{{Short description|Structural carbohydrate in the cell walls of land plants and some algae}} {{Distinguish|Pecten (biology)|Pecten oculi|Pecten (bivalve)}} {{cs1 config|name-list-style=vanc|display-authors=6}} {{Use dmy dates |date=July 2021}} [[Image:Pectin.jpg|thumb|Commercially produced powder of pectin, extracted from citrus fruits]] '''Pectin''' ({{langx|grc|πηκτικός}} {{Transliteration|grc|pēktikós}}: 'congealed' and 'curdled') is a heteropolysaccharide, a structural polymer contained in the cell walls and middle lamellae of terrestrial plants.<ref name="Liddell">{{LSJ|phktiko/s|πηκτικός|ref}}</ref> The principal chemical component of pectin is galacturonic acid (a sugar acid derived from galactose) which was isolated and described by Henri Braconnot in 1825.<ref name="Braconnot-1825">{{cite journal | vauthors = Braconnot H | date = 1825 | url = https://books.google.com/books?id=1Zg5AAAAcAAJ&pg=PA173 | title = Recherches sur un nouvel acide universellement répandu dans tous les vegetaux | trans-title = Investigations into a new acid spread throughout all plants | journal = Annales de chimie et de physique | issue = 2 | volume = 28 | pages = 173–178 | quote = From page 178: ... ''je propose le nom ''pectique'', de {{lang|grc|πηχτες}}, coagulum,'' ... (I propose the name ''pectique'', from {{lang|grc|πηχτες}} [pectes], coagulum [coagulated material, clot, curd]) | access-date = 8 January 2016 | archive-date = 7 September 2024 | archive-url = https://web.archive.org/web/20240907194655/https://books.google.com/books?id=1Zg5AAAAcAAJ&pg=PA173#v=onepage&q&f=false | url-status = live }}</ref><ref name="Keppler-2006">{{cite journal | vauthors = Keppler F, Hamilton JT, Brass M, Röckmann T | title = Methane emissions from terrestrial plants under aerobic conditions | journal = Nature | volume = 439 | issue = 7073 | pages = 187–191 | date = January 2006 | pmid = 16407949 | doi = 10.1038/nature04420 | s2cid = 2870347 | bibcode = 2006Natur.439..187K }}</ref>{{Dubious|date=December 2024|reason=Uh, he discovered pectin, not galactic acid.}} Commercially produced pectin is a white-to-light-brown powder, produced from citrus fruits for use as an edible gelling agent, especially in jams and jellies, dessert fillings, medications, and sweets; as a food stabiliser in fruit juices and milk drinks;<ref name="Gerlat-2000">{{cite magazine| vauthors = Gerlat P |date=15 November 2000|title=Beverage Stabilizers|magazine=Food Product Design Magazine|via=Food Ingredients Online - for the food ingredients industry|url=https://www.foodingredientsonline.com/doc/beverage-stabilizers-0001|url-status=live|archive-url=https://web.archive.org/web/20220812141340/https://www.foodingredientsonline.com/doc/beverage-stabilizers-0001|archive-date=12 August 2022|access-date=24 January 2023}}</ref> and as a source of dietary fiber.

== Biology ==

=== Natural occurrence === thumb|The peels of citrus fruits naturally contain large amounts of pectin. Pears, apples, guavas, quince, plums, gooseberries, and oranges and other citrus fruits contain large amounts of pectin, while soft fruits, like cherries, grapes, and strawberries, contain small amounts of pectin.{{Citation needed|date=July 2018}}

Typical levels of pectin in fresh fruits and vegetables are: * Apples, 1–1.5% * Apricots, 1% * Cherries, 0.4% * Oranges, 0.5–3.5% * Carrots 1.4% * Citrus peels, 30% * Rose hips, 15%<ref name="Wichtl-2004">{{cite book |title=Herbal Drugs and Phytopharmaceuticals: a handbook for practice on a scientific basis |vauthors=Wichtl M |date=January 2004 |publisher=Medpharm; CRC Press |isbn=978-0-8493-1961-7 |edition=3rd expanded and completely rev. |location=Stuttgart : Boca Raton, FL |page=520 |chapter=Monograph: Rosae Pseudofrutus (Rose Hips) |access-date=14 March 2023 |chapter-url=https://books.google.com/books?id=7PRyMWo5e28C&dq=analysis+pectin+rose+hip+15%25&pg=PA520 |archive-url=https://web.archive.org/web/20231012173031/https://books.google.com/books?id=7PRyMWo5e28C&dq=analysis+pectin+rose+hip+15%&pg=PA520 |archive-date=12 October 2023 |url-status=live}}</ref> Pectin is composed of complex polysaccharides that are present in the primary cell walls of a plant, and are abundant in the green parts of terrestrial plants.<ref name="Bidhendi-2020">{{cite journal | vauthors = Bidhendi AJ, Chebli Y, Geitmann A | title = Fluorescence visualization of cellulose and pectin in the primary plant cell wall | journal = Journal of Microscopy | volume = 278 | issue = 3 | pages = 164–181 | date = June 2020 | pmid = 32270489 | doi = 10.1111/jmi.12895 | s2cid = 215619998 }}</ref> Pectin is the principal component of the middle lamella, where it binds cells. Pectin is deposited by exocytosis into the cell wall via vesicles produced in the Golgi apparatus.<ref name="Braidwood-2014">{{cite journal | vauthors = Braidwood L, Breuer C, Sugimoto K | title = My body is a cage: mechanisms and modulation of plant cell growth | journal = The New Phytologist | volume = 201 | issue = 2 | pages = 388–402 | date = January 2014 | pmid = 24033322 | doi = 10.1111/nph.12473 | doi-access = free | bibcode = 2014NewPh.201..388B }}</ref> The amount, structure and chemical composition of pectin is different among plants, within a plant over time, and in various parts of a plant. Pectin is an important cell wall polysaccharide that allows primary cell wall extension and plant growth.<ref name="Bidhendi-2016">{{cite journal | vauthors = Bidhendi AJ, Geitmann A | title = Relating the mechanics of the primary plant cell wall to morphogenesis | journal = Journal of Experimental Botany | volume = 67 | issue = 2 | pages = 449–461 | date = January 2016 | pmid = 26689854 | doi = 10.1093/jxb/erv535 | url = https://academic.oup.com/jxb/article-pdf/67/2/449/9366354/erv535.pdf | access-date = 30 May 2020 | url-status = live | doi-access = free | archive-url = https://web.archive.org/web/20180113093611/https://academic.oup.com/jxb/article-pdf/67/2/449/9366354/erv535.pdf | archive-date = 13 January 2018 }}</ref> During fruit ripening, pectin is broken down by the enzymes pectinase and pectinesterase, in which process the fruit becomes softer as the middle lamellae break down and cells become separated from each other.<ref name="Grierson-1986">{{cite journal | vauthors = Grierson D, Maunders MJ, Slater A, Ray J, Bird CR, Schuch W, Holdsworth MJ, Tucker GA, Knapp JE |year=1986|title=Gene expression during tomato ripening|journal=Philosophical Transactions of the Royal Society of London B|volume=314|issue=1166|pages=399–410|doi=10.1098/rstb.1986.0061|bibcode=1986RSPTB.314..399G|doi-access=}}</ref> A similar process of cell separation caused by the breakdown of pectin occurs in the abscission zone of the petioles of deciduous plants at leaf fall.{{Citation needed|date = March 2015}}

=== Human nutrition === Pectin is a natural part of the human diet and although not digested in the small intestine, it is fermented in the large intestine. It has a positive effect on decreasing overall LD L cholesterol levels as well as lowering post-prandial glucose levels.<ref>{{Cite journal |last=Weber |first=Annika M. |last2=Pascale |first2=Nélida |last3=Gu |first3=Fangjie |last4=Ryan |first4=Elizabeth P. |last5=Respondek |first5=Frederique |date=June 2025 |title=Nutrition and health effects of pectin: A systematic scoping review of human intervention studies |url=https://www.cambridge.org/core/journals/nutrition-research-reviews/article/nutrition-and-health-effects-of-pectin-a-systematic-scoping-review-of-human-intervention-studies/01BF0759F09A2BBC419F333B8B1D4FF9 |journal=Nutrition Research Reviews |language=en |volume=38 |issue=1 |pages=306–323 |doi=10.1017/S0954422424000180 |issn=0954-4224|doi-access=free }}</ref> The daily intake of pectin from fruits and vegetables can be estimated to be around 5&nbsp;g if approximately 500&nbsp;g of fruits and vegetables are consumed per day.{{Citation needed|date = July 2024}}

In human digestion, pectin binds to cholesterol in the gastrointestinal tract and slows glucose absorption by trapping carbohydrates. Pectin is thus a soluble dietary fiber. In non-obese diabetic (NOD) mice pectin has been shown to increase the incidence of autoimmune type 1 diabetes.<ref name="Toivonen-2014">{{cite journal | vauthors = Toivonen RK, Emani R, Munukka E, Rintala A, Laiho A, Pietilä S, Pursiheimo JP, Soidinsalo P, Linhala M, Eerola E, Huovinen P, Hänninen A | title = Fermentable fibres condition colon microbiota and promote diabetogenesis in NOD mice | journal = Diabetologia | volume = 57 | issue = 10 | pages = 2183–2192 | date = October 2014 | pmid = 25031069 | doi = 10.1007/s00125-014-3325-6 | doi-access = free }}</ref>

A study found that, after consumption of fruit, the concentration of methanol in the human body increased by as much as an order of magnitude due to the degradation of natural pectin (which is esterified with methanol) in the colon.<ref name="Lindinger-1997">{{cite journal | vauthors = Lindinger W, Taucher J, Jordan A, Hansel A, Vogel W | title = Endogenous production of methanol after the consumption of fruit | journal = Alcoholism: Clinical and Experimental Research | volume = 21 | issue = 5 | pages = 939–943 | date = August 1997 | pmid = 9267548 | doi = 10.1111/j.1530-0277.1997.tb03862.x }}</ref>

Consumption of pectin has been shown to slightly (3–7%) reduce blood LDL cholesterol levels. The effect depends upon the source of pectin; apple and citrus pectins were more effective than orange pulp fibre pectin.<ref name="Brouns-2012">{{cite journal |vauthors=Brouns F, Theuwissen E, Adam A, Bell M, Berger A, Mensink RP |date=May 2012 |title=Cholesterol-lowering properties of different pectin types in mildly hyper-cholesterolemic men and women |journal=European Journal of Clinical Nutrition |volume=66 |issue=5 |pages=591–599 |doi=10.1038/ejcn.2011.208 |pmid=22190137 |doi-access=free}}</ref> The mechanism appears to be an increase of viscosity in the intestinal tract, leading to a reduced absorption of cholesterol from bile or food.<ref name="Sriamornsak-2003">{{cite journal |vauthors=Sriamornsak P |year=2003 |title=Chemistry of Pectin and its Pharmaceutical Uses: A Review |url=http://www.journal.su.ac.th/index.php/suij/article/viewFile/48/48 |journal=Silpakorn University International Journal |volume=3 |issue=1–2 |page=206 |archive-url=https://web.archive.org/web/20120603005249/http://www.journal.su.ac.th/index.php/suij/article/viewFile/48/48 |archive-date=3 June 2012 |access-date=23 August 2007}}</ref> In the large intestine and colon, microorganisms degrade pectin and liberate short-chain fatty acids that have a positive prebiotic effect.<ref name="Gómez-2014">{{cite journal |vauthors=Gómez B, Gullón B, Remoroza C, Schols HA, Parajó JC, Alonso JL |date=October 2014 |title=Purification, characterization, and prebiotic properties of pectic oligosaccharides from orange peel wastes |journal=Journal of Agricultural and Food Chemistry |volume=62 |issue=40 |pages=9769–9782 |bibcode=2014JAFC...62.9769G |doi=10.1021/jf503475b |pmid=25207862}}</ref>

=== Other === Pectin has been observed to have some function in repairing the DNA of some types of plant seeds, usually desert plants.<ref name="Huang-2004">{{cite journal | vauthors = Huang Z, Gutterman Y, Osborne DJ |title=Value of the mucilaginous pellicle to seeds of the sand-stabilizing desert woody shrub Artemisia sphaerocephala (Asteraceae) |journal=Trees |date=30 July 2004 |volume=18 |issue=6 |pages=669–676 |doi=10.1007/s00468-004-0349-4 |bibcode=2004Trees..18..669H |s2cid=37031814 }}</ref> Pectinaceous surface pellicles, which are rich in pectin, create a mucilage layer that holds in dew that helps the cell repair its DNA.<ref name="Huang-2008">{{cite journal | vauthors = Huang Z, Boubriak I, Osborne DJ, Dong M, Gutterman Y | title = Possible role of pectin-containing mucilage and dew in repairing embryo DNA of seeds adapted to desert conditions | journal = Annals of Botany | volume = 101 | issue = 2 | pages = 277–283 | date = January 2008 | pmid = 17495979 | pmc = 2711012 | doi = 10.1093/aob/mcm089 }}</ref>

==Chemistry== === Definition and structure === Pectin is a heteropolysaccharide with a high proportion of D-galacturonic acid (≈ 65%) in its repeat units''.''<ref>{{Cite journal |last1=Dranca |first1=Florina |last2=Oroian |first2=Mircea |date=2018-11-01 |title=Extraction, purification and characterization of pectin from alternative sources with potential technological applications |journal=Food Research International |volume=113 |pages=327–350 |doi=10.1016/j.foodres.2018.06.065 |pmid=30195527 |issn=0963-9969}}</ref> As the polymer's main chain contains α-L-rhamnose in addition to galacturonic acid, the systematic name for pectin is rhamno-galacturonic acid. The incorporation of rhamnose units disrupts the otherwise linear poly(galacturonic acid) chain, introducing bends (or "kinks"). Many rhamnose units in pectin carry oligomeric side chains of neutral sugars such as arabinose, galactose, or xylose. These branched sections are referred to as "hairy" regions, while the unbranched stretches composed mainly of galacturonic acid are termed "smooth" regions. In further detail, the hairy and smooth regions can be divided into distinct structural domains (that exist within the same pectin molecule): Smooth regions comprise homogalacturonan (HG), xylogalacturonan (XGA), and apiogalacturonan (APGA), while the hairy regions are made up of rhamnogalacturonan I (RG-I) and rhamnogalacturonan II (RG-II).<ref name="Barrera Pectin Review">{{Cite journal |last1=Barrera-Chamorro |first1=Luna |last2=Fernandez-Prior |first2=África |last3=Rivero-Pino |first3=Fernando |last4=Montserrat-de la Paz |first4=Sergio |date=2025-01-15 |title=A comprehensive review on the functionality and biological relevance of pectin and the use in the food industry |journal=Carbohydrate Polymers |volume=348 |issue=Pt A |article-number=122794 |doi=10.1016/j.carbpol.2024.122794 |pmid=39562070 |issn=0144-8617|doi-access=free |hdl=10261/383768 |hdl-access=free }}</ref>

The carboxyl groups of polygalacturonic acid are frequently esterified with methanol or acetic acid. The degree of esterification and acetylation varies depending on the source of the pectin and has a decisive impact on its chemical properties. Pectins are therefore classified according to their degree of methylation (DM) and degree of acetylation (DA), which represent the ratio of esterified galacturonic acids (methylated or acetylated) to total galacturonic acids. Functionally, three types of pectins are distinguished:<ref name=":0">{{Cite journal |last1=Gawkowska |first1=Diana |last2=Cybulska |first2=Justyna |last3=Zdunek |first3=Artur |date=2018-07-11 |title=Structure-Related Gelling of Pectins and Linking with Other Natural Compounds: A Review |journal=Polymers |language=en |volume=10 |issue=7 |page=762 |doi=10.3390/polym10070762 |doi-access=free |issn=2073-4360 |pmc=6404037 |pmid=30960687}}</ref>

* '''Pectic acids''': degree of methylation less than 5% (DM<5) * '''Weakly methylated (LM) pectins''': degree of methylation less than 50% (DM<50) * '''Highly methylated (HM) pectins''': degree of methylation greater than 50% (DM>50)

Amidated pectin shows enhanced tolerance to varying calcium concentrations. Thiolated pectin, capable of forming disulfide crosslinks, exhibits superior gelling properties beneficial for pharmaceutical and food applications.<gallery> File:D-galacturonic acid haworth.png|Main chain monomer: Galacturonic acid (GalA; a sugar acid) File:Beta-L-Rhamnopyranose.svg|Main chain monomer: Rhamnose (Rha) File:Alpha-D-Galactopyranose.svg|Side chain monomer: Galactose (Gal) File:Alpha-D-Arabinopyranose.svg|Side chain monomer: Arabinose (Ara) File:Alpha-D-Xylopyranose.svg|Side chain monomer: Xylose (Xyl) </gallery>

{| class="wikitable float-left skin-invert" !Structural features of various pectins |- |300x300px Section of the pectin main chain:<br /> Poly-α-(1→4)-galacturonic acid. |- |300x300px Partially esterified section of the pectin main chain |- |300x300px Rhamnogalacturonan: backbone with a "kink" <br /> due to incorporated rhamnose |}

frameless|416x416px

==== Structural domains ==== Pectin is often described as having alternating 'smooth' and 'hairy' regions, with the 'hairy' regions representing the branched rhamnogalacturonan I and rhamnogalacturonan II, and the 'smooth' regions corresponding to the linear homogalacturonan backbone.<ref>{{Cite journal |last1=Pang |first1=Yunrui |last2=Peng |first2=Zhigang |last3=Ding |first3=Kan |date=November 2024 |title=An in-depth review: Unraveling the extraction, structure, bio-functionalities, target molecules, and applications of pectic polysaccharides |url=https://linkinghub.elsevier.com/retrieve/pii/S0144861724006830 |journal=Carbohydrate Polymers |language=en |volume=343 |article-number=122457 |doi=10.1016/j.carbpol.2024.122457 |pmid=39174094 |url-access=subscription }}</ref> More specifically, pectin consists of different galacturonic acid–containing domains—mainly homogalacturonan (HG), rhamnogalacturonan I (RG-I), and rhamnogalacturonan II (RG-II)—which differ in their sugar composition and linkage patterns. Additionally, xylogalacturonan (XGA) and apiogalacturonan (APGA) are often considered to be pectin because they have the same backbone as homogalacturonan.<ref name="Barrera Pectin Review" />

Homogalacturonan is a linear homopolymer of ''α''-(1 → 4)-linked D-galacturonic acid residues that comprises ~65 % of pectin.<ref>{{Cite journal |last1=Du |first1=Juan |last2=Anderson |first2=Charles T. |last3=Xiao |first3=Chaowen |date=2022-04-11 |title=Dynamics of pectic homogalacturonan in cellular morphogenesis and adhesion, wall integrity sensing and plant development |url=https://www.nature.com/articles/s41477-022-01120-2 |journal=Nature Plants |language=en |volume=8 |issue=4 |pages=332–340 |doi=10.1038/s41477-022-01120-2 |pmid=35411046 |bibcode=2022NatPl...8..332D |osti=1865662 |issn=2055-0278}}</ref> Generally, homogalacturonan comprises D-galacturonic acid residues monomers in long stretches of at least 72 to 100 residues linked together.<ref name="Barrera Pectin Review" />

Rhamnogalacturonan I is a repeating disaccharide of [→4-''α''-D-GalA-(1 → 2)-''α''-L-Rha-(1→], i. e. an alternating copolymer of galacturonic acid and rhammnose, with many ''O-4'' positions containing other neutral sugars, such as D-galactose or L-arabinose.<ref>{{Cite journal |last1=Wagstaff |first1=Ben A. |last2=Zorzoli |first2=Azul |last3=Dorfmueller |first3=Helge C. |date=2021-02-26 |title=NDP-rhamnose biosynthesis and rhamnosyltransferases: building diverse glycoconjugates in nature |url=https://portlandpress.com/biochemj/article/478/4/685/227880/NDP-rhamnose-biosynthesis-and |journal=Biochemical Journal |language=en |volume=478 |issue=4 |pages=685–701 |doi=10.1042/BCJ20200505 |pmid=33599745 |issn=0264-6021|url-access=subscription }}</ref> The length of the backbone of rhamnogalacturonan I is about 100 to 300 repeating units. Side chains varying by plant sources, such as arabinan, ''β''-(1 → 4)-galactan, type I arabinogalactan (AG-I), and type II arabinogalactan (AG-II) exist. Arabinan consist of ''α''-(1 → 5)-linked L-arabinose backbone, which is usually substituted with ''α''-L-arabinose in different linkages. AG-I is composed out of a ''β''-(1 → 4)-linked D-galactose backbone with ''α''-L-arabinose residues attached to the ''O-3'' position. The terminal galactose of ''β''-(1 → 4) galactan is frequently linked to L-arabinose by ''α''-(1 → 5) glycoside bonds. Type II arabinogalactan is composed of a ''β''-(1 → 3)-linked D-Gal backbone, containing short side chains of ''α''-L-Ara-(1 → 6)-[''β''-D-Gal-(1 → 6)]n. The galactosyl residues of the side chains can be substituted with ''α''-(1 → 3)-linked L-arabinose residues.<ref>{{Cite journal |last1=Kaczmarska |first1=Adrianna |last2=Pieczywek |first2=Piotr M. |last3=Cybulska |first3=Justyna |last4=Zdunek |first4=Artur |date=February 2022 |title=Structure and functionality of Rhamnogalacturonan I in the cell wall and in solution: A review |journal=Carbohydrate Polymers |language=en |volume=278 |article-number=118909 |doi=10.1016/j.carbpol.2021.118909 |pmid=34973730 |doi-access=free }}</ref> Type II arabinogalactan is mainly associated with proteins (3–8 %), so called arabinogalactan proteins (AGPs), which are rich in proline/hydroxyproline, alanine, serine, and threonine.<ref>{{Cite journal |last1=Leszczuk |first1=Agata |last2=Kalaitzis |first2=Panagiotis |last3=Kulik |first3=Joanna |last4=Zdunek |first4=Artur |date=2023-01-20 |title=Review: structure and modifications of arabinogalactan proteins (AGPs) |journal=BMC Plant Biology |language=en |volume=23 |issue=1 |article-number=45 |doi=10.1186/s12870-023-04066-5 |doi-access=free |issn=1471-2229 |pmc=9854139 |pmid=36670377 |bibcode=2023BMCPB..23...45L }}</ref> D-galacturonic acid residues residues in the backbone of rhamnogalacturonan I may be highly O-acylated on ''O-2'' and/or ''O-3'', but they are not usually methyl esterified. Ferulic acid groups in rhamnogalacturonan I may be ester-linked to ''O-2'' of the arabinose residues and to O-6 of the galactose residues.<ref name="Barrera Pectin Review" />

Another structural type of pectin is rhamnogalacturonan II (RG-II), which is a less frequent, complex, highly branched polysaccharide.<ref name="Ccrc-RGII">{{cite web | url = http://www.ccrc.uga.edu/~mao/rg2/intro.htm | title = Rhamnogalacturonan II | work = www.ccrc.uga.edu | archive-url = https://web.archive.org/web/20091003140059/http://www.ccrc.uga.edu/~mao/rg2/intro.htm | archive-date = 3 October 2009 | access-date = 16 July 2012 }}</ref> Rhamnogalacturonan II is classified by some authors within the group of substituted galacturonans since the rhamnogalacturonan II backbone is made exclusively of <small>D</small>-galacturonic acid units.<ref name="Barrera Pectin Review" />

=== Molecular weight === The molecular weight of isolated pectine greatly varies by the source and the method of isolation.<ref>{{cite journal | vauthors = Singaram A, Guruchandran S, Ganesan N | title = Review on functionalized pectin films for active food packaging | journal = Packaging Technology and Science | volume = 37 | issue = 4 | pages = 237–262 | date = 2024 | doi = 10.1002/pts.2793 }}</ref> Values have been reported as low as 28 kDa for apple pomace<ref>{{cite journal | vauthors = Wang X, Chen Q, Lü X | title = Pectin extracted from apple pomace and citrus peel by subcritical water | journal = Food Hydrocoll. | date = 2014 | volume = 38 | pages = 129–137 | doi=10.1016/J.FOODHYD.2013.12.003}}</ref> up to 753 kDa for sweet potato peels.<ref>{{cite journal | vauthors = Arachchige M, Mu T, Ma M | title = Structural, physicochemical and emulsifying properties of sweet potato pectin treated by high hydrostatic pressure and/or pectinase: a comparative study | journal=J Sci Food Agric | date = 2020 | volume = 100 | issue = 13 | pages = 4911–4920 | doi = 10.1007/s11696-018-0500-0 | pmid = 32483850 }}</ref>

=== Substitutions === In nature, around 80 percent of carboxyl groups of galacturonic acid are esterified with methanol. This proportion is decreased to a varying degree during pectin extraction. Pectins are classified as high- versus low-methoxy pectins (short HM-pectins versus LM-pectins), with more or less than half of all the galacturonic acid esterified.<ref name="Liang-2012">{{cite journal | vauthors = Liang RH, Chen J, Liu W, Liu CM, Yu W, Yuan M, Zhou XQ | title = Extraction, characterization and spontaneous gel-forming property of pectin from creeping fig (Ficus pumila Linn.) seeds | journal = Carbohydrate Polymers | volume = 87 | issue = 1 | pages = 76–83 | date = January 2012 | pmid = 34663033 | doi = 10.1016/j.carbpol.2011.07.013 }}</ref> The ratio of esterified to non-esterified galacturonic acid determines the behaviour of pectin in food applications – HM-pectins can form a gel under acidic conditions in the presence of high sugar concentrations, while LM-pectins form gels by interaction with divalent cations, particularly Ca<sup>2+</sup>, according to the idealized 'egg box' model, in which ionic bridges are formed between calcium ions and the ionised carboxyl groups of the galacturonic acid.<ref name="Durand-1990">{{cite journal | vauthors = Durand D, Bertrand C, Clark AH, Lips A | title = Calcium-induced gelation of low methoxy pectin solutions--thermodynamic and rheological considerations | journal = International Journal of Biological Macromolecules | volume = 12 | issue = 1 | pages = 14–18 | date = February 1990 | pmid = 2083236 | doi = 10.1016/0141-8130(90)90076-M }}</ref><ref name="Migliori-2010">{{cite journal | vauthors = Migliori M, Gabriele D, Checchetti A, Battipede B | year = 2010| title = Compatibility analysis of pectin at different esterification degree from intrinsic viscosity data of diluted ternary solutions | journal = Reactive and Functional Polymers | volume = 70 | issue = 10| pages = 863–867 | doi = 10.1016/j.reactfunctpolym.2010.07.011 | bibcode = 2010RFPol..70..863M}}</ref><ref name="Liang-2012" />

The non-esterified galacturonic acid units can be either free acids (carboxyl groups) or salts with sodium, potassium, or calcium. The salts of partially esterified pectins are called pectinates, if the degree of esterification is below 5 percent the salts are called pectates, the insoluble acid form, pectic acid.<ref name=":0" />

Some plants, such as sugar beet, potatoes and pears, contain pectins with acetylated galacturonic acid in addition to methyl esters. Acetylation prevents gel-formation but increases the stabilising and emulsifying effects of pectin.{{Citation needed|date=July 2018}}

Amidated pectin is a modified form of pectin. Here, some of the galacturonic acid is converted with ammonia to carboxylic acid amide. These pectins are more tolerant of varying calcium concentrations that occur in use.<ref name="Belitz-2004">{{cite book | vauthors = Belitz HD, Grosch W, Schieberle P | title = Food Chemistry | publisher = Springer | location = Berlin | date = April 2004 }}</ref>

Thiolated pectin exhibits substantially improved gelling properties since this thiomer is able to crosslink via disulfide bond formation. These high gelling properties are advantageous for various pharmaceutical applications and applications in food industry.<ref name="Majzoob-2006">{{cite journal | vauthors = Majzoob S, Atyabi F, Dorkoosh F, Kafedjiiski K, Loretz B, Bernkop-Schnürch A | title = Pectin-cysteine conjugate: synthesis and in-vitro evaluation of its potential for drug delivery | journal = The Journal of Pharmacy and Pharmacology | volume = 58 | issue = 12 | pages = 1601–1610 | date = December 2006 | pmid = 17331323 | doi = 10.1211/jpp.58.12.0006 | s2cid = 24127477 | doi-access = free }}</ref><ref name="Perera-2010">{{cite journal | vauthors = Perera G, Hombach J, Bernkop-Schnürch A | title = Hydrophobic thiolation of pectin with 4-aminothiophenol: synthesis and in vitro characterization | journal = AAPS PharmSciTech | volume = 11 | issue = 1 | pages = 174–180 | date = March 2010 | pmid = 20101485 | pmc = 2850493 | doi = 10.1208/s12249-009-9370-7 | s2cid = 25025639 }}</ref><ref name="Chen-2023">{{cite journal | vauthors = Chen J, Cui Y, Zhang S, Ma Y, Yang F | title = Compound treatment of thiolated citrus high-methoxyl pectin and sodium phosphate dibasic anhydrous improved gluten network structure | journal = Food Chemistry | volume = 404 | issue = Pt B | article-number = 134770 | date = March 2023 | pmid = 36332584 | doi = 10.1016/j.foodchem.2022.134770 | s2cid = 253214393 }}</ref>

Amidated pectins behave like low-ester pectins but need less calcium and are more tolerant of excess calcium. Also, gels from amidated pectin are thermoreversible; they can be heated and after cooling solidify again, whereas conventional pectin-gels will afterwards remain liquid.{{Citation needed|date=July 2018}}

=== Gelation === In high-methoxy pectins at soluble solids content above 60% and a pH value between 2.8 and 3.6, hydrogen bonds and hydrophobic interactions bind the individual pectin chains together. These bonds form as water is bound by sugar and forces pectin strands to stick together. These form a three-dimensional molecular net that creates the macromolecular gel. The gelling-mechanism is called a low-water-activity gel or sugar-acid-pectin gel.{{Citation needed|date=July 2018}}

While low-methoxy pectins need calcium to form a gel, they can do so at lower soluble solids and higher pH than high-methoxy pectins. Normally low-methoxy pectins form gels with a range of pH from 2.6 to 7.0 and with a soluble solids content between 10 and 70%.{{Citation needed|date=July 2018}}

To prepare a pectin-gel, the ingredients are heated, dissolving the pectin. Upon cooling below gelling temperature, a gel starts to form. If gel formation is too strong, syneresis or a granular texture are the result, while weak gelling leads to excessively soft gels.{{Citation needed|date=July 2018}}

High-ester pectins set at higher temperatures than low-ester pectins. However, gelling reactions with calcium increase as the degree of esterification falls. Similarly, lower pH-values or higher soluble solids (normally sugars) increase gelling speeds. Suitable pectins can therefore be selected for jams and jellies, or for higher-sugar confectionery jellies.{{Citation needed|date=July 2018}}

=== Pectinase === {{Main|Pectinase}} Pectinase is a group of enzymes that break down pectin. Pectin contributes to cell adhesion and wall rigidity; pectinases thereby play a role in softening plant tissues when hydrolyzing the glycosidic bonds in pectin. Pectinase occurs naturally in many microorganisms, including bacteria and fungi, and is also produced by plants as part of normal growth, fruit ripening and plant decay processes.<ref name="Barrera Pectin Review" />

Industrially, pectinase is widely used in the food industry to clarify fruit juices and wines, enhance juice extraction, and improve the texture of fruit-based products. It is also applied in textile processing, paper production, and wastewater treatment due to its ability to break down plant-derived materials efficiently.

== Production == The main raw materials for pectin production are dried citrus peels (85%) or apple pomace (14%), both by-products of juice production. Pomace from sugar beets is also used to a small extent (0.5%).<ref>{{Cite journal |last1=Belkheiri |first1=Anissa |last2=Forouhar |first2=Ali |last3=Ursu |first3=Alina Violeta |last4=Dubessay |first4=Pascal |last5=Pierre |first5=Guillaume |last6=Delattre |first6=Cedric |last7=Djelveh |first7=Gholamreza |last8=Abdelkafi |first8=Slim |last9=Hamdami |first9=Nasser |last10=Michaud |first10=Philippe |date=2021-07-18 |title=Extraction, Characterization, and Applications of Pectins from Plant By-Products |url= |journal=Applied Sciences |language=en |volume=11 |issue=14 |page=6596 |doi=10.3390/app11146596 |doi-access=free |issn=2076-3417 }}</ref>

The conventional pectin production method uses hot acidified water extraction, followed by filtration, alcohol precipitation, washing, and drying. This process is robust and established at large scale, but requires significant amounts of mineral acid and organic solvents and may cause partial degradation of the polymer structure (protopectin loses some of its branching).

Alternative "green" extraction methods have been developed to address these limitations. Such approaches aim to improve yield and functionality while reducing chemical and energy inputs. Although many of these methods remain at laboratory or pilot scale, they are the subject of ongoing research into sustainable pectin production.<ref>{{Cite journal |last1=Riyamol |last2=Gada Chengaiyan |first2=Jeevitha |last3=Rana |first3=Sandeep Singh |last4=Ahmad |first4=Faraz |last5=Haque |first5=Shafiul |last6=Capanoglu |first6=Esra |date=2023-12-12 |title=Recent Advances in the Extraction of Pectin from Various Sources and Industrial Applications |journal=ACS Omega |language=en |volume=8 |issue=49 |pages=46309–46324 |doi=10.1021/acsomega.3c04010 |doi-access=free|issn=2470-1343 |pmc=10723649 |pmid=38107881}}</ref>

=== Conventional solvent extraction method === Conventional pectin extraction from plant materials such as citrus peels and apple pomace involves the following steps:<ref>{{Cite journal |last1=Chandel |first1=Vinay |last2=Biswas |first2=Deblina |last3=Roy |first3=Swarup |last4=Vaidya |first4=Devina |last5=Verma |first5=Anil |last6=Gupta |first6=Anil |date=2022-09-02 |title=Current Advancements in Pectin: Extraction, Properties and Multifunctional Applications |journal=Foods |language=en |volume=11 |issue=17 |page=2683 |doi=10.3390/foods11172683 |doi-access=free |issn=2304-8158 |pmc=9455162 |pmid=36076865}}</ref>

* '''Pretreatment:''' washing, chopping, or drying the plant material to remove impurities and increase surface area. * '''Acid extraction:''' heating the material in dilute acid (usually mineral or organic) to solubilize the pectin. * '''Separation:''' removing solid residues by filtration or centrifugation. * '''Precipitation:''' adding alcohol (ethanol or isopropanol) to recover pectin from the solution. * '''Drying:''' collecting and drying the pectin to obtain a powder. * '''Optional modifications:''' adjusting the chemical properties (e.g., de-esterification) to achieve specific functional characteristics.

=== Green extraction methods ===

* '''Enzyme-assisted extraction (EAE)''' — uses pectinases, cellulases or hemicellulases to release pectin at milder pH/temperature; can increase yield and preserve certain side chains, but enzyme selectivity matters. Often combined with ultrasound or microwaves.<ref>{{Cite journal |last1=Bosch |first1=Ryan |last2=Malgas |first2=Samkelo |date=December 2023 |title=Ultrasound-assisted enzymatic extraction of orange peel pectin and its characterisation |url=https://academic.oup.com/ijfst/article/58/12/6784/7807186 |journal=International Journal of Food Science & Technology |language=en |volume=58 |issue=12 |pages=6784–6793 |doi=10.1111/ijfs.16646 |issn=0950-5423|hdl=2263/96249 |hdl-access=free }}</ref> * '''Ultrasound-assisted extraction (UAE)''' — cavitations support mass transfer; reduces time and temperature. Can be combined with enzymes (UA-EAE) or microwaves.<ref>{{Cite journal |last1=Lasunon |first1=Patareeya |last2=Sengkhamparn |first2=Nipaporn |date=2022-02-09 |title=Effect of Ultrasound-Assisted, Microwave-Assisted and Ultrasound-Microwave-Assisted Extraction on Pectin Extraction from Industrial Tomato Waste |journal=Molecules |language=en |volume=27 |issue=4 |page=1157 |doi=10.3390/molecules27041157 |doi-access=free |issn=1420-3049 |pmc=8877420 |pmid=35208946}}</ref> * '''Microwave-assisted extraction (MAE)''' and '''microwave-hydrothermal (MAHE)''' — fast heating, short extraction times; can give high yields but needs optimization to avoid degradation.<ref>{{Cite journal |last1=Benmebarek |first1=Imed E. |last2=Gonzalez-Serrano |first2=Diego J. |last3=Aghababaei |first3=Fatemeh |last4=Ziogkas |first4=Dimitrios |last5=Garcia-Cruz |first5=Rosario |last6=Boukhari |first6=Abbas |last7=Moreno |first7=Andres |last8=Hadidi |first8=Milad |date=October 2024 |title=Optimizing the microwave-assisted hydrothermal extraction of pectin from tangerine by-product and its physicochemical, structural, and functional properties |journal=Food Chemistry: X |language=en |volume=23 |article-number=101615 |doi=10.1016/j.fochx.2024.101615 |pmc=11637218 |pmid=39669899}}</ref>

==Uses== The main use for pectin is as a gelling agent, thickening agent and stabiliser in food.<ref name="Han-2020">{{cite web|url=https://foodadditives.net/thickeners/pectin/| vauthors = Han J |title=What is Pectin (E440)? Sources, Types, Uses, and Benefits|date=13 June 2020|access-date=7 April 2024|archive-date=27 September 2023|archive-url=https://web.archive.org/web/20230927090934/https://foodadditives.net/thickeners/pectin/|url-status=live}}</ref>

In some countries, pectin is also available as a solution or an extract, or as a blended powder, for home jam making.{{citation needed|date=April 2024}}

The classical application is giving the jelly-like consistency to jams or marmalades, which would otherwise be sweet juices.<ref name="Surolia-2024">{{cite book|doi=10.1007/978-3-031-46046-3_13 |chapter=Pectin—Structure, Specification, Production, Applications and various Emerging Sources: A Review |title=Sustainable Food Systems (Volume II) |series=World Sustainability Series |date=2024 |pages=267–282 |isbn=978-3-031-46045-6 | vauthors = Surolia R, Singh A }}</ref> Pectin also reduces syneresis in jams and marmalades and increases the gel strength of low-calorie jams. For household use, pectin is an ingredient in gelling sugar (also known as "jam sugar") where it is diluted to the right concentration with sugar and some citric acid to adjust pH.{{citation needed|date=April 2024}}

For various food applications, different kinds of pectins can be distinguished by their properties, such as acidity, degree of esterification, relative number of methoxyl groups in the molecules, etc. For instance, the term "high methoxyl" refers to pectins that have a large proportion of the carboxyl groups in the pectin molecule that are esterified with methanol, compared to low methoxyl pectins:<ref name="Surolia-2024"/><ref name="Kontogiorgos V-2020">{{cite book|doi=10.1007/978-3-030-53421-9 |title=Pectin: Technological and Physiological Properties |date=2020 |isbn=978-3-030-53420-2 | veditors = Kontogiorgos V }}</ref><ref name="Endress-2011">{{cite book|doi=10.1039/9781849733519-00210|date=17 August 2011 |chapter=Pectins: Production, Properties and Applications |title=Renewable Resources for Functional Polymers and Biomaterials |pages=210–260 |isbn=978-1-84973-245-1 | vauthors = Endress H }}</ref> * high methoxyl pectins are defined as those with a degree of esterification equal to or above 50, are typically used in traditional jam and jelly making;<ref name="UniPECTINE">{{cite web|url=https://www.cargill.com/doc/1432231523066/cargill-emea-unipectine-brochure.pdf|title=UniPECTINE|access-date=7 April 2024|archive-date=7 April 2024|archive-url=https://web.archive.org/web/20240407124532/https://www.cargill.com/doc/1432231523066/cargill-emea-unipectine-brochure.pdf|url-status=live}}</ref><ref name="Yang-2020">{{cite book|doi=10.1007/978-3-030-53421-9_1|isbn=978-3-030-53421-9|date=2 October 2020 |chapter=Biosynthesis, Localisation, and Function of Pectins in Plants |title=Pectin: Technological and Physiological Properties |pages=1–15 | vauthors = Yang Y, Anderson CT }}</ref><ref name="Han-2020"/> such pectins require high sugar concentrations and acidic conditions to form gels, and provide a smooth texture and suitable to be used in bakery fillings and confectionery applications;<ref name="Han-2020"/><ref name="Endress-2011"/><ref name="Sultana-2023">{{cite journal |vauthors=Sultana N |title=Biological Properties and Biomedical Applications of Pectin and Pectin-Based Composites: A Review |journal=Molecules |volume=28 |issue=24 |date=December 2023 |page=7974 |pmid=38138464 |pmc=10745545 |doi=10.3390/molecules28247974 |doi-access=free}}</ref> * low methoxyl pectins have a degree of esterification of less than 50,<ref name="Endress-2011"/><ref name="Han-2020"/> can be either amidated or non-amidated: the percentage level of substitution of the amide group, defined as the degree of amidation, defines the efficacy of a pectin;<ref name="Han-2020"/> low methoxyl pectins can provide a range of textures and rheological properties, depending on the calcium concentration and the calcium reactivity of the pectin chosen<ref name="Said-2023">{{cite journal |vauthors=Said NS, Olawuyi IF, Lee WY |title=Pectin Hydrogels: Gel-Forming Behaviors, Mechanisms, and Food Applications |journal=Gels |volume=9 |issue=9 |date=September 2023 |page=732 |pmid=37754413 |pmc=10530747 |doi=10.3390/gels9090732 |doi-access=free}}</ref>—amidated low methoxyl pectins are generally thermoreversible, meaning they can form gels that can melt and reform, whereas non-amidated low methoxyl pectins can form thermostable gels that withstand high temperatures;<ref name="Said-2023" /> these properties make low methoxyl pectins suitable for low sugar and sugar-free applications, dairy products, and stabilizing acidic protein drinks.<ref name="UniPECTINE"/><ref name="Kontogiorgos V-2020"/><ref name="Han-2020"/>

For conventional jams and marmalades that contain above 60% sugar and soluble fruit solids, high-ester (high methoxyl) pectins are used. With low-ester (low methoxyl) pectins and amidated pectins, less sugar is needed, so that diet products can be made. Water extract of aiyu seeds is traditionally used in Taiwan to make aiyu jelly, where the extract gels without heating due to low-ester pectins from the seeds and the bivalent cations from the water.<ref name="Liang-2012"/>

Pectin is used in confectionery jellies to give a good gel structure, a clean bite and to confer a good flavour release. Pectin can also be used to stabilise acidic protein drinks, such as drinking yogurt, to improve the mouth-feel and the pulp stability in juice based drinks and as a fat substitute in baked goods.<ref name="UniPECTINE"/><ref name="May-1990" >{{cite journal | vauthors = May CD | year = 1990 | title = Industrial pectins: Sources, production and applications | journal = Carbohydrate Polymers | volume = 12 | issue = 1| pages = 79–99 | doi = 10.1016/0144-8617(90)90105-2 }}</ref>

Typical levels of pectin used as a food additive are between 0.5 and 1.0% – this is about the same amount of pectin as in fresh fruit.<ref name="Thakur-1997">{{cite journal | vauthors = Thakur BR, Singh RK, Handa AK | title = Chemistry and uses of pectin--a review | journal = Critical Reviews in Food Science and Nutrition | volume = 37 | issue = 1 | pages = 47–73 | date = February 1997 | pmid = 9067088 | doi = 10.1080/10408399709527767 }}</ref>

In medicine, pectin increases viscosity and volume of stool so that it is used against constipation and diarrhea. It was one of the main ingredients used in Kaopectate – a medication to combat diarrhea – along with kaolinite. It has been used in gentle heavy metal removal from biological systems.<ref name="Zhao-2008">{{cite journal | vauthors = Zhao ZY, Liang L, Fan X, Yu Z, Hotchkiss AT, Wilk BJ, Eliaz I | title = The role of modified citrus pectin as an effective chelator of lead in children hospitalized with toxic lead levels | journal = Alternative Therapies in Health and Medicine | volume = 14 | issue = 4 | pages = 34–38 | date = 2008 | pmid = 18616067 | doi = | url = }}</ref> Pectin is also used in throat lozenges as a demulcent.<ref>{{Cite web |last=McMillen |first=Matt |date=6 November 2024 |title=Pectin: Uses and Risks |url=https://www.webmd.com/vitamins-and-supplements/pectin-uses-and-risks |url-status=live |archive-url=https://web.archive.org/web/20251118035619/https://www.webmd.com/vitamins-and-supplements/pectin-uses-and-risks |archive-date=18 November 2025 |access-date=9 February 2026 |website=WebMD}}</ref>

In cosmetic products, pectin acts as a stabiliser. Pectin is also used in wound healing preparations and speciality medical adhesives, such as colostomy devices.{{Citation needed|date=July 2018}}

Sriamornsak<ref name="Sriamornsak-2011">{{cite journal | vauthors = Sriamornsak P | title = Application of pectin in oral drug delivery | journal = Expert Opinion on Drug Delivery | volume = 8 | issue = 8 | pages = 1009–1023 | date = August 2011 | pmid = 21564000 | doi = 10.1517/17425247.2011.584867 | s2cid = 25595142 }}</ref> revealed that pectin could be used in various oral drug delivery platforms, e.g., controlled release systems, gastro-retentive systems, colon-specific delivery systems and mucoadhesive delivery systems, according to its intoxicity and low cost. It was found that pectin from different sources provides different gelling abilities, due to variations in molecular size and chemical composition. Like other natural polymers, a major problem with pectin is inconsistency in reproducibility between samples, which may result in poor reproducibility in drug delivery characteristics.{{Citation needed|date=July 2018}}

In ruminant nutrition, depending on the extent of lignification of the cell wall, pectin is up to 90% digestible by bacterial enzymes. Ruminant nutritionists recommend that the digestibility and energy concentration in forages be improved by increasing pectin concentration in the forage.{{Citation needed|date = July 2024}}

In cigars, pectin is considered an excellent substitute for vegetable glue and many cigar smokers and collectors use pectin for repairing damaged tobacco leaves on their cigars.{{Citation needed|date = July 2024}}

Yablokov ''et al.'', writing in ''Chernobyl: Consequences of the Catastrophe for People and the Environment'', quote research conducted by the Ukrainian Center of Radiation Medicine and the Belarusian Institute of Radiation Medicine and Endocrinology, concluded, regarding pectin's radioprotective effects, that "adding pectin preparations to the food of inhabitants of the Chernobyl-contaminated regions promotes an effective excretion of incorporated radionuclides" such as cesium-137. The authors reported on the positive results of using pectin food additive preparations in a number of clinical studies conducted on children in severely polluted areas, with up to 50% improvement over control groups.<ref name="Nesterenko-2009">{{cite journal | vauthors = Nesterenko VB, Nesterenko AV | title = 13. Decorporation of Chernobyl radionuclides | journal = Annals of the New York Academy of Sciences | volume = 1181 | issue = 1| pages = 303–310 | date = November 2009 | pmid = 20002057 | doi = 10.1111/j.1749-6632.2009.04838.x | bibcode = 2009NYASA1181..303N | url = https://books.google.com/books?id=g34tNlYOB3AC&pg=PA304 | isbn = 978-1-57331-757-3 | url-access = subscription }}</ref> During the Second World War, Allied pilots were provided with maps printed on silk, for navigation in escape and evasion efforts. The printing process at first proved nearly impossible because the several layers of ink immediately ran, blurring outlines and rendering place names illegible until the inventor of the maps, Clayton Hutton, mixed a little pectin with the ink and at once the pectin coagulated the ink and prevented it from running, allowing small topographic features to be clearly visible.<ref name="www.escape-maps.com">{{Cite web|url=http://www.escape-maps.com/escape_maps/history_of_wwii_british_cloth_escape_maps.htm#_edn24|title=history of wwii british cloth escape maps|website=www.escape-maps.com|access-date=29 June 2019|archive-date=25 June 2019|archive-url=https://web.archive.org/web/20190625005526/http://www.escape-maps.com/escape_maps/history_of_wwii_british_cloth_escape_maps.htm#_edn24|url-status=live}}</ref>

==Legal status== At the Joint FAO/WHO Expert Committee Report on Food Additives and in the European Union, no numerical acceptable daily intake (ADI) has been set, as pectin is considered safe.<ref name="FAO/WHO Expert Committee on Food Additives">{{cite web |title=Joint FAO/WHO Expert Committee on Food Additives | url = http://www.who.int/ipcs/food/jecfa/en/ |website=World Health Organization | archive-url = https://web.archive.org/web/20040708001807/http://www.who.int/ipcs/food/jecfa/en/ | access-date = 16 July 2012 | archive-date = 8 July 2004 }}</ref>

The European Union (EU) has not set a daily intake limit for two types of pectin, known as E440(i) and Amidated Pectin E440(ii). The EU has established purity standards for these additives in the EU Commission Regulation (EU)/231/2012. Pectin can be used as needed in most food categories, a concept referred to as "quantum satis".<ref name="Commission Regulation">{{cite web | url=https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32011R1130 | title=Commission Regulation (EU) No 1130/2011 of 11 November 2011 amending Annex III to Regulation (EC) No 1333/2008 of the European Parliament and of the Council on food additives by establishing a Union list of food additives approved for use in food additives, food enzymes, food flavourings and nutrients Text with EEA relevance | access-date=7 April 2024 | archive-date=11 December 2023 | archive-url=https://web.archive.org/web/20231211105626/http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX%3A32011R1130 | url-status=live }}</ref> The European Food Safety Authority (EFSA) conducted a re-evaluation of Pectin E440(i) and Amidated Pectin E440(ii) in 2017. The EFSA concluded that the use of these food additives poses no safety concern for the general population. Furthermore, the agency stated that it is not necessary to establish a numerical value for the Acceptable Daily Intake (ADI).<ref name="Mortensen-2017">{{cite journal | doi=10.2903/j.efsa.2017.4866 | title=Re-evaluation of pectin (E 440i) and amidated pectin (E 440ii) as food additives | journal=EFSA Journal | volume=15 | issue=7 | pages=e04866 | pmid=32625540 | pmc=7010145 | vauthors=Mortensen A, Aguilar F, Crebelli R, Di Domenico A, Dusemund B, Frutos MJ, Galtier P, Gott D, Gundert-Remy U, Lambré C, Leblanc J, Lindtner O, Moldeus P, Mosesso P, Oskarsson A, Parent-Massin D, Stankovic I, Waalkens-Berendsen I, Wright M, Younes M, Tobback P, Ioannidou S, Tasiopoulou S, Woutersen RA, Woutersen RA | url=https://www.efsa.europa.eu/en/efsajournal/pub/4866 | date=6 July 2017 | access-date=7 April 2024 | archive-date=21 January 2022 | archive-url=https://web.archive.org/web/20220121075034/https://www.efsa.europa.eu/en/efsajournal/pub/4866 | url-status=live }}</ref><ref name="EFSA Panel on Food Additives and Flavourings (FAF)-2021">{{cite journal | doi=10.2903/j.efsa.2021.6387 | url=https://www.efsa.europa.eu/en/efsajournal/pub/6387 | title=Opinion on the re-evaluation of pectin (E 440i) and amidated pectin (E 440ii) as food additives in foods for infants below 16 weeks of age and follow-up of their re-evaluation as food additives for uses in foods for all population groups {{pipe}} EFSA | date=29 January 2021 | pmid=33537069 | author1=EFSA Panel on Food Additives and Flavourings (FAF) | journal=EFSA Journal | volume=19 | issue=1 | pages=e06387 | pmc=7845505 | hdl=11368/2979399 | access-date=7 April 2024 | archive-date=21 January 2022 | archive-url=https://web.archive.org/web/20220121064700/https://www.efsa.europa.eu/en/efsajournal/pub/6387 | url-status=live }}</ref>

In the United States, pectin is generally recognised as safe for human consumption.{{citation needed|date=April 2024}}

In the International Numbering System (INS), pectin has the number 440. In Europe, pectins are differentiated into the E numbers E440(i) for non-amidated pectins and E440(ii) for amidated pectins. There are specifications in all national and international legislation defining its quality and regulating its use.{{citation needed|date=April 2024}}

==History== Pectin was first isolated and described in 1825 by Henri Braconnot, though the action of pectin to make jams and marmalades was known long before. To obtain well-set jams from fruits that had little or only poor quality pectin, pectin-rich fruits or their extracts were mixed into the recipe.{{Citation needed|date = July 2024}}

During the Industrial Revolution, the makers of fruit preserves turned to producers of apple juice to obtain dried apple pomace that was cooked to extract pectin. Later, in the 1920s and 1930s, factories were built that commercially extracted pectin from dried apple pomace, and later citrus peel, in regions that produced apple juice in both the US and Europe.{{Citation needed|date = July 2024}}

Pectin was first sold as a liquid extract, but is now most often used as dried powder, which is easier than a liquid to store and handle.<ref name="International Pectin Producers Association">{{cite web | url = http://www.ippa.info | title = International Pectin Producers Association | archive-url = https://web.archive.org/web/20220211200148/https://ippa.info/ | archive-date=11 February 2022 | access-date = 13 June 2007 }}</ref>

==See also== {{Portal|Food}} * Fruit snacks

== References == {{CC-notice|cc=by4|url=https://www.sciencedirect.com/science/article/pii/S0144861724010208|author=Luna Barrera-Chamorro, África Fernandez-Prior, Fernando Rivero-Pino and Sergio Montserrat-de la Paz}}

{{Reflist|30em}}

==External links== * [http://www.codexalimentarius.net/gsfaonline/additives/details.html?id=21 Codex General Standard for Food Additives (GSFA) Online Database; A list of permitted uses of pectin, further link to the JECFA (...) specification of pectin.] * [https://web.archive.org/web/20080309150734/http://eur-lex.europa.eu/LexUriServ/site/en/consleg/1995/L/01995L0002-20031120-en.pdf European parliament and council directive No 95/2/EC of 20 February 1995 on food additives other than colours and sweeteners; EU-Directive that lists the foods, pectin may be used in.] Note: The link points to a "consleg"-version of the directive, that may not include the very latest changes. The Directive will be replaced by a new Regulation for food additives in the next few years. * [http://www.certohealth.co.uk/health.html Certo Health: Information on reported health benefits of apple pectin, (UK).]

{{Apples|state=collapsed}} {{Carbohydrates}} {{Antidiarrheals, intestinal anti-inflammatory and anti-infective agents}} {{Authority control}}

Category:Dietary fiber Category:Polysaccharides Category:Food additives Category:Food science Category:Natural gums Category:Edible thickening agents Category:Demulcents Category:Food stabilizers Category:E-number additives