Food Chemistry

8.8 Sweeteners 441

pounds with active methylene groups, as exempli-
fied by 1,3-diketones, 3-oxocarboxylic acids and
3-oxocarboxylic acid esters:

(8.16)

The sweetness of acesulfame is perceived quickly
and this substance is practically stable in foods
under the common processing and storage con-
ditions. It is used in a large number of different
products.

8.8.15 Dipeptide Esters and Amides

8.8.15.1 Aspartame

A dipeptide,L-aspartyl-L-phenylalanine methyl
ester (L-Asp-L-Phe-OMe), has recently been

Table 8.10.Comparison of sweetening strengths of

aspartame and saccharose (concentrations of isosweet

aqueous solutions in %)

Saccharose Aspartame fsac, g

0. 34 a 0. 001 a 340

4. 30. 02 215

10. 00. 075 133

15. 00. 15 100

aThreshold value.

approved for use as a sweetener in North

America (aspartame, “NutraSweet”). It is as

sweet as a number of other dipeptide esters of

L-aspartic acid andD,L-aminomalonic acid. The

relationship between chemical structure and

taste among these compounds was outlined in

more detail in 1.3.3. The sweetening strength

relative to saccharose is concentration dependent

(Table 8.10). Aspartame is used worldwide,

though its stability is not always satisfactory.

Unlike sweetening of drinks (coffee or tea) which

are drunk immediately, problems arise in the

use of aspartame in food which has to be heated

or in sweetened drinks which have to be stored

for longer periods of time. Possible degradation

reactions involveα/β-rearrangement, hydrolysis

Table 8.11.Taste of some dipeptide amides of the type

L-Asp-D-Ala-NHR

R fsac, g( 10 )

Cyclopentyl 50

Cyclohexyl 90

(2,2,5,5-tetramethyl)-cyclopentyl 800

(2,2,6,6-tetramethyl)-cyclohexyl 300

(Diethyl)-methyl 100

(Diisopropyl)-methyl 250

(Di-tert-butyl)-methyl 450

(Di-cyclopropyl)-methyl 1200

(Cyclopropyl)-(tert-butyl)-methyl 1200

(Cyclopropyl)-(methyl)-methyl 100

(2,2,4,4-Tetramethyl)-cyclobutyl 300

(2,2,4,4-Tetramethyl)-cyclobutan-3-onyl 240

(3-Hydroxy-2-2,2,4,4-tetramethyl)-cyclobutyl 125

3-(2,2,4,4-Tetramethyl)-thietanyl 2000 a

3-(1-cis-Oxo-2,2,4,4-tetramethyl)-thietanyl 300

3-(1-trans-Oxo-2,2,4,4-tetramethyl)-thietanyl 350

3-(1,1-Dioxo-2,2,4,4-tetramethyl)-thietanyl 805

aAlitame.