Judith Kennedy - posted on 02/11/2009 ( 2 moms have responded )
How High Fructose Corn Syrup is made and then metabolized.
High-fructose corn syrup (HFCS) is produced by processing corn starch to yield glucose, and then processing the glucose to produce a high percentage of fructose. But there is a little more to it. This is the modus operandi of the food conglomerates--break down commodities into their basic components and then put them back together again as processed food. Read further.
1.Specific amino acids in the enzyme alpha-amylase are genetically modified and either changed or replaced so the enzyme's "backbone" won't break down or unfold.
2.Alpha-amylase is industrially produced by a bacterium, usually Bacillus sp. It is purified and then shipped to HFCS manufacturers.
3.Cornstarch is treated with alpha-amylase to produce shorter chains of sugars called polysaccharides.
4.Unlike alpha-amylase, glucoamylase is produced by Aspergillus, a fungus, in a fermentation vat where one would likely see little balls of Aspergillus floating on the top.
5.Next, the enzyme called glucoamylase breaks the sugar chains down even further to yield the simple sugar glucose.
6.Again, specific amino acids in another enzyme, glucose-isomerase, are genetically modified and either changed or replaced so the enzyme's "backbone" won't break down or unfold.
7.While alpha-amylase and glucoamylase are added directly to the slurry, pricey glucose-isomerase is packed into columns and the sugar mixture is then passed over it. This third enzyme, converts glucose to a mixture of about 42 percent fructose and 50-52 percent glucose with some other sugars mixed in.
8.A liquid chromatography step takes the mixture to 90 percent fructose.
9.Finally, this is back-blended with the original mixture to yield a final concentration of about 55 percent fructose--what the industry calls high fructose corn syrup.
"The medical profession thinks fructose is better for diabetics than sugar," says Dr. Meira Field of the USDA, "but every cell in the body can metabolize glucose. However, all fructose must be metabolized in the liver. The livers of a study (giving some rats glucose and some fructose) using rats on the high fructose diet looked like the livers of alcoholics, plugged with fat and cirrhotic."