The Relationship Of Corn Starch To High-fructose Corn Syrup

Cornstarch is a plant carbohydrate used commercially in the manufacture of foods and drugs, paper products and animal feeds. High-fructose corn syrup is a food product made from cornstarch that serves as a sweetening agent in the food and beverage industry. Nutritional differences between the two exist. Additionally, controversy exists over the health implications of high-fructose corn syrup consumption.

Corn Starch

Starch, a large molecule comprising glucose units bound together in a branched configuration, provides a nutritional reserve for a variety of plants. Corn, for example, contains roughly 60 percent starch by weight. In commercial manufacture, cornstarch is separated from the rest of the corn kernel by first steeping the corn in hot water to soften the starch granules. Once the germ of the kernel is removed, the milling process grinds the remaining kernel to release the softened starch molecules, which are then filtered, washed and dried to create a purified cornstarch product. More than 50 percent of commercially produced cornstarch serves as a precursor to high-fructose corn syrup, according to the International Starch Institute.

High-Fructose Corn Syrup

In the manufacture high-fructose corn syrup, enzymes and chemicals – such as amylase and hydrochloric acid – break down molecules of cornstarch to release glucose. An enzyme called glucose isomerase then converts the bulk of the glucose molecules to fructose. The resulting product, known as HFCS-90, contains 90 percent fructose and 10 percent glucose. Manufacturers combine HFCS-90 with pure glucose syrup to create HFCS-55 and HFCS-42, with 55 percent and 42 percent fructose, respectively. Because fructose tastes sweeter than other sugars, and because cornstarch is relatively cheap, both HFCS-55 and HFCS-42 are common additives in processed foods.

Nutrition

High-fructose corn syrup contains more water by weight than cornstarch and therefore offers fewer nutrients per 100-gram serving. For example, 100 grams of cornstarch contains 380 calories compared to 280 for high-fructose corn syrup. This quantity of cornstarch gives you more than 90 grams of carbohydrates, all as starch, with a small amount of protein and fiber. The same volume of high-fructose corn syrup provides 76 grams of carbohydrate, one-third of which is sugar, with no protein and no fiber.

Controversy

Sucrose, or table sugar, consists of one glucose molecule bound to one fructose molecule. HFCS-55, derived from cornstarch and a common ingredient in sweetened beverages, tastes sweeter than sucrose because of both its higher fructose content and the fact that fructose in high-fructose corn syrup is more immediately available than fructose bound up in a sucrose molecule. High-fructose corn syrup consumption has been implicated in the growing incidence of obesity due to concerns about the way your body metabolizes fructose compared to other sugars. However, because high-fructose corn syrup is so chemically similar to sucrose, the rise of obesity associated with high intakes of this cornstarch derivative is likely due to overconsumption of all types of sweeteners rather than an inherent property of high-fructose corn syrup, according to “Consumer Reports Health.”