Wow, how'd we all miss that? (Articles I looked up said it was "almost all glucose" but didn't give a specific figure.) So it sounds like there actually are plant sugars containing no fructose. Of course, in corn, they occur naturally as starches, glucose polysaccharides, which must be hydrolyzed to produce corn syrup.

So dextrose (D-glucose, the only form of glucose that the body can metabolize) is the same as "corn syrup solids." That's what Ruhlman & Polcyn recommend for meat cures - when you put it that way it doesn't sound quite so bad.

Another thing I had forgotten is that sucrose is actually a disaccharide - a molecule of glucose and a molecule of fructose bonded together. Glucose-fructose syrup, of which HFCS is one, is different because the molecules are already separate and do not require the body to break them down with sucrase.

It turns out that when HFCS is made, it's often produced at a strength of 90% fructose. It's then mixed with regular corn syrup to produce HFCS-55.