What is High Fructose Corn Syrup HFCS?
HFCS is a mixture of glucose, maltose, and fructose. Corn syrup itself does not contain any fructose, the fructose is added to corn syrup to make HFCS.
How is Corn Syrup Made?
The original method used since 1911 was to treat corn starch with hydrochloric acid which broke down the starch into glucose and maltose, then the acid was neutralized with sodium hydroxide which created sodium chloride from the acid (table salt). Having two different sugars in corn syrup prevents it from crystalizing thus producing a syrup.
A second method and the one which used commonly is to treat the starch with an enzyme called amylase resulting in primarily glucose and maltose. There is no fructose in corn syrup. An example of ordinary corn syrup is Karo Light (Not Lite) Corn Syrup.
How is Fructose made?
Fructose is made by the addition of another enzyme called D-Xlyose isomerase resulting in primarily fructose.
The fructose is then blended with corn syrup producing high fructose corn syrup (HFCS)
There are two types of HFCS authorized for foods in the USA, HFCS-42 and HFCS-55. HFCS-42 contains 42% fructose while HFCS-55 contains 55% fructose. Ordinary table sugar (sucrose) is 50% fructose. HFCS-42 is used in foods while HFCS-55 is used in beverages.
Since fructose is much sweeter than sucrose, HFCS-55 requires less to be used in beverages resulting in about the same amount of total sugar which also means less glucose in the beverage. This would be a good thing since it would contain less calories. Knowing this, why is HFCS vilified.
Food processors also use HFCS-42 because its a liquid and more easily measured and added to foods than sucrose, and is actually healthier than sucrose.
Certainly consuming large amounts of fructose is not healthy, as it must be metabolized by the liver. The liver metabolizes the fructose using the same metabolic pathways as it uses to metabolize alcohol. As such, it contributes to fatty liver disease, which is becoming more prevalent in children and young people who do not consume alcohol.
The glycemic index of HFCS is listed in different places as being between 50 and 73, while table sugar (sucrose) has a gycemic index of 103.
But avoiding HFCS is not the answer, as it is not significantly better than consuming foods and beverages which use sucrose as a sweetener. due to its lower glycemic index. Better is to avoid any kind of sugar.
So why is HFCS demonized? Perhaps this is done by the sugar industry itself or is another attack on the corn itself. I do not know.