Dextrose equivalent determination

These are some examples of the use of i.r. spectra in the analysis and identification of carbohydrates in foods and natural products. Very often, these spectroscopic techniques are complementary to others, such as the study of aldobiouronic acids obtained by hydrolysis of peach-gum polysaccharides by their optical rotations and their i.r. spectra.100 However, the i.r. results appear to be sufficiently reliable to be used in the detection of traces of fructose and glucose, and to determine the d.e. (dextrose equivalent) of corn syrups, as well as the quantitative carbohydrate content in different products.101... 

Specificity is a property of monocomponent systems and it occurs when the method is free of interference. Selectivity is related to the complexity of the matrix and it occurs when not more than one ion (molecule) interferes in determination. Enantioselectivity is a relatively new term introduced for the assay of enantiomers.257258 An analytical method is enantioselective when it can discriminate between enantiomers. Enantiospecificity is an extreme case of enantioselectivity. It is possible to create the conditions for a highly enantioselective analysis, and in this case enantiospecificity can also occur. For example, a maltodextrin with dextrose equivalence (DE) of 4.0 to 7.0 was used in capillary zone electrophoresis as a stationary phase for the separation of the enantiomers,259 and also in the design of a potentiometric, enantioselective membrane electrode.260 The method for capillary zone electrophoresis is enantioselective, as it is for the potentiometric method. 

To examine the solubility of starch, a maltodextrin with a low dextrose equivalent of 5 was dispersed in a series of alcohol solutions at different concentrations. After filtration, the solubilized fractions were injected onto size-exclusion columns to determine maximum relative molecular mass M The results in... 

Dextrose equivalent (DE) An expression of the extent of hydrolysis of starch to glucose. It is measured by determining the reducing sugar content of syrup. Pure... 

Hexabioses.—Maltose.—Almost the sole occurrence of this sugar is in the product of the hydrolysis of starch either by the action of enzymes or by acid hydrolysis. It is not isolated but is fermented in the solution in which it is prepared. The enzyme, maltase, is usually elaborated by the same yeasts as carry on the fermentation. This enzyme converts the maltose into two equivalents of dextrose which are then directly fermentable. When isolated, maltose forms hard white crystalline masses, very similar to grape sugar. It is determinable by the facts that its solutions have some reducing power (about two-thirds that of glucose), and that its solutions are strongly dextro-rotary. 

By the action of acids or invertase, sucrose is converted to a mixture of equal parts of dextrose and laevulose (inversion) if the optical rotation of any mixture containing sucrose is determined before and after inversion, the change of rotation observed is equivalent to the quantity of sucrose present, and by simple calculation the proportion may be ascertained. 

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