Corn syrup

Corn syrup is any of variety of forms syrup (thick, viscous liquid, containing a large amount of dissolved sugars, with little tendency to deposit crystals) made using corn starch as a feedstock, and composed mainly of glucose. Corn syrup is a natural sweetener used in a variety of products, which may be labelled "all natural" in the United States. It is often used to soften texture, add volume, inhibit crystallization, and enhance flavor (Knehr 2005).

The varieties of sweeteners listed as corn syrup differ in the amount of glucose present, among other factors (clor, flavor additives, cloudiness, etc.). A commercial “corn syrup” may contain between 20% and 98% dextrose (glucose) (SA 2007). The more general term glucose syrup is often used synonymously with corn syrup, since glucose syrup is most commonly made from corn starch (SA 2007). Technically though, glucose syrup is any liquid starch hydrolysate of mono, di, and higher saccharides (ISI 2006) and can be made from starch from any source, of which wheat, rice and potatoes are the most common sources.

High fructose corn syrup (HFCS) is a variant of corn syrup in which other enzymes are used to convert some of the glucose into fructose. The resulting syrup is sweeter and more soluble.

Corn syrup production and use

Starch is a complex carbohydrate, specifically a polysaccharide, that is used by plants as a way to store glucose. After cellulose, starch is the most abundant polysaccharide in plant cells. In pure form, starch is insoluble in cold water. Animals and plants digest starch, converting it to glucose to serve as a source of energy. Starch is a major source of carbohydrates in human diets,

Hydrolysis is the term used to describe the process where starch is converted into various sweeteners. Commercially, in the case of corn starch, this involves a series of two enzymatic reactions to convert the corn starch to corn syrup (Ophardt 2003). Prior to this, the corn is processed and refined in order to separate the starch from protein and other materials, which are used for animal feed.

The starch is hydrolyzed using acid, acid-enzyme, or enzyme-enzyme catalyzed processes, with the first enzyme typically alpha amylase, which produces about 10-20 % glucose, and further treatment with the enzyme glucoamylase, which yields 93-96% glucose. Acid hydrolysis may involve using a weak solution of hydrochlorica acid and heat to help break down the molecules of starch. The varying sweetness of the corn syrup is done according to how long the hydrolysis is allowed to proceed; the longer the hydrolysis, the sweeter the syrup.

In reality, the term corn syrup refers to a group of sweeteners that differ in the amount of dextrose (glucose) present (20 to 98%), and that may also have caramel flavor and coloring added (dark corn syrup) or color and cloudiness removed (light corn syrup), and so froth. When corn syrup is concentrated to the point that it has less than 10% water, it can be listed as “corn syrup solids” (or dried glucose syrup, or glucose syrup solids, in an ingredient statement, as long as the glucose content is at least 88% of the weight of the concentrated syrup (SA 2007).

Because of its mild sweetness, corn syrup may be used in conjunction with high intensity sweeteners. Corn syrups major use is in commercially prepared foods as a thickener and for its moisture-retaining (humectant) properties, which keep foods moist and helps to maintain freshness.

Some foods that commonly contain corn syrup are: baking and cooking ingredients, beverages, soft drinks, breads, breakfast cereals, breakfast pastries, candy bars, condiments, cookies and cakes, cough syrups, crackers, dairy, drink mixers, frozen foods, ice creams, infant formula, jams and jellies, syrups, meats, pastries, salad dressings, sauces, snacks, soda, and microwavable soup.

High fructose corn syrup

High fructose corn syrup (HFCS) refers to a group of corn syrups that have undergone enzymatic processing in order to increase the fructose content. This processing converts the dextrose (glucose) sugars into fructose sugars, which are sweeter.

Typically types of HFCS include HFCS 90 (most commonly used in baked goods), which is approximately 90% fructose and 10% glucose; HFCS 55 (most commonly used in soft drinks), which is approximately 55% fructose and 45% glucose; and HFCS 42 (most commonly used in sports drinks), which is approximately 42% fructose and 58% glucose.

There is some controversy over the use of HFCS as a food additive. Increasingly, manufacturers are utilizing HFCS in a variety of foods such as breads, cereals, soft drinks, condiments, and so forth.

The process by which HFCS is produced was first developed by Richard O. Marshall and Earl R. Kooi in 1957 (Marshall et al. 1957) and refined by Japanese researchers in the 1970s. HFCS was rapidly introduced in many processed foods and soft drinks in the United States over the period of about 1975–1985.

In terms of sweetness, HFCS 55 is comparable to table sugar (sucrose) (CRA 2007). This makes it useful to manufacturers as a possible substitute for sugar in soft drinks and other processed foods. HFCS 90 is sweeter than table sugar, while HFCS 42 is not as sweet as table sugar.

Since its introduction, HFCS has begun to replace sugar in various processed foods in the USA. The main reasons for this switch are (White 1992):

• HFCS is somewhat cheaper due to the relative abundance of corn, farm subsidies and sugar import tariffs in the United States (Pollan 2003).
• HFCS is easier to blend and transport because it is a liquid (Hanover and White 1993).
• HFCS usage leads to products with much longer shelf life.

Comparison of HFCS to other sugars

Cane sugar

Cane sugar is relatively pure sucrose. Sucrose is a disaccharide, as opposed to glucose and fructose, which are monosaccharides. Each molecule of sucrose is composed of one unit each of fructose and glucose linked together with a relatively weak glycosidic bond. A molecule of sucrose (with a chemical formula of C₁₂H₂₂O₁₁) can be broken down into a molecule of glucose (C₆H₁₂O₆) plus a molecule of fructose (also C₆H₁₂O₆. Sucrose is broken down during digestion into fructose and glucose through hydrolysis by the enzyme sucrase.

Because sucrose can be broken down into fructose and glucose, some people say that sucrose is composed "50% glucose and 50% fructose." This, strictly speaking, is incorrect, because the fructose and glucose in sucrose are linked together and thus it is a different molecule. On the other hand, because sucrose is broken down in weakly acidic environments into its constituent monosaccharides, namely fructose and glucose, it is not incorrect to describe its constituents as 50% glucose and 50% fructose. This same process occurs in the stomach and in the small intestine during the digestion of sucrose into fructose and glucose. According to two published reports, sucrose is metabolized by the body like a mixture of 50% glucose and 50% fructose and no differently from HFCS (Melanson et al. 2007; FPD 2006).

HFCS 50 is chemically quite similar to cane sugar as cane sugar sucrose is made of 50% fructose and 50% glucose while HFCS 55 is made of 55% fructose and 45% glucose. Both HFCS and sucrose have approximately 4 kcal per gram of solid.

Honey

Honey is a mixture of different types of sugars, water, and small amounts of other compounds. Honey typically has a fructose/glucose ratio similar to HFCS 55, as well as containing some sucrose and other sugars. Honey, HFCS, and sucrose have the same number of calories, having approximately 4 kcal per gram of solid.

Production

High-fructose corn syrup is produced by milling corn to produce corn starch, then processing that corn starch to yield corn syrup that is almost entirely glucose, and then adding enzymes that change the glucose into fructose. The resulting syrup (after enzyme conversion) contains approximately 90% fructose and is HFCS 90. To make the other common forms of HFCS (HFCS 55 and HFCS 42). the HFCS 90 is mixed with 100% glucose corn syrup in the appropriate ratios to form the desired HFCS syrup. The enzyme process that changes the 100% glucose corn syrup into HFCS 90 is as follows:

1. Cornstarch is treated with alpha-amylase to produce shorter chains of sugars called oligosaccharides.
2. Glucoamylase breaks the sugar chains down even further to yield the simple sugar glucose.
3. Glucose isomerase converts glucose to a mixture of about 42% fructose and 50–52% glucose with some other sugars mixed in.

While inexpensive alpha-amylase and glucoamylase are added directly to the slurry and used only once, the more costly glucose-isomerase is packed into columns and the sugar mixture is then passed over it, allowing it to be used repeatedly until it loses its activity. This 42–43% fructose glucose mixture is then subjected to a liquid chromatography step where the fructose is enriched to approximately 90%. The 90% fructose is then back-blended with 42% fructose to achieve a 55% fructose final product. Most manufacturers use carbon absorption for impurity removal. Numerous filtration, ion-exchange, and evaporation steps are also part of the overall process.

Controversy

The dominance of HFCS in some markets, particularly in the United States, has generated some controversies in terms of market forces and health.

File:Usda sweeteners.jpg

US sweetener consumption, 1966-2004. It is apparent from this graph that overall sweetener consumption, and in particular glucose-fructose mixtures, has increased since the introduction of HFCS. Thus, the proportion of fructose as a component of overall sweetener intake in the United States has increased since the early 1980s.

In the United States, there are various price supports and sugar quotes, imposed since May 1982, that make importing of sugar expensive, and make HFCS, derived from corn, more economical. Additional support for corn (maize) growers also contributes. In the European Union, the sugar price is close to the market price, and the greater availability of cane sugar over maize would make HFCS production there uneconomical. In Japan, HFCS consumption accounts for one quarter of total sweetener consumption [[1]].

There also are well-publicized concerns that HFCS may not be as healthy as sucrose or glucose, based on various research done on fructose, showing higher fasting plasma triacylglycerol values in men (Raatz 2000), increase of obesity in mice (Jurgens et al. 2005), and reports that large quantities of fructose stimulates the liver to produce triglycerides, promotes glycation of proteins, and induces insulin resistance (Faeh et al. 2005). Nielsen and Popkin (2004) fouond an association between obesity and high HFCS consumption.

On the other hand, others note that such studies were on the effects of pure fructose intakes in various solutions not of HFCS and that consumption of high sugar in general would correlate with obesity and health concerns. According to research provided by Melanson et al. (2007) effects of HFCS to date mimic those of sucrose and not of pure fructose in certain individuals. High fructose corn syrup comes in different ratios of fructose and glucose, which are considered to be roughly the same products produced by the breakdown of sucrose (cane/table sugar) in the body. Melanson et al. (2006) studied the effects of HFCS and sucrose sweetened drinks on blood glucose, insulin, leptin, and ghrelin levels, and found no significant differences in any of these parameters.

Of course, another issue is concern from high fructose consumption in itself, whether from HFCS or other commercially produced sources, as high fructose consumption has been linked to heart disease, raising blood levels of cholesterol and triglyceride, make blood cells more prone to clotting, and possibly acceleration of the aging process (Challem 1995).

Some beverage manufacturers have returned to cane sugar as a sweetener, maintaining that there is a noticeable difference in taste.

References

ISBN links support NWE through referral fees

Corn Refiners Association (CRA). 2007.

By Elaine Knehr

International Starch Institute (ISI). 2006. Starch & Sweetener Dictionary Contributing Editor 2005

.

).

Ophardt, C. E. 2003. Virtual Chembook. .

Sugar Association (SA 2007)

ref>(White JS. 1992. Fructose syrup: production, properties and applications, in FW Schenck & RE Hebeda, eds, Starch Hydrolysis Products – Worldwide Technology, Production, and Applications. VCH Publishers, Inc. 177-200)</ref>

{Cite journal|last=Jurgens|first=Hella|coauthors=et al.|url=http://www.obesityresearch.org/cgi/content/abstract/13/7/1146%7Ctitle=Consuming Fructose-sweetened Beverages Increases Body Adiposity in Mice|journal=Obesity Res|volume=13|pages=1146-1156|year=2005}}</ref>

[2]

Nutrition. 2007 Feb;23(2):103-12. Links

Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women.Melanson KJ, Zukley L, Lowndes J, Nguyen V, Angelopoulos TJ, Rippe JM. Department of Nutrition and Food Sciences, University of Rhode Island, Kingston, Rhode Island, USA.

FPD. 2006. [3].Similarities Between HFCS and Sucrose Revealed

Posted on: 04/14/2006

Bantle, John P. and Susan K. Raatz, William Thomas and Angeliki Georgopoulos (November 2000). Effects of dietary fructose on plasma lipids in healthy subjects. American Journal of Clinical Nutrition 72 (5): 1128-1134.</ref>

Melanson K et al. Eating Rate and Satiation. Obesity Society (NAASO) 2006 Annual Meeting. October 20-24, 2006, Hynes Convention Center, Boston, Massachusett </ref>

• The Nutrition Reporter "Fructose: Maybe Not So Natural...and Not So Safe" Fructose

Maybe Not So Natural...and Not So Safe Copyright © 1995 by Jack Challem, The Nutrition Reporter™ All rights reserved.

External links

• How corn is turned into corn syrup.
• Oregon State University Food Resource: Corn Syrup
• "Is high-fructose corn syrup making us fat? It's a sticky subject" (Article by Karen Gaudette, Seattle Times)
• "Does This Goo Make You Groan?" or "A Sweetener With a Bad Rap" (Article by Melanie Warner, New York Times) complete text available
• HFCS Facts (Industry site)
• "Scientists Stonewall on Spurious Soda Scare"
• Foods containing High Fructose Corn Syrup
• Cargill Foods (Largest provider of HFCS to the food & beverage industry)
• "Audio broadcast linking HFCS Industry to Diabetes/Obesity Epidemic"
• "The Double Danger of High Fructose Corn Syrup"
• "Consumption of soft drinks and high-fructose corn syrup linked to obesity and diabetes"
• "The Murky World of High-Fructose Corn Syrup"
• "We're drowning in high fructose corn syrup. Do the risks go beyond our waistline?" (San Francisco Chronicle)

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