Editing Pectin (section)

== Biology ==
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 [[enzyme]]s [[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 [[Petiole (botany)|petiole]]s of [[deciduous]] plants at leaf fall.{{Citation needed|date = March 2015}}

Pectin is a natural part of the human [[wikt:diet|diet]], but does not contribute significantly to [[wikt:nutrition|nutrition]]. 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 [[NOD mice|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 [[Large intestine|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>

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>

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 | 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 | date = May 2012 | pmid = 22190137 | doi = 10.1038/ejcn.2011.208 | 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 |url=http://www.journal.su.ac.th/index.php/suij/article/viewFile/48/48 | vauthors = Sriamornsak P |title=Chemistry of Pectin and its Pharmaceutical Uses: A Review |journal=Silpakorn University International Journal |volume=3 |issue=1–2 |year=2003 |page=206 |access-date=23 August 2007 |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 |url-status=dead }}</ref> In the large intestine and colon, microorganisms degrade pectin and liberate [[short-chain fatty acid]]s that have a positive [[Prebiotic (nutrition)|prebiotic]] effect.<ref name="Gómez-2014">{{cite journal | vauthors = Gómez B, Gullón B, Remoroza C, Schols HA, Parajó JC, Alonso JL | 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 | date = October 2014 | pmid = 25207862 | doi = 10.1021/jf503475b | bibcode = 2014JAFC...62.9769G }}</ref>