Title: Alternative Sweeteners

16 von Rymon Lipinski and Hanger
III. PROPERTIES
Acesulfame K is a white, crystalline powder. The crystals are monoclinic, of the
P 21/c order. X-ray diffraction demonstrated that the ring system is almost plane,
whereas the distances between the single atoms are less than those calculated
from the theoretical values. The specific gravity of acesulfame K is 1.83 g/cm 3
(6).
The shelf-life of pure solid acesulfame K seems to be almost unlimited at
room temperature. Samples kept at room temperature for more than 6 years and
either exposed to light or protected from it did not show any signs of decomposition
or differences in analytical data compared with freshly produced material
(4).
Acesulfame K does not show a definitive melting point. When the product
is heated under conditions used for melting point conditions, decomposition is
normally observed at temperatures well above 200°C. The decomposition limit
seems to depend on the heating rate. No decomposition of acesulfame K has
been observed under conditions of temperature exposure normally found for food
additives. In contrast to acesulfame K, acesulfame acid has a sharp and definitive
melting point at 123°C (2).
Even at room temperature, acesulfame K dissolves readily in water. The
solubility at 20°C is about 270 g/l water. With rising temperatures, the solubility
increases sharply to more than 1000 g/l at 100°C. In alcohols, however, acesulfame
K is much less soluble. At 20°C, only about 1 g/l dissolves in anhydrous
ethanol. In mixtures of alcohol and water, the solubility increases with rising
water content. In 50% ethanol (v/v), about 100 g/l can be dissolved (2). Aqueous
solutions of acesulfame K are almost neutral (See Table 1).
In view of the temperature/solubility ratio of acesulfame K solutions in
water, the product can be easily purified by recrystallization. High-purity acesulfame
K can thus be produced on a technical scale while meeting the purity requirements
for food additives.
A. Sensory Properties
Acesulfame K exhibits about 200 times the sweetness of a 3% sucrose solution,
although sometimes slightly higher values have been reported (7). The sweetness
intensity depends on the concentrations of the sucrose solution to which it is
compared. At the threshold level, the intensity is much greater and decreases
with increasing sucrose concentrations to values from 130 to 100 times the sucrose
value (Fig. 4). Normally, acesulfame K can be considered to be about half
as sweet as sodium saccharin, similarly sweet as aspartame, and four to five
times sweeter than sodium cyclamate. In acid foods and beverages with the same