Corn syrup is one of several natural sweeteners derived from corn starch. It is used in a wide variety of food products including cookies, crackers, catsups, cereals, flavored yogurts, ice cream, preserved meats, canned fruits and vegetables, soups, beers, and many others. It is also used to provide an acceptable taste to sealable envelopes, stamps, and aspirins. One derivative of corn syrup is high fructose corn syrup, which is as sweet as sugar and is often used in soft drinks. Corn syrup may be shipped and used as a thick liquid or it may be dried to form a crystalline powder.
The use of corn as a food product dates to about 4000 B.C. when it was grown near what is now Oaxaca in Mexico. Because of its natural hardiness, corn was successfully cultivated by people in much of the Western Hemisphere. It was imported to Spain from the West Indies in about 1520 A.D. and soon became a popular food throughout Europe.
As the use of corn as a food product spread, various machines were developed to help process it. Water-powered mills, which had been used to grind wheat and other grains for thousands of years, were adapted to grind dried corn. By the early 1700s, a device to shell corn—remove the dried corn kernels from the cob—had been patented. The refining process used to separate corn starch from corn kernels is called the wet milling process. It was patented by Orlando Jones in 1841, and Thomas Kingsford established the first commercial wet milling plant in the United States in 1842. The process for converting starches into sugars was first developed in Japan in the 800s using arrowroot. In 1811, the Russian chemist G.S.C. Kirchoff rediscovered this process when he heated potato starch in a weak solution of sulfuric acid to produce several starch-derived sweeteners, including dextrose. In the United States, this acid conversion method was adapted to corn starch in the mid-1800s and the first corn sweeteners were produced in a plant in Buffalo, New York, in 1866. This process remained the principal source of corn syrup until 1967, when the enzyme conversion method for producing high fructose corn syrup was commercialized. At first, this was a batch process requiring several days. In 1972, a continuous enzyme conversion process was developed that reduced the time to several minutes or hours.
Today,corn syrups are an important part of many products. In 1996, there were 28 corn-refining plants in the United States that processed a total of about 72 billion lb (33 billion kg) of corn. Of that amount, about 25 billion lb (11.4 billion kg) were converted into corn syrups and other corn sweeteners. These corn-based products supplied more than 55% of the nutritive sweetener market in the United States.