Editing Corn syrup

{{Globalize|1=article|2=United States|date=January 2023}}
{{Infobox food
| image = Corn syrup.jpg
| cookbook = Corn Syrup
}}{{Short description|Syrup made from corn used as food additive}}
{{Use dmy dates|date=September 2018}}
[[File:Corn syrup tank car.jpg|alt=|thumb|A [[Tank car|railroad tank car]] carrying corn syrup]]

'''Corn syrup''' is a food [[syrup]] which is made from the [[starch]] of corn/[[maize]] and contains varying amounts of sugars: [[glucose]], [[maltose]] and higher [[oligosaccharide]]s, depending on the grade. Corn syrup is used in foods to soften [[Mouthfeel|texture]], add volume, prevent [[crystallization]] of sugar, and enhance flavor. Most [[table syrup]]s are typically based with corn syrup. It can be processed into [[high-fructose corn syrup]] (HFCS) by using the enzyme [[xylose isomerase|D-xylose isomerase]] to convert a large proportion of its glucose into sweeter [[fructose]].

The more general term [[glucose syrup]] is often used synonymously with corn syrup, since glucose syrup in the United States is most commonly made from [[corn starch]].<ref>Structure of the world starch market, European Commission - Directorate Agricultural and Rural development, Evaluation of the Community Policy for Starch and Starch Products, Final report 2002, Chapter 1, page 3 [https://web.archive.org/web/20110516230603/http://ec.europa.eu/agriculture/eval/reports/amidon/chap1.pdf]</ref><ref>{{cite web |url=http://www.sugar.org/consumers/sweet_by_nature.asp?id=277 |title=Sugar Association Alternative Carbohydrate Sweeteners |url-status=dead |archive-url=https://web.archive.org/web/20060923020810/http://www.sugar.org/consumers/sweet_by_nature.asp?id=277 |archive-date=23 September 2006 }}</ref> Technically, glucose syrup is any liquid starch [[hydrolysis|hydrolysate]] of mono-, di-, and higher-[[saccharide]]s and can be made from any source of starch: wheat, [[tapioca]] and potatoes are the most common other sources.<ref>[http://www.starch.dk/isi/starch/tm33www-wheat.htm Wheat starch, Application, International Starch Institute Denmark]</ref><ref>[http://webapp.ciat.cgiar.org/asia_cassava/pdf/proceedings_workshop_00/593.pdf Global casave outlook; Guy Henry, Andrew Westby; 2007; page 600] {{webarchive|url=https://web.archive.org/web/20120405043608/http://webapp.ciat.cgiar.org/asia_cassava/pdf/proceedings_workshop_00/593.pdf |date=5 April 2012 }}</ref><ref>{{cite web|title=International Starch Association Starch and Glucose Glossary|url=http://www.starch.dk/isi/starch/glosary.htm|url-status=dead|archive-url=https://web.archive.org/web/20020716053905/http://www.starch.dk/isi/starch/glosary.htm|archive-date=July 16, 2002}}</ref>

== Commercial preparation ==
Historically, corn syrup was produced by combining corn starch with dilute [[hydrochloric acid]], and then heating the mixture under pressure. The process was invented by the German chemist [[Gottlieb Kirchhoff]] in 1811. Currently, corn syrup is obtained through a multi-step [[bioprocess]]. First, the [[enzyme]] α-[[amylase]] is added to a mixture of corn starch and water. α-amylase is secreted by various species of the [[bacteria|bacterium]] genus ''[[Bacillus]]'' and is isolated from the liquid in which the bacteria were grown. The enzyme breaks down the starch into [[oligosaccharide]]s, which are then broken into glucose molecules by adding the enzyme [[glucoamylase]], known also as "γ-amylase". Glucoamylase is secreted by various species of the [[fungus]] ''[[Aspergillus]]''; the enzyme is isolated from the liquid in which the fungus is grown. The glucose can then be transformed into fructose by passing the glucose through a column that is loaded with the enzyme [[Xylose isomerase|D-xylose isomerase]], an enzyme that is isolated from the growth medium of any of several bacteria.<ref>Martin Chaplin and Christopher Bucke, ''Enzyme Technology'' (Cambridge, England: Cambridge University Press, 1990), pages 146-154. Available on-line at: [https://web.archive.org/web/20121027003434/http://www.lsbu.ac.uk/water/enztech/ London South Bank University: Enzyme Technology]. See "Chapter 4: The large-scale use of enzymes in solution", sections:

* [https://web.archive.org/web/20121231050715/http://www.lsbu.ac.uk/water/enztech/starch.html The use of enzymes in starch hydrolysis]
* [https://web.archive.org/web/20130612192915/http://www.lsbu.ac.uk/water/enztech/glucose.html Production of glucose syrup]</ref>

Corn syrup is produced from number 2 yellow dent corn.<ref>"Dent corn" (''Zea mays var. indentata'') is so called because the tops of its kernels are slightly indented. See [http://www.merriam-webster.com/dictionary/dent+corn Merriam-Webster dictionary].</ref> When [[wet-milling|wet milled]], about 2.3 litres of corn are required to yield an average of 947g of starch, to produce 1&nbsp;kg of glucose syrup. A [[bushel]] (25&nbsp;kg) of corn will yield an average of 31.5 pounds (14.3&nbsp;kg) of starch, which in turn will yield about 33.3 pounds (15.1&nbsp;kg) of syrup. Thus, it takes about 2,300 litres of corn to produce a [[tonne]] of glucose syrup, or 60 bushels (1524&nbsp;kg) of corn to produce one [[short ton]].<ref name="hydrolysis">{{cite web|title=Enzymatic starch hydrolysis: background|url=http://www.bpe.wur.nl/UK/Research/Dissertations/Enzymatic+starch+hydrolysis/Enzymatic+starch+hydrolysis+background/|url-status=dead|archive-url=https://web.archive.org/web/20081004055213/http://www.bpe.wur.nl/UK/Research/Dissertations/Enzymatic+starch+hydrolysis/Enzymatic+starch+hydrolysis+background/|archive-date=October 4, 2008}}</ref><ref>Trends in U.S. production and use of glucose syrup and dextrose, 1965-1990, and prospects for the future - U.S. Dept. of Agriculture, Economic Research Service report [https://archive.today/20120708093106/http://findarticles.com/p/articles/mi_m3796/is_1991_Sept/ai_11917704]</ref>

The viscosity and sweetness of the syrup depends on the extent to which the hydrolysis reaction has been carried out. To distinguish different grades of syrup, they are rated according to their [[dextrose equivalent]] (DE). Most commercially available corn syrups are approximately 1/3 glucose by weight.{{Cn|date=January 2021}}

Two common commercial corn syrup products are light and dark corn syrup.<ref name="KFAQ">{{cite web|title=Karo Syrup - FAQ|url=http://www.karosyrup.com/faq.html|website=Karo|publisher=ACH Food Companies, Inc.|access-date=15 May 2015|archive-date=11 May 2015|archive-url=https://web.archive.org/web/20150511213811/http://www.karosyrup.com/faq.html|url-status=dead}}</ref>
*''Light corn syrup'' is corn syrup seasoned with [[vanilla]] flavor and salt.  It is a nearly clear color.
*''Dark corn syrup'' is a combination of corn syrup and [[refiner's syrup]], caramel color and flavor, salt, and the preservative sodium benzoate. Its color is dark brown.

== Uses ==
{{Cookbook|Corn Syrup}}
Major uses of corn syrup in commercially prepared foods are as a thickener, a sweetener, and a [[humectant]] (an ingredient that retains moisture and thus maintains a food's freshness).<ref name="FPD">{{cite web|last=Knehr|first=Elaine|title=Carbohydrate Sweeteners|url=http://www.foodproductdesign.com/articles/2005/05/carbohydrate-sweeteners.aspx|url-status=dead|archive-url=https://archive.today/20130102193227/http://www.foodproductdesign.com/articles/2005/05/carbohydrate-sweeteners.aspx|archive-date=2 January 2013|access-date=17 October 2008|website=Food Product Design|publisher=Virgo Publishing}}</ref> The primary ingredient in most brands of commercial "[[table syrup]]" is either regular corn syrup or high-fructose corn syrup, both of which are less expensive than [[maple syrup]].<ref>{{Cite web|url=http://www.consumerreports.org/maple-syrup/5-things-you-need-to-know-about-maple-syrup|title=5 Things You Need to Know About Maple Syrup|language=en-US|access-date=29 September 2016}}</ref>

In the United States, [[tariff-rate quota]]s for [[cane sugar]] imports raise sugar prices;<ref name="SugarImport">{{cite web|title=U.S. Sugar Import Program |url=http://www.fas.usda.gov/itp/imports/ussugar.asp |access-date=21 March 2009 |publisher=USDA |url-status=dead |archive-url=https://web.archive.org/web/20090322125930/http://www.fas.usda.gov/itp/imports/ussugar.asp |archive-date=22 March 2009 }}</ref> hence, domestically produced corn syrup and high-fructose corn syrup are less costly alternatives that are often used in American-made processed and mass-produced foods, candies, soft drinks, and fruit drinks.<ref name="FPD" />

[[Glucose syrup]] was the primary corn sweetener in the United States prior to the expanded use of [[high fructose corn syrup]] production in 1964.<ref>{{Cite book |url=https://www.worldcat.org/oclc/876051670 |title=Fructose, high fructose corn syrup, sucrose and health |date=2014 |others=James M. Rippe |isbn=978-1-4899-8077-9 |location=New York |oclc=876051670}}</ref> HFCS is a variant in which other enzymes are used to convert some of the glucose into fructose.<ref>{{cite book |last1=Hobbs |first1=Larry |editor1-last=BeMiller |editor1-first=James |editor2-last=Whistler |editor2-first=Roy |title=Sweeteners from Starch: Production, Properties and Uses |date=2009 |publisher=Elsevier Inc. |isbn=978-0-12-746275-2 |pages=808–813 |edition=3rd |url=https://talcottlab.tamu.edu//wp-content/uploads/sites/108/2019/01/Sweetners-from-starch.pdf |access-date=5 December 2019 |chapter=Starch: Chemistry and Technology}}</ref> The resulting syrup is sweeter and more soluble.{{Cn|date=January 2021}}

If mixed with [[sugar]], [[water]], and [[cream of tartar]], corn syrup can be used to make [[sugar glass]].<ref>{{Cite book|url=https://books.google.com/books?id=F-AeAQAAMAAJ&q=f+mixed+with+sugar,+water+and+cream+of+tartar,+corn+syrup+can+be+used+to+make+sugar+glass.|title=Annual Report - National Confectioners' Association of the United States|last=States|first=National Confectioners' Association of the United|date=1956|language=en}}</ref>

== History ==
[[File:Karoadvert-1917.jpg|thumb|1917 Karo advertisement encouraging corn syrup as a wartime [[sugar substitute]]]]

Corn syrup was available at [[grocery stores]] in the 19th century, as a [[generic product]] sold from a barrel.<ref name="Karo Syrup">{{Cite encyclopedia |year=2007 |title=Karo Syrup |encyclopedia=The Oxford Companion to American Food and Drink |publisher=Oxford University Press |url=https://books.google.com/books?id=AoWlCmNDA3QC&pg=PT365 |location=Oxford |last=Weinstein |first=Jay |editor-last=Smith |editor-first=Andrew F. |pages=339 |isbn=978-0-19-530796-2 |oclc=71833329}}</ref>  In 1902, the [[Corn Products Refining Company]] introduced clear, [[Bottle|bottled]] corn syrup under the brand name of '''Karo Syrup'''.<ref name="Karo Syrup" />  In 1910, the company launched one of the largest [[Advertising campaign|advertising campaigns]] ever seen.  This included full-page [[advertisements]] in [[women's magazines]] and free [[cookbooks]] full of [[recipes]] that called for Karo brand corn syrup.<ref name="Karo Syrup" />  In the 1930s, they promoted a new [[pecan pie]] recipe that featured corn syrup, followed by a similar, nut-free [[chess pie]] recipe, in a bid to drive sales.<ref name="Karo Syrup" />  Later, they promoted it as an alternative to [[maple syrup]] for [[waffles]].<ref name="Karo Syrup" /> As cooking in the home declined in the 21st century, so that fewer people made [[Sugar candy|candies]] or [[Pie in American cuisine|pies]] at home, commercial sales of Karo tended to dominate over the retail sales.<ref name="Karo Syrup" />

==See also==

* [[Candy corn]]
* [[High-fructose corn syrup]]
* [[High-maltose corn syrup]]
* [[List of syrups]]
* [[Maple syrup]]
* [[Mizuame]]
* [[Molasses]]

==References==
{{Reflist|30em}}

==External links==
*{{Commonscatinline}}

{{corn}}
{{Sugar}}

[[Category:Maize products]]
[[Category:Syrup]]
[[Category:Starch]]
[[Category:Corn-based sweeteners|*]]