High fructose corn syrup
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High fructose corn syrup (HFCS) is a newer and sweeter form of corn syrup. Like ordinary corn syrup, the high fructose variety is made from corn starch using enzymes. The production process of HFCS was developed by Japanese researchers in the 1970s. HFCS was rapidly introduced in many processed foods and soda drinks in the US over the period of about 1975–1985, and usage continues to increase as sugar use decreases at a nearly one to one level (Bray, 2004 & U.S. Department of Agriculture, Economic Research Service, Sugar and Sweetener Yearbook series, Tables 50–52.). There are three main reasons for this switch; first is cost, as HFCS is a bit cheaper due to corn subsidies and import sugar tariffs. The second reason is that it is a liquid which is easier to blend and transport. The third is that a product made with HFCS has a much longer shelf life. (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)
By increasing the fructose content of corn syrup (primarily glucose) through enzymatic processing, the syrup is more comparable to table sugar (sucrose) in sweetness. This makes it useful to manufacturers as a possible substitute for sugar in soft drinks and other processed foods. Common commercial grades of high fructose corn syrup include fructose contents of 42%, 55%, or 90%. The 55% grade is most commonly used in soft drinks.
Unlike sucrose, HFCS consists of a mixture of glucose and fructose, which doesn't require an enzymatic step to break it down before absorption in the intestine.
Some people suspect that over-consumption of HFCS may be a main contributor to the epidemic of diabetes in the US. [1] Fructose is probably less cariogenic (cavity-causing) than sucrose.
Contents
[hide]Comparison to other sugars
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. 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 (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 "50% glucose and 50% fructose." This may easily be misunderstood. Pure sucrose contains only sucrose molecules. It contains no free fructose molecules and no free glucose molecules. It contains fructose moieties and sucrose moieties, but these moieties are bound together into sucrose molecules and thus are not free. When talking about chemistry, a "mixture" is defined as a blend of two or more different molecules. Thus, strictly speaking, it would be incorrect to say that sucrose is a mixture of 50% fructose and 50% glucose. On the other hand, because sucrose is broken down in the small intestine to fructose and glucose, one could argue that after ingested sucrose enters the small intestine and is broken down, it is metabolized by the body like a mixture of 50% glucose and 50% fructose.
HFCS can have a high or low fructose content, with a corresponding difference in sweetness. 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, as well as containing some sucrose and other sugars.
Production
High-fructose corn syrup (HFCS) is produced by processing corn starch to yield glucose, and then processing the glucose to produce a syrup that contains fructose. First, cornstarch is treated with alpha-amylase to produce shorter chains of sugars called oligosaccharides. Then, an enzyme called glucoamylase breaks the sugar chains down even further to yield the simple sugar glucose. The third enzyme, glucose isomerase, converts glucose to a mixture of about 42% fructose and 50–52% glucose with some other sugars mixed in. While alpha-amylase and glucoamylase are added directly to the slurry, glucose-isomerase is packed into columns and the sugar mixture is then passed over it. 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. Numerous ion-exchange and evaporation steps are also part of the overall process.
Sweetener consumption patterns
In the United States
The accompanying graph shows the consumption of sweeteners per capita in the United States since 1966. Since HFCS and sucrose (cane and beet sugars) provide almost identical proportions of fructose and glucose, no metabolic changes would be expected from substituting one for the other. However, 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. This would be true whether the added sweetener was HFCS, table sugar, or any other glucose-fructose mixture.
International markets
HFCS is produced in the industrialized countries.The production of HFCS is dependent on the agricultural, especially sugar, policy.
In Europe, due to the fact that HFCS (isoglucose) is under the adjustment of production, the greater availability of cane sugar over maize would make its production there uneconomical. Also Europe does not allow genetically modifed foods (GMOs) and therefore does not allow HFCS.
In Japan, HFCS consumption accounts for one quarter of total sweetener consumption.
Health effect controversy
Overview
The average American consumed approximately 19.2 kg of HFCS versus 20 kg of sugar in 2004.[citation needed] Where HFCS is not used or rarely used, the sugar consumption per person can be higher than the USA; for example, the 2002 figures for some countries are: USA 32.4 kg, EU 40.1 kg, Brazil 59.7 kg, and Australia 56.2 kg.[2]
One study concluded that fructose "produced significantly higher fasting plasma triacylglycerol values than did the glucose diet in men" and "if plasma triacylglycerols are a risk factor for cardiovascular disease, then diets high in fructose may be undesirable"[3]. A study in mice suggests that fructose increases adiposity.[4] However, these studies looked at the effects of fructose alone. As noted by the U.S. Food and Drug Administration in 1996, the saccharide composition (glucose to fructose ratio) of HFCS is approximately the same as that of honey, invert sugar and the disaccharide sucrose (or table sugar).
A more recent study found a link exists between obesity and high HFCS consumption, especially from soft drinks.[5]
However, the obesity epidemic has many contributing factors. University of California, Davis nutrition researcher Peter Havel has pointed out that while there are likely differences between sweeteners, "the increased consumption of fat, the increased consumption of all sugars, and inactivity are all to blame for the obesity epidemic."[6]
Labeling restrictions
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" despite containing high fructose corn syrup. While the 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 modifed (GMO) enzyme required to produce it.[7]
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