Dextrose equivalent
The dextrose equivalent ( DE, for English dextrose equivalent) of a polysaccharide mixture indicates the mass percentage of reducing sugars (calculated as glucose) in the dry matter. It corresponds to the mass of glucose ( = dextrose), which would have the same reducing power per 100 g of dry matter. The DE value is a measure of how far the polymer degradation has occurred, thus obtained products with a low DE value a large proportion of polysaccharides, and a low content of low molecular sugars, whereas products having a high DE value mainly consist of low molecular weight sugars.
The dextrose equivalent of starch is 0, the glucose 100 The maltodextrin, depending on the degree of hydrolysis of 3 to 20 products with DE values greater than 20 glucose syrups are attributed.
With a higher DE value taking the following properties:
- Sweetening power
- Solubility
- Hygroscopicity
- Osmolality
- Lowering the freezing point of
Determination
The determination of the dextrose equivalent by the European Pharmacopoeia uses the reactions of the Fehling's test and the method of titration. The test sample solution is added dropwise with a burette to a Fehling's reagent, ie alkaline to a Cu2 ion - containing solution. The reducing sugars present in the sample solution has been added dropwise added while the Cu2 ions to brick-red, solid copper (I ) oxide, which settles. The first drop of excess sample solution, for which no equivalent amount of Cu2 ions is present more in Fehling's reagent, reduced blue methylene blue to a colorless product ( leuco form of methylene blue). The redox indicator methylene blue is thereby added to the Fehling reagent prior to the start of the titration. At the transition point so a color change from blue to colorless instead. For the evaluation, an inversely proportional relationship applies: the consumption of sample solution, the higher to the transition point, the lower the content of reducing sugars.
- Measured variable ( Food Technology )
- Diabetology