High Fructose Corn Syrup

November 4, 2004

Most of us (with the possible exception of some of our more junior associates) did not, as children, have high fructose corn syrup in our foods. But as frequent visitors to food production plants around the country it has been hard not to notice that high fructose corn syrup has quickly become the primary sweetener in everything from soda pop to peanut butter. Where did high fructose corn syrup suddenly come from? What happened to sugar?

Until 1957 there was no such thing as high fructose corn syrup because, until that time, people had operated with the understanding – a correct understanding, in fact – that there is no fructose in corn syrup. Corn syrup contains another sugar molecule, considerably less sweet than fructose, called glucose. In 1957, a pair of researchers named Marshall and Kooi developed in their laboratory an enzyme called glucose isomerase that remarkably – actually, astonishingly – could work on corn syrup to rearrange the molecular composition of glucose and convert it to fructose. Glucose isomerase brings about the isomerization, or rearrangement, of glucose, hence the name. The more that the natural glucose in corn syrup is converted by the enzyme to fructose, the sweeter the syrup becomes. High fructose corn syrup means that a high percentage of the glucose is converted to fructose. Corn syrup, typically a mildly sweet sweetener, suddenly had the potential to become strikingly sweet.

The significance of this simple conversion was not lost on United States corn refiners who, because of federal subsidies and other reasons, have no lack of corn to work with. Federal and industrial research was anyway fervently researching new things to do with all the corn produced here (which brings up a tangential, but important, point: the ubiquity of corn in this country plays a role on presumptions that the OU makes when evaluating certain Pesach questions: do we ask a Jewish-owned company to sell during Pesach to a non-Jew the ingredients in his warehouse like vinegar, or ethanol, or vinegar-containing ketchup, ingredients which may be derived from chametz? Since the vast majority of alcohol and vinegar is corn-based in this country, in cases where we cannot determine the specific raw material used we presume that the alcohol or vinegar is corn based. In Europe, where wheat is used for these products on a larger scale, the OU presumes that these products are chametz-based). The potential value of high fructose corn syrup, compared to standard corn syrup was easily grasped: a recipe that required a fixed amount of corn syrup to sweeten a food could afford to use less corn syrup without sacrificing any sweetness.

But by far the more profound ramification of the new existence of high fructose corn syrup was its impact on the sugar industry. A reference to what those in the sweeteners business call the sweetness scale underlines the point:

Relative Sweetness Scale – Sucrose = 100
Compound Rating
Sucrose 100
Fructose 140
High Fructose Corn Syrup 120-160
Glucose 70-80
Galactose 35
Maltose 30-50
Lactose 20

Refined, or table sugar (also called cane or beet sugar), the sugar that has probably been the biggest trade commodity in the history of the world, the sugar that we add to our tea and coffee, is sucrose. Sucrose is 100 on the sweetness scale and glucose is 70-80. Glucose corn syrup was never a serious rival to refined sugar in the sweeteners industry because it is not as sweet. But when the glucose in corn syrup is converted to fructose, corn syrup can be sweeter than sugar, depending on how much of the glucose is actually converted to fructose. The two standard high fructose corn syrups sold today are 42% high fructose corn syrup and 55% high fructose corn syrup. 42%, which refers to the percentage of glucose converted to fructose, is about as sweet as sucrose, or liquid sugar; 55% high fructose corn syrup is sweeter than liquid sugar. And in the U.S., where corn is plentiful, corn syrup is not expensive to produce. High fructose corn syrup was as sweet, if not sweeter than sugar, and cheap to make.

When, therefore, high fructose corn syrup began to be produced on an industrial scale in the 1970’s, high fructose corn syrup rapidly swallowed up much of the sweeteners market. A Time Magazine article in 1974 described the stupefaction of sugar producers when, in part due to the emergence of high fructose corn syrup, they began to notice that the annual consumption of sugar was falling. “It was like telling them,” the author noted, “that people were breathing less air.” According to a 1997 USDA report, in 1970 sucrose accounted for about 83% of sweeteners Americans ate, but by 1997 sucrose was only about 43%. High fructose corn syrup made up virtually the rest, or about 56% of the sweeteners that Americans consumed in 1997

On a recent trip to Cargill’s Eddyville, Iowa, sweeteners plant, an RFR and I watched as tens of acres worth of corn every hour was being converted in their monstrously large plant to corn sweetener. According to some rough calculations, which I at first thought must be mistaken but in fact is probably close to the truth, it seems that the Cargill plant produces every day enough high fructose corn syrup to sweeten 30 million cans of soda. And the Eddyville plant is only one of several corn sweeteners plants that the OU certifies around the country.

Of course, this is not the kind of thing we were thinking about in Eddyville – we were there to review the kashrus of the high fructose corn syrup that Cargill was producing, which may be going into the soda pop that many of us our drinking. Which brings up a new question: how kosher sensitive is glucose isomerase, or some of the other ingredients used to produce high fructose corn syrup? That question will be addressed in the next issue of IAR Ingredients Dispatch.


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