Editing Kelp (section)

== Uses ==
{{Main|Seaweed farming|l1=Kelp farming}}
{{nutritional value | name=Seaweed, kelp, raw
| kJ=180
| protein=1.68 g
| fat=0.56 g
| carbs=9.57 g
| fiber=1.3 g
| sugars=0.6
| calcium_mg=168
| iron_mg=2.85
| magnesium_mg=121
| phosphorus_mg=42
| potassium_mg=89
| sodium_mg=233
| zinc_mg=1.23
| manganese_mg=0.2
| vitC_mg=3
| thiamin_mg=0.05
| riboflavin_mg=0.15
| niacin_mg=0.47
| pantothenic_mg=0.642
| folate_ug=180
| vitE_mg=0.87
| vitK_ug=66
| source_usda = 1
| note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/168457/nutrients Link to USDA Database entry]
}}

Giant kelp can be harvested fairly easily because of its surface canopy and growth habit of staying in deeper water.

Kelp ash is rich in [[iodine]] and [[alkali]]. In great amount, kelp ash can be used in [[soap]] and [[glass]] production. Until the [[Leblanc process]] was commercialized in the early 19th century, burning of kelp in Scotland was one of the principal industrial sources of soda ash (predominantly [[sodium carbonate]]).<ref name="Clow 52">{{cite book |last1=Clow |first1=Archibald |last2=Clow |first2=Nan L. |date=1952 |title=Chemical Revolution |publisher=Ayer Co Pub |pages=[https://archive.org/details/chemicalrevoluti0000clow/page/65 65–90] |isbn=978-0-8369-1909-7 |oclc=243798097 |url=https://archive.org/details/chemicalrevoluti0000clow/page/65 }}</ref> Around 23 tons of seaweed was required to produce 1 ton of kelp ash. The kelp ash would consist of around 5% sodium carbonate.<ref>Jonathan Pereira, Fred B. Kilmer, The Elements of Materia Medica and Therapeutics, Volume 1, 1854, p. 558</ref>

Once the [[Leblanc Process]] became commercially viable in Britain during the 1820s, common salt replaced kelp ash as raw material for sodium carbonate. Though the price of kelp ash went into steep decline, seaweed remained the only commercial source of iodine. To supply the new industry in iodine synthesis, kelp ash production continued in some parts of West and North Scotland, North West Ireland and Guernsey. The species ''[[Saccharina latissima]]'' yielded the greatest amount of iodine (between 10 and 15 lbs per ton) and was most abundant in Guernsey. Iodine was extracted from kelp ash using a [[lixiviation]] process.<ref>Edward C. C. Stanford, Wentworth L. Scott,  ‘The Economic Applications of Seaweed’, February 14, 1862, Journal of the Royal Society of Arts, Vol 10, No. 482, 185-199</ref> As with sodium carbonate however, mineral sources eventually supplanted seaweed in iodine production.<ref>John J. McKetta Jr. Taylor & Francis,  Encyclopaedia of Chemical Processing and Design: Volume 27 - Hydrogen Cyanide to Ketones Dimethyl (Acetone), 1988, p. 283</ref>

[[Alginate]], a kelp-derived carbohydrate, is used to thicken products such as [[ice cream]], [[Jelly (fruit preserves)|jelly]], [[salad dressing]], and [[toothpaste]], as well as an ingredient in exotic [[dog food]] and in manufactured goods.<ref>{{cite book |last1=Brownlee |first1=Iain A. |chapter=Applications of Alginates in Food |date=2009 |title=Alginates: Biology and Applications |pages=211–228 |editor-last=Rehm |editor-first=Bernd H. A. |series=Microbiology Monographs |publisher=Springer Berlin Heidelberg |language=en |isbn=9783540926795 |chapter-url=https://www.researchgate.net/publication/225729229 |access-date=2019-01-25 |doi=10.1007/978-3-540-92679-5_9 |last2=Seal |first2=Chris J. |last3=Wilcox |first3=Matthew |last4=Dettmar |first4=Peter W. |last5=Pearson |first5=Jeff P.|volume=13 }}</ref><ref>{{Cite journal |last1=Uzunović |first1=Alija |last2=Mehmedagić |first2=Aida |last3=Lačević |first3=Amela |last4=Vranić |first4=Edina |date=2004-11-20 |title=Formulation ingredients for toothpastes and mouthwashes |journal=Bosnian Journal of Basic Medical Sciences |language=en-US |volume=4 |issue=4 |pages=51–58 |doi=10.17305/bjbms.2004.3362 |pmid=15628997 |pmc=7245492 |issn=1840-4812 |doi-access=free}}</ref><ref>{{Cite journal |last1=Rychen |first1=Guido |last2=Aquilina |first2=Gabriele |last3=Azimonti |first3=Giovanna |last4=Bampidis |first4=Vasileios |last5=Bastos |first5=Maria de Lourdes |last6=Bories |first6=Georges |last7=Chesson |first7=Andrew |last8=Cocconcelli |first8=Pier Sandro |last9=Flachowsky |first9=Gerhard |date=2017 |title=Safety and efficacy of sodium and potassium alginate for pets, other non food-producing animals and fish |journal=EFSA Journal |language=en |volume=15 |issue=7 |pages=e04945 |doi=10.2903/j.efsa.2017.4945 |pmid=32625597 |pmc=7009951 |issn=1831-4732 |doi-access=free}}</ref> Alginate powder is also used frequently in general dentistry and orthodontics for making impressions of the upper and lower arches.<ref>Powers, John M. Powers. Craig's Restorative Dental Materials, 12th Edition. C.V. Mosby, 022006. p. 270</ref> Kelp polysaccharides are used in skin care as gelling ingredients and because of the benefits provided by ''[[fucoidan]]''.{{citation needed|date=April 2023}}

[[Kombu]] (昆布 in Japanese, and 海带 in Chinese, ''[[Saccharina japonica]]'' and others), several Pacific species of kelp, is a very important ingredient in Chinese, Japanese, and Korean cuisines. Kombu is used to flavor broths and stews (especially ''[[dashi]]''), as a savory garnish (''tororo konbu'') for rice and other dishes, as a vegetable, and a primary ingredient in popular snacks (such as ''[[tsukudani]]''). Transparent sheets of kelp (''oboro konbu'') are used as an edible decorative wrapping for rice and other foods.<ref>Kazuko, Emi: ''Japanese Cooking'', p. 78, Hermes House, 2002, p. 78. {{ISBN|0-681-32327-2}}</ref>

Kombu can be used to soften beans during cooking, and to help convert indigestible sugars and thus reduce flatulence.<ref>Graimes, Nicola: ''The Best-Ever Vegetarian Cookbook'', [[Barnes & Noble]] Books, 1999, p. 59. {{ISBN|0-7607-1740-0}}</ref>

[[File:Morskaja-kapusta.jpg|thumb| ''[[Saccharina latissima]]'' in canned salad form]]

In Russia, especially in the [[Russian Far East]], and former Soviet Union countries several types of kelp are of commercial importance: ''[[Saccharina latissima]]'', ''[[Laminaria digitata]]'', ''[[Saccharina japonica]]''. Known locally as "Sea Cabbage" (Морская капуста in Russian), it comes in retail trade in dried or frozen, as well as in canned form and used as filler in different types of salads, soups and pastries.<ref>{{Cite web|title=Features of the Far Eastern cuisine|url=https://www.eastrussia.ru/eng/features-of-the-far-eastern-cuisine/|access-date=2021-01-14|website=www.eastrussia.ru|archive-date=2021-01-16|archive-url=https://web.archive.org/web/20210116160637/https://www.eastrussia.ru//eng/features-of-the-far-eastern-cuisine/|url-status=dead}}</ref>

Because of its high concentration of iodine, brown kelp (''[[Laminaria]]'') has been used to treat [[goiter]], an enlargement of the thyroid gland caused by a lack of iodine, since medieval times.<ref>[http://newswise.com/articles/view/541835/ Iodine Helps Kelp Fight Free Radicals and May Aid Humans, Too] Newswise, Retrieved on July 8, 2008.</ref> An intake of roughly 150 micrograms of iodine per day is beneficial for preventing hypothyroidism. Overconsumption can lead to kelp-induced [[thyrotoxicosis]].<ref>{{cite journal |last1=Leung |first1=Angela M. |last2=Braverman |first2=Lewis E. |title=Consequences of excess iodine |url=https://doi.org/10.1038/nrendo.2013.251 |journal=Nature Reviews Endocrinology |pages=136–142 |language=en |doi=10.1038/nrendo.2013.251 |date=March 2014|volume=10 |issue=3 |pmid=24342882 |pmc=3976240 }}</ref>

In 2010, researchers found that [[alginate]], the [[soluble fibre]] substance in sea kelp, was better at preventing fat absorption than most over-the-counter slimming treatments in laboratory trials.  As a food additive, it may be used to reduce fat absorption and thus obesity.<ref>{{cite web|url=http://news.sky.com/skynews/Home/UK-News/Seaweed-May-Fight-Obesity-Could-Alginates-Be-The-Answer-To-A-Dieters-Prayer/Article/201003415579083 |title=Is Seaweed The Answer To A Dieter's Prayer? |access-date=March 23, 2010 |date=March 22, 2010 |publisher=Sky News |url-status=dead |archive-url=https://web.archive.org/web/20100325103205/http://news.sky.com/skynews/Home/UK-News/Seaweed-May-Fight-Obesity-Could-Alginates-Be-The-Answer-To-A-Dieters-Prayer/Article/201003415579083 |archive-date=March 25, 2010 }}</ref> Kelp in its natural form has not yet been demonstrated to have such effects.

Kelp's rich iron content can help prevent iron deficiency.<ref>{{cite journal |last1=Miller |first1=Eric P. |last2=Auerbach |first2=Hendrik |last3=Schünemann |first3=Volker |last4=Tymon |first4=Teresa |last5=Carrano |first5=Carl J. |title=Surface binding, localization and storage of iron in the giant kelp Macrocystis pyrifera |journal=Metallomics |date=20 April 2016 |volume=8 |issue=4 |pages=403–411 |doi=10.1039/C6MT00027D |pmid=27009567 |language=en |issn=1756-591X|doi-access=free }}</ref>

===Commercial production===
Commercial production of kelp harvested from its natural habitat has taken place in Japan for over a century. Many countries today produce and consume laminaria products; the largest producer is China. ''[[Laminaria japonica]]'', the important commercial seaweed, was first introduced into China in the late 1920s from Hokkaido, Japan. Yet [[mariculture]] of this alga on a very large commercial scale was realized in China only in the 1950s. Between the 1950s and the 1980s, kelp production in China increased from about 60 to over 250,000 dry weight metric tons annually.<!--
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