Dextrose equivalent
| Carbohydrate | Dextrose Equivalent |
| Starch | ~0% |
| Dextrins | 1–13% |
| Maltodextrins | 3–20% |
| Glucose syrups | ≥20% |
| Dextrose (glucose) | 100% |
Dextrose equivalent is a measure of the amount of reducing sugars present in a sugar product, expressed as a percentage on a dry basis relative to dextrose. The dextrose equivalent gives an indication of the average degree of polymerisation for starch sugars. As a rule of thumb, DE × DP = 120.
In all glucose polymers, from the native starch to glucose syrup, the molecular chain ends with a reducing sugar, containing a free aldehyde in its linear form. As the starch is hydrolysed, the molecules become shorter and more reducing sugars are present. Therefore, the dextrose equivalent describes the degree of conversion of starch to dextrose. The standard method of determining the dextrose equivalent is the Lane-Eynon titration, based on the reduction of copper(II) sulfate in an alkaline tartrate solution, an application of Fehling's test.
Examples:
- A maltodextrin with a DE of 10 would have 10% of the reducing power of dextrose which has a DE of 100.
- Maltose, a disaccharide made of two glucose molecules, has a DE of 52, correcting for the water loss in molecular weight when the two molecules are combined. Glucose has a molecular mass of 180, while water has a molecular mass of 18. For each 2 glucose monomers binding, a water molecule is removed.
- Sucrose actually has a DE of zero even though it is a disaccharide, because both reducing groups of the monosaccharides that make it are connected, so there are no remaining reducing groups.
Uses
Dextrose equivalent is used to understand how different sugar products will affect:- Crystallization prevention
- Viscosity
- Water activity
- Sweetness
- Caramelization