By John S. White, Ph.D.
Contributing Editor
Corn syrups likely date to the 1811 discovery by G.S.C. Kirchoff that starch—a non-sweet polymer found largely in cereal grains where glucose monomers are bonded together—when boiled with diluted acid, produces sweet-tasting syrup. The initial syrups made in Europe from wheat starch used poorly controlled processes to hydrolyze the starch mostly to glucose, and served initially as a substitute for scarce sugar resulting from the British blockade of Europe against Napoleon.
In the latter half of the 19th century, the bountiful U.S. corn crop, with its high starch content, was recognized as an excellent starting material for a whole host of starch-based products. This evolved into the present day corn wet milling industry.
Engineering innovations providing greater control of starch hydrolysis and better removal of highly flavored and/or colored byproducts in the early 20th century allowed the development of new product families like corn syrups, intermediate in length between large starch polymers and small monomeric glucose. High-fructose corn syrup (HFCS) development awaited the perfection of enzyme-catalyzed isomerization and chromatographic separation processes in the 1960s that permitted efficient conversion of glucose to fructose. With HFCS, the corn wet milling industry now had a liquid product of comparable sweetness to sucrose that could successfully compete in the liquid sweetener market.
Quelling nutritional controversy
Regular and dried corn syrups are codified by the international Codex Alimentarius Commission and by FDA’s Code of Federal Regulations, Title 21, Section 168. Corn syrups and HFCS are GRAS, and their specifications are listed in the Food Chemicals Codex and the U.S. Pharmacopeia/National Formulary.
HFCS has been blamed for being uniquely responsible among caloric sweeteners for the obesity epidemic. Although this was initially proposed by several scientists as a hypothesis in 2004, it has unfortunately been embraced by some as a truism despite a lack of substantive evidence—even in the wake of the later acknowledgment by the original proponents that their hypothesis was in error.
The practice of simplifying experimental designs when studying complex nutitional systems has been taken to such an extreme with HFCS that contemporary experimental designs do not remotely resemble the human diet. The effects of pure fructose vs. pure glucose are compared in the lab, although each is rarely eaten alone in the normal human diet, and testing is done at levels far higher than typically consumed. This is inappropriate for several reasons:
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Fructose and glucose are typically consumed together, whether from natural sources like fruits, vegetables and nuts, or from added sugars like sucrose, HFCS, fruit-juice concentrates and honey—the fructose-glucose ratio in all these sources is roughly 50:50;
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There is generally more glucose in the human diet than fructose due to the prevalence of all-glucose starches, maltodextrins, regular corn syrups and glucose (dextrose);
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Fructose-containing foods are consumed throughout the day, rather than in the single slug-dose frequently employed in experimental systems;
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The extreme fructose levels tested in humans and animals exceed human intake by 2 to 7 times;
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The fructose-glucose composition of HFCS is not unique, but rather is nearly identical to that of sucrose, fruit-juice concentrates and honey.
There is no compelling evidence that HFCS is a risk factor under typical use conditions (moderate consumption, equivalent or more glucose, multiple meals). Likewise, since there is no evidence that HFCS is metabolized differently from other caloric sweeteners, there is no nutritional justification to reformulate and replace HFCS with sucrose or fruit-juice concentrates. (Curious readers should refer to recent confirming statements by the American Medical Association along with the American Dietetic Association.)
Regular corn syrups and HFCS have a long history of usefulness in the U.S. food supply. Though sometimes confused, they are distinct products and highly valued for their unique compositions and functionality in a wide variety of applications. HFCS has been a source of controversy in recent years, yet there is no data to show it is a unique health risk, nor are there significant compositional or metabolic differences between HFCS and sucrose.
John S. White consults for a variety of food and beverage companies and trade organizations in the area of nutritive sweeteners. He has worked with nutritive sweeteners for 28 years and established his consulting firm, WHITE Technical Research, Argenta, IL, in 1994. He holds a B.A. in biology from the University of California at San Diego and a Ph.D. in biochemistry from the University of Utah and was a postdoctoral fellow and visiting assistant professor of biochemistry at the University of Illinois, Urbana-Champaign. For more information on high fructose corn syrup, visit http://www.sweetsurprise.com/.
