Sugar

As a chemical term, “sugar” usually refers to all carbohydrates of the general formula C_n(H₂O)_n. Sucrose is a disaccharide, or double sugar, being composed of one molecule of glucose linked to one molecule of fructose. Because one molecule of water (H₂O) is lost in the condensation reaction linking glucose to fructose, sucrose is represented by the formula C₁₂H₂₂O₁₁ (following the general formula C_n[H₂O]_{n − 1}).

Sucrose is found in almost all plants, but it occurs at concentrations high enough for economic recovery only in sugarcane (Saccharum officinarum) and sugar beets (Beta vulgaris). The former is a giant grass growing in tropical and subtropical areas; the latter is a root crop growing in temperate zones. Sugarcane ranges from 7 to 18 percent sugar by weight, while sugar beets are from 8 to 22 percent sugar by weight. Sucrose from either source (or from two relatively minor sources, the sugar maple tree and the date palm) is the same molecule, yielding 3.94 calories per gram as do all carbohydrates. Differences in sugar products come from other components isolated with sucrose.