Dextrose equivalent

Dextrose equivalent (DE) is a measure of the amount of reducing sugars present in a sugar product, relative to glucose, expressed as a percentage on a dry basis. For example, a maltodextrin with a DE of 10 would have 10% of the reducing power of dextrose (DE = 100), while sucrose, with a DE of 120, would have 1.2 times the reducing power. For solutions made from starch, it is an estimate of the percentage reducing sugars present in the total starch product.

In all glucose polymers, from the native starch to glucose syrup, the molecular chain begins with a reducing sugar, containing a free aldehyde. As the starch is hydrolysed, the molecules become shorter and more reducing sugars are present. Because different reducing sugars (e.g. fructose and glucose) have different sweetness, it is incorrect to assume that there is any direct relationship between DE and sweetness.

The DE describes the degree of conversion of starch to dextrose:

• starch is close to 0,
• glucose/dextrose is 100 (percent),
• dextrins varies between 1 and 13,
• maltodextrins varies between 3 and 20
• glucose syrups contain a minimum of 20% reducing sugars.

The DE gives an indication of the average degree of polymerisation (DP) for starch sugars. The rule of thumb is DE X DP = 120. The standard method of determining DE is the Lane-Enyon titration, based on the reduction of Copper(II) sulfate in an alkaline tartrate solution,^[1]p.230 an application of Fehling's test.

References

1. ^ Dziedzic, S. Z.; Kearsley, M. W. (1995). Handbook of starch hydrolysis products and their derivatives. London: Blackie Academic & Professional. ISBN 0-7514-0269-9.