I thought I would start with a simple visual, a flowchart of corn! At the top of our flowchart we find corn. Plain old boring yellow corn, I'm sure you've heard of it. The first stop on the flowchart brings us to cornstarch or corn flour, depending on where you live. Cornstarch is obtained from corn via a process of wet milling. Basically the corn is soaked, ground and the natural starch is extracted from the mixture. Once dried, you have a bright, white cornstarch. You use it to thicken sauces, make soft cookies, all sorts of things.
Cornstarch can be further changed into corn syrup by the action of hydrolysis. Hydrolysis means that you add water molecules to the cornstarch and break it down into smaller sugar molecules, specifically glucose. Corn syrup is also called glucose syrup in some parts of the world. Most Americans can find this at the grocery store under the brand of Karo - Light Corn Syrup. (Light refers only to the color of the syrup, not the calorie count) You use this in candy making and baking to add volume & soften texture.
This is where it gets a little tricky and controversial. Corn syrup can be treated with an enzyme called glucose isomerase to convert some of the glucose to fructose. The product of this is the dreaded High fructose corn syrup. The most common form of HFCS contains 55% fructose, 45% glucose (and a tiny percentage of other sugars).
I know, it can be a little confusing. Especially since sucrose, table sugar, is also made up of one fructose and one glucose molecule! So why do we see HFCS in everything? Two reasons - Money & your Sweet Tooth.
Money - Sugar costs more than corn. A whole lot more. Even after you put corn through all those manufacturing processes, corn syrup still costs less than table sugar! To keep their costs down, manufacturers of snack cakes, ice creams, sodas & cereals use HFCS to sweeten their products.
Your Sweet Tooth - If manufacturers simply substituted the sugar with natural corn syrup, the products wouldn't be as sweet. Americans love sweet things and when it comes to sugars - not all sugars have the same sweetness. If we randomly set the sweetness of table sugar to 1.00, the rest of the common sugars rate as follows...
0.70 = glucose (corn syrup)
1.00 = sucrose (table sugar)
1.30 = fructose (fruit sugar)
So to maintain the same sweetness level, but keep costs low, manufacturers use the sweeter HFCS in place of sugar and regular corn syrup.
There we have it, the differences between all these corn products are a few water molecules and some chemical bonds. What's my opinion on HFCS? Personally, I try to avoid it. I just don't eat processed foods that often and don't drink soda at all. I don't think a small amount of HFCS in your diet will lead to life-threatening consequences. If you want to read an extremely well researched article on the fructose hypothesis, check this one out!
A whole other question about corn syrup comes up when discussing GMO's (Genetically Modified Organisms). Over 90% of corn in the US is GMO, so the majority of corn syrup produced here is made from GMO corn. However, there is no way that corn starch from GMO corn is any different from corn starch from non-GMO corn, because chemically they are both pure amylopectin.
If you are on the side of anti-GMO, but you still want to make candy at home, you have a simple option! I suggest buying Pastry 1 - Glucose Syrup. It is made from non-GMO wheat!
Have any questions about corn syrup or HFCS that I have neglected to answer? Drop your question in the comment section and I'll be doing a follow up next month!