Sugar is simply separated from the beet or cane plant, and the result is 99.95% pure sucrose (sugar). The sucrose from sugar beets and sugar cane is not only identical to one another, but each is the same as the sucrose present in fruits and vegetables.
But I've come across some contradictory statements in a different book. I've been reading Bi-Rite Market's Eat Good Food: A Grocer's Guide to Shopping, Cooking & Creating Community Through Food and learning a lot about buying food. The book is very anti-GMO. In the section on sugar, it says.
Beet sugar falls short in multiple ways: it does not melt as smoothly or caramelize as readily, and in baked goods it produces inferior texture and flavor. For the best flavor, texture, and overall quality, buy sugar that specifically states "pure cane sugar" on the package.
I suppose the difference between commercial pure cane sugar and beet sugar must be due to processing if once we get it down to sucrose it is identical. Anyone have experience with using "pure cane sugar" vs regular granulated sugar? Maybe I should visit the store.
Furthermore the Bi Rite book asserts sugar beets are almost always GMO, and any conventional sugar is typically heavily sprayed with pesticides and other chemicals. (Yet that must mean American sugar beets, as there are restrictions on GMO products in Europe.) Thus they recommend buying organic sugar (except when using it to make candy as granulated is better for this).
Sugar: it turns out there is a lot to know.