In carefully controlled studies with good statistical treatment, objective measures of sweetness can be obtained. However, there are many factors that influence the result. Therefore, figures stated in literature show some variance. Influencing factors may range from concentration, temperature and other saccharides to the type of flavor system used in the application, etc.
Sucrose is usually regarded as the reference material against which other sweeteners are compared. When making such comparisons, the most common measurement invoked is “relative sweetness”. It is defined as the ratio of concentrations of sweetener solutions that are observed to possess equal intensity of sweetness. The sweetness level set for sucrose is 100.
In applications, consideration of both flavor masking and flavor enhancement should be taken into account. As an example, fructose has a higher initial intensity of sweetness than sucrose, but it will fade away more rapidly.
As a consequence, other flavors in the system will be perceived more clearly after the peak of the sweetness decreases.
Non-enzymatic browning (Maillard reaction)
The desired browning effect in certain food applications is achieved through a condensation reaction between amino compounds and reducing sugars resulting in the formation of melanoid pigments. With the choice in saccharide pattern, the strength of the Maillard reaction can be controlled.
Fermentability is determined by the availability of fermentable sugars, dextrose being 100 percent fermentable. The applications in which fermentability is used most are in bakery and the beer brewing segments. The advantage of glucose syrups is the possibility of modifying the degree of fermentation and the speed at which the sugars are fermented.
Hygroscopicity and water activity
Hygroscopicity is a measure of moisture absorption ability. Hygroscopicity is important for shelf-life as it influences enzymatic activity, the Maillard reaction, fat oxidation and microbial stability.
Hygroscopicity and water activity reflect how an ingredient or application will “deal” with water.
Inhibition of crystallization
All starch hydrolysates exert an influence on the crystallization of sweeteners in solution. Crystal formation is directly related to the saturation points of the various substances in solution. These are largely determined by molecular weight, temperature and the presence of other substances that may lower or raise total solubility and the mobility of molecules of the saccharide e.g. sucrose, in order to form the crystal. The important characteristic of glucose syrup is the ability to inhibit crystallization.
Freezing point depression factor (FPDF)
The effect of freezing point depression is related to the molecular weight and the effect increases toward the monosaccharide dextrose. By selecting the correct type of glucose syrup, glucose-fructose syrup or dextrose it is possible to influence the melting behavior of ice-cream. Also the keeping qualities or the direct consumption out of the freezer can be “designed” by the choice of saccharide composition.
Viscosity is a measure of the internal friction resistance that must be overcome to make a liquid flow. Viscosity, while strongly influenced by dry substance content and temperature, is intrinsically determined by composition. The glucose viscosity is measured in “milli Pascal seconds” (mPa.s) or centipoises (cp), 10.000 mPa.s is considered to be a high viscosity and 180 mPa.s a low viscosity for a glucose-fructose syrup at 40 ºC.