High-fructose corn syrup

High-fructose corn syrup (HFCS) is any of a group of corn syrups that has undergone enzymatic processing to increase its fructose content, and is then mixed with pure corn syrup (100% glucose), becoming a high-fructose corn syrup; the types are: HFCS 90 (mostly for making HFCS 55), approximately 90% fructose and 10% glucose; HFCS 55 (mostly used in soft drinks), approximately 55% fructose and 45% glucose; and HFCS 42 (used in most foods and baked goods), approximately 42% fructose and 58% glucose.

The process by which HFCS is produced was first developed by Richard Off. Marshalle and Earl P. Kooi in 1927. The industrial production process was refined by Dr. Y. Takasaki at Agency of Industrial Science and Technology of Ministry of International Trade and Industry of Japan in 1965-1970. HFCS was rapidly introduced to many processed foods and soft drinks in the U.S. from about 1975 to1985.

Per relative sweetness, HFCS 55 is comparable to table sugar (sucrose), a disaccharide of fructose and glucose. That makes it useful to food manufacturers as a substitute for sucrose in soft drinks and processed foods. HFCS 90 is sweeter than sucrose, HFCS 42 is less sweet than sucrose.

Use as a replacement for sugar
Since its introduction, HFCS has begun to replace sugar in various processed foods in the USA. The main reasons for this switch are:
 * HFCS is somewhat cheaper in the United States due to a combination of corn subsidies and sugar tariffs.
 * HFCS is easier to blend and transport because it is a liquid.

Cane and beet sugar
Cane sugar and Beet sugar are both relatively pure sucrose. While the glucose and fructose which are the two components of HFCS are monosaccharides, sucrose is a disaccharide composed of glucose and fructose 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 — an isomer of glucose) in a weakly acidic environment. Sucrose is broken down during digestion into fructose and glucose through hydrolysis by the enzyme sucrase, by which the body regulates the rate of sucrose breakdown. Without this regulation mechanism, the body has less control over the rate of sugar absorption into the bloodstream.

The fact that sucrose is composed of glucose and fructose units chemically bonded complicates the comparison between cane sugar and HFCS. Sucrose, glucose and fructose are unique, distinct molecules. Sucrose is broken down into its constituent monosaccharides—namely, fructose and glucose—in weakly acidic environments by a process called inversion. This same process occurs in the stomach and in the small intestine during the digestion of sucrose into fructose and glucose. People with sucrase deficiency cannot digest (break down) sucrose and thus exhibit sucrose intolerance.

Both HFCS and sucrose have approximately 4 kcal per gram of solid if the HFCS is dried; HFCS has approximately 3 kcal per gram in its liquid form.

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; honey and HFCS both have about 3 kcal per gram in liquid form.

Production
High-fructose corn syrup is produced by milling corn to produce corn starch, then processing that corn starch to yield corn syrup which is almost entirely glucose, and then adding enzymes which 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. The enzyme process which 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) Xylose isomerase (aka 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.

Measuring concentration of HFCS
The units of measurement for sugars including HFCS are degrees Brix (symbol °Bx). Brix is a measurement of the mass ratio of dissolved sugars to water in a liquid. A 25 °Bx solution has 25 grams of sugar per 100 grams of liquid (25% w/w). Or, to put it another way, there are 25 grams of sugar and 75 grams of water in the 100 grams of solution. The Brix measurement was introduced by Antoine Brix.

When an infrared Brix sensor is used, it measures the vibrational frequency of the high-fructose corn syrup molecules, giving a Brix degrees measurement. This will not be the same measurement as Brix degrees using a density or refractive index measurement because it will specifically measure dissolved sugar concentration instead of all dissolved solids. When a refractometer is used, it is correct to report the result as "refractometric dried substance" (RDS). One might speak of a liquid as being 20 °Bx RDS. This is a measure of percent by weight of total dried solids and, although not technically the same as Brix degrees determined through an infrared method, renders an accurate measurement of sucrose content since the majority of dried solids are in fact sucrose. The advent of in-line infrared Brix measurement sensors have made measuring the amount of dissolved HFCS in products economical using a direct measurement. It also gives the possibility of a direct volume/volume measurement.

Recently an isotopic method for quantifying sweeteners derived from corn and sugar cane was developed by Jahren et al. which permits measurement of corn syrup and cane sugar derived sweeteners in humans thus allowing dietary assessment of the intake of these substances relative to total intake.

In the United States


Because of a system of price supports and sugar quotas imposed since May 1982, importing sugar into the United States is prohibitively expensive. High-fructose corn syrup, derived from corn, is more economical since the American and Canadian prices of sugar are artificially far higher than the global price of sugar and the price of #2 corn is artificially low due to both government subsidies and dumping on the market as farmers produce more corn annually. The food industry turned to HFCS as a substitute, with both Coca-Cola and Pepsi switching to HFCS in 1984.

The preference for high-fructose corn syrup over cane sugar among the vast majority of American food and beverage manufacturers is largely due to U.S. import quotas and tariffs on sugar. These tariffs significantly increase the domestic U.S. price for sugar, forcing Americans to pay more than twice the world price for sugar, thus making high-fructose corn syrup an attractive substitute in U.S. markets. For instance, soft drink makers like Coca-Cola use sugar in other nations, but use high-fructose corn syrup in their U.S. products. Large corporations, such as Archer Daniels Midland, lobby for the continuation of these subsidies.

Other countries, including Mexico, typically use sugar in soft drinks. Some Americans seek out Mexican Coke in ethnic groceries, because they feel it tastes better or is healthier than Coke made with HFCS, and because they believe it will have less effect on obesity. 

The average American consumed approximately 28.4 kg of HFCS in 2005, versus 26.7 kg of sucrose sugar. In countries where HFCS is not used or rarely used, sucrose consumption per person may be higher than in the USA; Sucrose consumption per person from various locations is show below (2002): Of course, in terms of total sugars consumed, the figures from countries where HFCS is not used should be compared to the sum of the sucrose and HFCS figures from countries where HFCS consumption is significant.
 * USA: 32.4 kg
 * EU: 40.1 kg
 * Brazil: 59.7 kg
 * Australia: 56.2 kg

International markets
In the European Union (EU), HFCS, known as isoglucose, has been subject to production quotas since 1977. Production of isoglucose in the EU has been limited to 507,000 metric tons, equivalent to about 2%-3% of sugar production. Therefore, wide scale replacement of sugar has not occurred in the EU. In Japan, HFCS consumption accounts for one quarter of total sweetener consumption.

Health effects
There are indications that soda and sweet drinks provide a greater proportion of daily calories than any other food in the American diet. Overconsumption of sugars has been linked to adverse health effects, such as obesity, and most of these effects are similar for HFCS and sucrose. There is a correlation between the rise of obesity in the U.S. and the use of HFCS for sweetening beverages and foods. The controversy largely comes down to whether this is coincidence or a causal relationship. Some critics of HFCS do not claim that it is any worse than similar quantities of sucrose would be, but rather focus on its prominent role in the overconsumption of sugar; for example, encouraging overconsumption through its low cost.

The possible difference in health effects between sucrose and HFCS could come from the difference in chemical make up between them. HFCS 55 (the type most commonly used in soft drinks) is made up of 55% fructose and 45% glucose. By contrast, sucrose is made up of 50% fructose and 50% glucose. Furthermore, the fructose and glucose in HFCS 55 are in the form of separate molecules; by contrast, the fructose and glucose that are contained in sucrose are joined together to form a single molecule (called a disaccharide). This chemical difference may be less significant in many beverages that are sweetened with sucrose. This is because many beverages are strongly acidic, and the acid in the beverage will cause the sucrose to separate into its component parts of glucose and fructose. The amount of sucrose converted will depend on the temperature the beverage is kept at and the amount of time it is kept at this temperature.

There are a number of relevant studies published in peer reviewed journals suggesting a link between high fructose diets and adverse health effects. Studies on the effect of fructose, as reviewed by Elliot et al., implicate increased consumption of fructose (due primarily to the increased consumption of sugars but also partly due to the slightly higher fructose content of HFCS as compared to sucrose) in obesity and insulin resistance. Chi-Tang Ho et al. found that soft drinks sweetened with HFCS are up to 10 times richer in harmful carbonyl compounds, such as methylglyoxal, than a diet soft drink control. Carbonyl compounds are elevated in people with diabetes and are blamed for causing diabetic complications such as foot ulcers and eye and nerve damage; Furthermore, a study in mice suggests that fructose increases obesity. Large quantities of fructose stimulate the liver to produce triglycerides, promotes glycation of proteins and induces insulin resistance. According to one study, the average American consumes nearly 70 pounds of HFCS per annum, marking HFCS as a major contributor to the rising rates of obesity in the last generation.

A 2007 study also raised concerns of possible liver damage as a result of HFCS in combination with a high fat diet and a sedentary lifestyle.

In contrast to the above studies other papers (often funded by corn refiners and/or the American Beverage Institute) suggest HFCS has no ill health affects. A review supported by Tate & Lyle, a large corn refiner which makes a significant profit from the sale of corn-based products, concluded "that HFCS does not appear to contribute to overweight and obesity any differently than do other energy sources."

In addition, some of the above-referenced studies have addressed fructose specifically, not sweeteners such as HFCS or sucrose which contain fructose in combination with other sugars. Thus, although they indicate that high fructose intake should be avoided, they don't necessarily indicate that HFCS is worse than sucrose intake, except insofar as HFCS contains 10% more fructose. Studies which have compared HFCS to sucrose (as opposed to pure fructose) find that they have essentially identical physiological effects. For instance, Melanson et al. (2006), studied the effects of HFCS and sucrose sweetened drinks on blood glucose, insulin, leptin, and ghrelin levels. They found no significant differences in any of these parameters.

Perrigue et al. (2006) compared the effects of isocaloric servings of colas sweetened with HFCS 45, HFCS 55, sucrose, and aspartame on satiety and subsequent energy intake. They found that all of the drinks with caloric sweeteners produced similar satiety responses, and had the same effects on subsequent energy intake. Taken together with Melanson et al. (2006), this study suggests that there is little or no evidence for the hypothesis that HFCS is different from sucrose in its effects on appetite or on metabolic processes involved in fat storage.

It should be noted that both the Perrigue et al. study and the Melanson et al. study were funded by "the American Beverage Institute and the Corn Refiners Association." suggesting a possible conflict of interest in regards to the study of HFCS.

One much-publicized 2004 study found an association between obesity and high HFCS consumption, especially from soft drinks. However, this study provided only correlative data. One of the study coauthors, Dr. Barry M. Popkin, is quoted in the New York Times as saying, "I don't think there should be a perception that high-fructose corn syrup has caused obesity until we know more." In the same article, Walter Willett, chair of the nutrition department of the Harvard School of Public Health, is quoted as saying, "There's no substantial evidence to support the idea that high-fructose corn syrup is somehow responsible for obesity .... If there was no high-fructose corn syrup, I don't think we would see a change in anything important." Willett also recommends drinking water over soft drinks containing sugars or high-fructose corn syrup.

Labeling as "natural"
In May 2006, the Center for Science in the Public Interest (CSPI) threatened to file a lawsuit against Cadbury Schweppes for labeling 7 Up as "All Natural" or "100% Natural", despite containing high-fructose corn syrup. While the U.S. FDA has no definition of "natural", CSPI claims that HFCS is not a “natural” ingredient due to the high level of processing and the use of at least one genetically modified (GMO) enzyme required to produce it. On January 12, 2007, Cadbury Schweppes agreed to stop calling 7 Up "All Natural". They now label it "100% Natural Flavors".

Snapple (another Cadbury-Schweppes brand) is well-known for being labeled "all-natural", but most varieties contain HFCS. Newman's Own Lemonade and Limeade are labeled as "all-natural" but also contain HFCS. Bread produced by Nature's Own Bread is labeled as having "no artificial preservatives, colors, or flavors", though some varieties contain HFCS. Still, as the U.S. FDA has no general definition of "natural", a company may refer to its product as "all natural", regardless of the ingredients, in most cases. However, FDA does prohibit beverages that contain less than 100% juice from using phrases like 100% natural and 100% pure. 21 CFR 101.35(l) This might apply to 7UP based on vignettes of lemon, lime, or other fruit which could be construed as purporting to contain juice.

Television ads
In September 2008, the Corn Refiners Association launched a series of United States television advertisements that claim that HFCS "is made from corn", "doesn't have artificial ingredients", "has the same calories as sugar or honey", "is nutritionally the same as sugar", and "is fine in moderation". The ads feature actors portraying roles in upbeat domestic situations with sugary foods, with one actor disparaging a food's HFCS content but being unable to explain why, and another actor rebuking the comments with these claims. Finally, the ads each advertise the URL http://www.sweetsurprise.com/ with more information provided by the Corn Refiners Association. As HFCS is a controversial topic, parodies and criticisms of the ads have appeared on YouTube.

Taste
Some beverage manufacturers, such as Jones Soda, Goose Island Brewery, and Steaz, use sugar rather than high fructose corn syrup in their products. These companies maintain in their advertising that there is a noticeable difference in taste between the two sweeteners.