Wednesday, September 15, 2010

High Fructose Corn Syrup

Corn is mainly a starch crop, and starch is a glucose polymer. When corn starch is converted to corn syrup, it's almost 100% glucose, with almost no fructose.

There's a chemical reaction that can be employed at industrial scales to convert glucose to fructose (the two are isomers of each other, but not chemically identical). High Fructose Corn Syrup is made by mixing corn syrup (almost 100% glucose) with fructose converted from corn syrup. Typical commercial HFCS is 55% fructose, 45% glucose (called HFCS55, other mixes are also available).

Fructose is sweeter than glucose or sucrose, so much less HFCS is needed to sweeten a product than corn syrup, and less HFCS is needed than sucrose (but not as much less).

Sucrose is a molecule formed by combining one molecule of glucose with one molecule of fructose. Under many common conditions (heat, acid, certain digestive enzymes) it breaks into glucose and fructose in equal amounts. The body cannot absorb sucrose directly; it must be broken down into glucose/fructose first. It's been shown [citation needed] that even in short time frames (like 2 weeks) most of the sucrose in a can of cola will break down into effectively HFCS50 in the can.

No real evidence has been shown of a difference in metabolism of HFCS50 v. sucrose. The only potentially plausible method of action for any differences in metabolism is the idea that HFCS50 doesn't require digestion before absorption, so the sugar hits you as a spike rather than over time. But sucrose is broken down quickly.

There are studies which compare dietary intake of pure fructose with dietary intake of pure glucose or of sucrose which do seem to show that pure fructose is a bad dietary choice (at least, if you're a rat or mouse, of course), but the bad effects don't show up when fructose and glucose are both in the diet.

Honey is approximately equivalent (in sugar content) to HFCS55, Agave syrup to somewhere between HFCS56 and HFCS92, depending on the source you read. Maple syrup is mostly sucrose.

HFCS is king in the US because of two lobbying efforts by two different agricultural industries. The relatively small US Sugar industry asked for tariffs to drive up the price of imported sugar so that they could make a profit. They got the tariffs. The relatively humongous corn industry asked for subsidies so that they could make a profit. They got their subsidies. As such, HFCS42 costs US$0.26/lb in the wholesale market, and refined beet sugar in the same markets costs US$0.59/lb.

But the main reason why HFCS is villified is because it's not "natural".
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3 comments:

  1. Corn industry propaganda. The internet is also "not'natural'".

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  2. Honey, chill. This just in HFCS is being "rebranded" as "Corn Sugar"
    Still smells like shit to me

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