Sugar, Sugar, Everywhere--the many names and kinds of sugars in our food

Years ago, a woman at my daughter’s daycare commented favorably regarding some sort of fruit-leather-ish snack, “And it doesn’t have any sugar.” At the time, I thought, “I seriously doubt that,” suspecting she just hadn’t recognized some form of sugar in it. Unfortunately, it wasn’t a good moment to delve into the actual ingredients and discover just what sort of sugar was actually involved, so I let it pass.

To be fair, sugars come in so many varieties and are known by so many names (sometimes the same sugar has more than one name) that it’s hard to keep up with them all. So I’ve been doing a little research (mostly online) so I can present a list of different kinds of sugars and a little information on each, as well as some information on common sweeteners such as honey and corn syrup.

First, there are the simple sugars. I’m not a chemist and this isn’t meant to be a chemistry lesson, so I’m just going to say that the simple sugars we’re interested in have six carbon atoms and some hydrogen and oxygen atoms in various configurations, and other sugars are built from them. The simple sugars we typically hear about or see listed are the following:

Glucose: Diabetics have to keep track of the levels of glucose in their blood. Glucose that is added to foods sometimes goes by the name of “dextrose”. Glucose is somewhat less sweet than sucrose, apparently.*

Dextrose: See glucose.

Fructose: Known as fruit sugar, it is commonly found in fruits, but is also used as a sweetener sometimes. Sweeter than sucrose.

Galactose: I’m listing this one mostly because it is a component of lactose. Less sweet than sucrose.

Second, there are the disaccharides, which are sugars made up of two simple sugar molecules bonded together. Here are some of interest:

Sucrose (white sugar, table sugar): Made of a glucose molecule bonded to a fructose molecule.

Lactose (milk sugar): One glucose molecule bonded to one galactose molecule. Some people no longer have enough of the enzyme to break it down, in which case the lactose gets used by bacteria much farther down the intestinal tract with uncomfortable results. Lactose is apparently only mildly sweet, which maybe explains why lactose-free milk (in which the lactose has been broken down into glucose and galactose) tastes sweeter than regular milk.

Maltose: one glucose bonded to one glucose. Maltose is apparently significantly less sweet than sucrose, but sweeter than lactose. I should add that the properties of substances made of two or more sugars depends a lot on how the sugar molecules are bonded together—longer chains of glucose, depending on length and kind of bond, can be starches or cellulose. More on those later.

Alpha-gal: One galactose molecule bonded to another galactose molecule. Some people have a tick-bite induced allergy to alpha-gal, and react to beef and other meat from mammals. As far as I know, alpha-gal doesn’t get used as a sweetener and I have no idea if it tastes sweet.

Finally, there are longer chains of sugar molecules. In particular, there are starches and cellulose.

Starches are long chains of glucose molecules. Our bodies can break these down into glucose when we eat them.

Cellulose, on the other hand, we cannot break down. Cellulose molecules are very VERY long chains of glucose. They are found in plants and help give them structure. They also provide us with “fiber” as they go right through our system. Cows, rabbits, termites and other animals that have a diet heavy in grass (or wood)  have systems that can break down cellulose. I think most of these systems involve special bacteria.

So what sugars are actually in the various alternative sweeteners out there? I had to look this up, as I have never really been sure what is in honey or maple syrup, let alone agave syrup.

Honey: Apparently it contains both glucose and fructose, but separate from each other, not bonded together to form sucrose. At least, that was my understanding from what I read.

Maple syrup: Sucrose. Okay, that’s simple.

Corn syrup (not high fructose corn syrup, but Karo corn syrup that you cook with): Glucose. It sounds like this is roughly the same as the “glucose syrup” that shows up in British recipes.

High-fructose corn syrup: This is the one that gets added to a lot of processed foods. It contains both glucose and fructose. Hmmm, does that make HFCS a lot like honey, except for the flavor? Or does honey contain other interesting things that change how it affects us? I do not know. They sound pretty similar, sugar-wise. Another interesting thing: The HFCS industry is trying to persuade people that since high-fructose corn syrup contains the same molecules as sucrose, they should be no more concerned about it than they are about sucrose. But since how molecules are bonded together sometimes makes a difference in how they affect us, I’m suspicious of this reasoning.

Agave syrup: Apparently this is very high in fructose.

Also, concentrated pear juice and concentrated grape juice are sometimes added to foods for the purpose of sweetening them. These may have high levels of fructose.

I didn’t list stevia because it is something else entirely and not made of sugars.

To repeat, I’m not a chemist (I took organic chemistry in college, but that was more years ago that I care to admit). So if I have said something misleading by mistake, please comment with a correction.

Till next post.

 *I wasn’t able to find out if the comparisons of sweetness were weight-for-weight, or by volume (unlikely) or for comparable concentrations of molecules. I don’t think this information is very useful without knowing this. I’m guessing it was weight-for-weight.