More about high fructose corn syrup


High fructose corn syrup contains both fructose and glucose, commonly in a ratio of 55% fructose to 45% glucose. It is "high fructose" only in comparison to plain corn syrup, which is 100% glucose and no fructose.
High fructose corn syrup is produced from corn starch. Starch is a polymer made of glucose molecules linked into long chains. Corn starch is first treated with the enzymes alpha-amylase and glucoamylase. These break the starch down to glucose. The glucose is then treated with another enzyme, glucose isomerase, that can reversibly convert glucose to fructose. At the end of this step, the mixture usually contains about 42% fructose and 58% glucose. A separation step produces a syrup containing about 90% fructose, and this can be blended with the 42% fructose material to make the 55% fructose syrup that is widely used in beverage manufacture.


There has been much hype recently surrounding the idea that high fructose corn syrup is the cause of an obesity epidemic. This is based on a rough correlation between the rise in obesity and increased usage of high fructose corn syrup over the past twenty or thirty years. But the same rise in obesity has occured in Europe, Australia, and parts of South America, regions where high fructose corn syrup is not widely used. A recent review of the scientific literature on this subject concluded that "HFCS does not appear to contribute to overweight and obesity any differently than do other energy sources."[Forshee, R.A.; Storey, M.L.; Allison, D.B.; Glinsmann, W.H.; Hein, G.L.; Lineback, D.R.; Miller, S.A.; Nicklas, T.A.; Weaver, G.A.; White, J.S. A critical examination of the evidence relating high fructose corn syrup and weight gain. Critical Rev. Food Sci. Nutr. 47:561-582 (2007)] Obesity is caused by overconsumption, whether the substance being overconsumed is sucrose, high fructose corn syrup, or any other calorie-containing substance.