Sugar and spice and everything nice
Somebody over on Facebook asked me a question about Splenda today, and it got me thinking, saaaaaay. This might be a good topic for those Posts of Science Goodness that you guys seem to enjoy.
Today's topic: sweeteners! With extra special chemistry mojo!
Okay. First things first. The original sweetener. This is sucrose, otherwise known as table sugar:
Notice that it's made of two pieces. The piece on the right, the six-membered-ring piece, that's glucose. The piece on the left, the five-membered ring, that's fructose. They're both monosaccharides, so sucrose is a disaccharide. Glucose, of course, is the body's main source of energy, which it obtains by digesting carbohydrates (like sucrose) and breaking them down to release the glucose. Incidentally, glucose and dextrose are the same thing. Every sugar has two three-dimensional forms. Glucose comes as D-glucose and L-glucose, which are identical except they're mirror images of each other. Only D-glucose occurs in nature and is referred to as "dextrose." L-glucose has to be made artificially and is much rarer.
Now the non-sugar sweeteners.
Aspartame:
Note that it does not look at all like sucrose. In fact it isn't a carbohydrate at all. It is, in fact, made of amino acids. Technically it's a dipeptide. It's two amino acids joined together. On the left is aspartic acid, and on the right is phenylalanine. Both are amino acids, you know, those infamous "building blocks of proteins" we all learned about in biology class.
Saccharine:
Saccharine looks totally different from both sugar AND aspartame. It differs from aspartame in that while aspartame is synthesized, saccharine was discovered as a natural component of...well, nature (it was isolated from coal tar, believe it or not). It's a LOT sweeter than sugar and it's cut down considerably when it's used as a sweetener.
Now, here's Splenda, whose chemical name is sucralose:
Note that is virtually identical in chemical structure to sucrose (really it is, this picture is just flipped and rotated some from the sucrose picture. I could draw it for you so you could see their similarity better but these pictures were the ones I found on the Tubes). The difference is that it's based on a slight variation of sucrose called galactosucrose, and three of the -OH groups have been replaced by -Cl atoms.
That's it. That's the difference. They're so similar that if sweeteners were men's suits, Splenda would be wearing a light blue tie instead of a dark blue tie. Whereas aspartame would be wearing jeans and a t-shirt, and saccharine would be wearing one of those Borat men's thong bathing suits.
Now, small differences in structure CAN mean big differences in biological activity. I'm not going to get into any assertions about the safety of artificial sweeteners. There's some evidence that some people may have aspartame sensitivity, much as some people have MSG sensitivity, which is more on the lines of an allergy than a side effect. There's also some who contend that the sweetness of non-sugar sweeteners triggers insulin release and causes weight gain...but just as many studies which show no such effect. It's still being investigated.
Today's topic: sweeteners! With extra special chemistry mojo!
Okay. First things first. The original sweetener. This is sucrose, otherwise known as table sugar:
Notice that it's made of two pieces. The piece on the right, the six-membered-ring piece, that's glucose. The piece on the left, the five-membered ring, that's fructose. They're both monosaccharides, so sucrose is a disaccharide. Glucose, of course, is the body's main source of energy, which it obtains by digesting carbohydrates (like sucrose) and breaking them down to release the glucose. Incidentally, glucose and dextrose are the same thing. Every sugar has two three-dimensional forms. Glucose comes as D-glucose and L-glucose, which are identical except they're mirror images of each other. Only D-glucose occurs in nature and is referred to as "dextrose." L-glucose has to be made artificially and is much rarer.
Now the non-sugar sweeteners.
Aspartame:
Note that it does not look at all like sucrose. In fact it isn't a carbohydrate at all. It is, in fact, made of amino acids. Technically it's a dipeptide. It's two amino acids joined together. On the left is aspartic acid, and on the right is phenylalanine. Both are amino acids, you know, those infamous "building blocks of proteins" we all learned about in biology class.
Saccharine:
Saccharine looks totally different from both sugar AND aspartame. It differs from aspartame in that while aspartame is synthesized, saccharine was discovered as a natural component of...well, nature (it was isolated from coal tar, believe it or not). It's a LOT sweeter than sugar and it's cut down considerably when it's used as a sweetener.
Now, here's Splenda, whose chemical name is sucralose:
Note that is virtually identical in chemical structure to sucrose (really it is, this picture is just flipped and rotated some from the sucrose picture. I could draw it for you so you could see their similarity better but these pictures were the ones I found on the Tubes). The difference is that it's based on a slight variation of sucrose called galactosucrose, and three of the -OH groups have been replaced by -Cl atoms.
That's it. That's the difference. They're so similar that if sweeteners were men's suits, Splenda would be wearing a light blue tie instead of a dark blue tie. Whereas aspartame would be wearing jeans and a t-shirt, and saccharine would be wearing one of those Borat men's thong bathing suits.
Now, small differences in structure CAN mean big differences in biological activity. I'm not going to get into any assertions about the safety of artificial sweeteners. There's some evidence that some people may have aspartame sensitivity, much as some people have MSG sensitivity, which is more on the lines of an allergy than a side effect. There's also some who contend that the sweetness of non-sugar sweeteners triggers insulin release and causes weight gain...but just as many studies which show no such effect. It's still being investigated.