in Mexico for centuries. Pectic polysaccharide from de-starched jicama pomace was extracted using an autoclave-assisted process and physicochemically characterized. The extracted polysaccharide (1.0 g L) was used for the formation of polyelectrolyte complexes (PECs) with water-soluble chitosan (WSCh; 0.5, 1.0 and 2.0 g L). The extraction yield of jicama pectic polysaccharide was 22.8 wt% (dry basis) and infrared spectroscopic analysis showed that it was methoxylated to a small degree. Thermogravimetric analysis indicated that this biopolymer was very stable, its weight loss being 51.2% after heating at 479 °C. Anion-exchange chromatography showed it to have a wide and heterogeneous charge density. The yield of the PECs was dependent on the concentration of WSCh used, it being 13.3, 26.7 and 18.3% with WSCh at 0.5, 1.0 and 2.0 g L, respectively. The PECs had higher thermostability compared with WSCh and this confirmed the complex formation between WSCh and jicama polysaccharide. WSCh is a promising polycation able to interact with low-methoxylated pectic polysaccharide from jicama to produce PECs with uses in a wide variety of specialized applications such as food technology and medicine. Copyright © 2011 Society of Chemical Industry A polyelectrolyte complex was formed as a result of the interaction between pectic polysaccharide from jicama and water-soluble chitosan (20 kg mol). [ABSTRACT FROM AUTHOR]

A methodology has been proposed for establishing an empirical relationship between the parameters, such as per cent removal of pectic substances and waxes, to determine the treatment time in the enzymatic scouring of different cotton fibres for achieving expected absorbency. It is observed that five different varieties of cotton fibres considered in the study behave alike for a given treatment time with respect to removal of pectic substances and waxes during enzymatic scouring. The methodology suggested in this study would help the processors to develop relationships for the conditions used by them in enzymatic scouring to find out the treatment time required to achieve the expected absorbency in any chosen cotton fibre and its blend as long as the conditions used for the purpose are not changed. [ABSTRACT FROM AUTHOR]

• Mucilages from two Opuntia spp. were separated into three fractions. • Two fractions include high M̅ w heteropolysaccharides (4.0 × 103 to 8.0 × 105 g∙mol−1). • Previously undescribed oligosaccharides were found bound to the mucilage. • Complex-structured β-(1–4) linked heterogalactooligosaccharides were found. • Most of the carbohydrate fractions show prebiotic potential. The mucilage extracted from the convection-dried cladodes of O. ficus-indica and O. joconostle, two species of economic importance, delivered three fractions after methanol precipitation. Two were composed of high molar mass polysaccharides, and one included water-soluble mono-, di-, and oligosaccharides. The large polysaccharides have a molar mass range of 4.0 × 103 to 8.0 × 105 g·mol−1 and are consistently composed of galactose, arabinose, xylose, and rhamnose; however, the content of galacturonic acid was different between both fractions and species. Their fermentability by selected probiotics was relatively low, 11–27 % compared to glucose, and decreased with increasing levels of galacturonic acid in the molecules. In the third fraction, previously unreported oligosaccharides were found. These include simple- and complex-structured galactooligosaccharides with arabinosyl-, xylosyl- and galacturonosyl acid residues. Their fermentability by prebiotic species can be ascribed more to their structural characteristics and monosaccharide composition than their molecular dimensions. [ABSTRACT FROM AUTHOR]

Tomato pulp treated at industrial unit conditions was utilized to determine the physical and chemical changes on pectin substances properties and its correlation to the consistency of tomato pulp, hot break pretreated product, concentrated pulp at 70oC/30 min and sterilized pulp at 102oC/10 min. The assays carried out were: apparent viscosity, serum separation degree, precipitate weight ratio, insoluble solids and pectic substances as uronic acid, fractionated according to their solubility in water, 0.2% ammonium oxalate, 0.05N hydrochloric acid and 0.05N sodium hydroxide solutions. Concentration and sterilization cause reduction in the apparent viscosity, the precipitate weight ratio and increasing of the serum separation degree of the suspension compare to tomato pulp submitted only to pre-treatment and those conditions didn't affect significantly the total uronic acid and insoluble solids in water. However, changes occurred on chemical composition, detected into fractions of pectic substances expressed as uronic acid in all samples; results for pre-treated pulp sample to sterilized pulp samples (final product) show a high water solubilization of the fractions of the pectic substances, around 31%, confirmed by an increment of 24% in the water soluble fraction. A high correlation was established between the concentration of water-insoluble fractions and apparent viscosity, precipitate weight ratio and serum separation degree. [ABSTRACT FROM AUTHOR]

Abstract: Pectinases or petinolytic enzymes, hydrolyze pectic substances. They have a share of 25% in the global sales of food enzymes. Pectinases are one of the most widely distributed enzymes in bacteria, fungi and plants. Protopectinases, polygalacturonases, lyases and pectin esterases are among the extensively studied pectinolytic enzymes. Protopectinases catalyze the solubilization of protopectin. Polygalacturonases hydrolyze the polygalacturonic acid chain by addition of water and are the most abundant among all the pectinolytic enzymes. Lyases catalyze the trans-eliminative cleavage of the galacturonic acid polymer. Pectinesterases liberate pectins and methanol by de-esterifying the methyl ester linkages of the pectin backbone. Pectinolytic enzymes are of significant importance in the current biotechnological era with their all-embracing applications in fruit juice extraction and its clarification, scouring of cotton, degumming of plant fibers, waste water treatment, vegetable oil extraction, tea and coffee fermentations, bleaching of paper, in poultry feed additives and in the alcoholic beverages and food industries. The present review mainly contemplates on the types and structure of pectic substances, the classification of pectinolytic enzymes, their assay methods, physicochemical and biological properties and a bird''s eye view of their industrial applications. [Copyright &y& Elsevier]

The effect of different postharvest treatments (film wrapping in conventional and biodegradable materials, foodtainer, surface coating) were evaluated in respect to their suitability to prevent quality loss of bioactive compounds in highly perishable fruits and vegetables. In lettuce, film packaging did not show any beneficial effects on pectic substances and pigments. However, in pepino dulce fruits the use of foodtainer maintained the β-carotene and chlorophyll contents, whereas Semperfresh coating led to a desired inhibition of pectin degradation. Starch coating and OPP-Coex-film packaging prevented the loss of soluble pectins in radish, whereas glucosinolates were only maintained by film packaging. [ABSTRACT FROM AUTHOR]

The role of calcium in protecting plant tissue from infection by Botrytis cinerea was studied in cucumber fruit. A self-defense reaction, consisting of an increase in cell-wall-bound Ca, occurred in the plant tissue after an injury or an infection. However, it was not sufficient to protect the tissue from the spread of the fungus, which is accompanied by pectic substance digestion. The degradation induced mainly a decrease in acid- and chelator-soluble pectin levels, and an increase in water-soluble pectin. Ca treatment of the fruit prior to infection could amplify the cell-wall-bound Ca and therefore lessen pectin digestion by fungal pectinolytic enzymes. [ABSTRACT FROM AUTHOR]

Copyright of Potato Research is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cortical parenchyma cell wall of the naturally grown carrot root was investigated using quick-freeze, deep-etching electron microscopy. The primary cell wall consisted of numerous fibrous components about 10 nm in diameter, and granular components around and among the fibrous components. When the tissue was treated with polygalacturonase, the granular components were digested away from the cell wall, and the fibrous components in the disordered alignment remained. The granular components might be of pectic substances and have a cementing role among the fibrous components. The middle lamella was formed by the fibrous, reticular and granular substances. A calcium-induced pectic gel showed a reticular structure composed of fibrillar materials 3 to 15nm in diameter. This suggests that the fibrous components are considered to contain the fibrillar type of pectic substances. When the tissue was treated with polygalacturonase, a meshwork structure still remained in the middle lamella and the intercellular space located at the tricellular junction, where a crossed-layered structure of the meshwork was observed and remained even after the tissue was boiled for 30 min before the enzyme treatment. These facts suggest that the pectic substances might not contribute to the meshwork structure in the middle lamella. [ABSTRACT FROM PUBLISHER]

A procedure was developed to isolate protoplasts rapidly from carrot ( Daucus carota L. cv. Danvers) cells in liquid culture. High purity of cell-wall-degrading enzymes and ease of isolation each contributed to maintenance of viability and initiation of regeneration of the cell wall by a great majority of the protoplasts. We used this system to re-evaluate the chemical structure and physical properties of the incipient cell wall. Contrary to other reports, callose, a (1 → 3)β-d-glucan whose synthesis is associated with wounding, was not a component of the incipient wall of carrot protoplasts. Intentional wounding by rapid shaking or treatment with dimethyl sulfoxide initiated synthesis of callose, detected both by Aniline blue and Cellufluor fluorescence of dying cells and by an increase in (1 → 3)-linked glucan quantified in methylation analyses. Linkage analyses by gas-liquid chromatography of partially methylated alditol-acetate derivatives of polysaccharides of the incipient wall of protoplasts and various fractions of the cell walls of parent cells showed that protoplasts quickly initiated synthesis of the same pectic and hemicellulosic polymers as normal cells, but acid-resistant cellulose was formed slowly. Complete formation of the wall required 3 d in culture, and at least 5 d were required before the wall could withstand turgor. Pectic substances synthesized by protoplasts were less anionic than those of parent cells, and became more highly charged during wall regeneration. We propose that de-esterification of the carboxyl groups of pectin uronic-acid units permits formation of a gel that envelops the protoplast, and the rigid cellulose-hemicellulose frame-work forms along with this gel matrix. [ABSTRACT FROM AUTHOR]

Both pectin and pectinase are vitally imperative biomolecules in the biotechnological sector. These molecules are a feasible non-toxic contrivance of nature with extensive applicative perception. Understanding pectic substances and their structure, unique depolymerization, and biochemical properties such as a catalytic mechanism and the strong interrelationship among these molecules could immensely enhance their applicability in industries. For instance, gaining knowledge with respect to the versatile molecular heterogeneity of the compounds could be considered as the center of concern to resolve the industrial issues from multiple aspects. In the present review, an effort has been made to orchestrate the fundamental information related to structure, depolymerization characteristics, and classification of pectin as well as the types and biochemical properties of pectinase. Furthermore, various production methods related to the optimization of the product and its significant contribution to the pharmaceutical industry (either pectinase or derived pectic substances) are described in this article., (Copyright © 2020 Satapathy, Rout, Kerry, Thatoi and Sahoo.)

Of three molecular forms of polygalacturonases synthesized by Aspergillus alliaceus on glucose media, two were exopolygalacturonases (exoPG and exoPG) and one was an endopolygalacturonase (endoPG). Low-methoxylated beet pectin was the preferred substrate for the endoPG and exoPG whereas pectic acid was the optimal substrate for exoPG. The highest activities of endoPG, exoPG and exoPG were at pH 5.5, 3.5, and 6.0 and at 35, 45 to 50 and 35°C, respectively. Disks of potato-tuber tissue were macerated by endoPG, but not by exoPG or exoPG. [ABSTRACT FROM AUTHOR]