2009_Book_FoodChemistry

440 8 Food Additives
and the thiocarbamoyl compound are also sweet.
8.8.13 Oximes
8.8.12.2 Guanidines
(8.11)
It has long been known that the anti-aldoxime
of perillaldehyde (discovered in the essential oil
of Perilla nankinensis) has an intensive sweet
taste ( f sac, g ∼ 2000). For its structure see Formula
8.14 (I).
Derivatives of guanidinoacetic acid (Formula
8.12) are among the sweetest compounds
known until now (Table 8.8).
(8.12)
Replacement of the carboxyl group by a tetrazole
residue results in loss of sweetening strength (Table
8.8).
The guanidines can be synthesized, e. g., via the
isothiocyanates:
(8.13)
(8.14)
In the meantime, a related compound, (II), with
improved solubility, has been reported, but its
sweetness is just moderately high ( f sac, g ∼ 450).
8.8.14 Oxathiazinone Dioxides
These compounds (Formula 8.15) belong to
a class of sweeteners with an AH/B-system
corresponding to that of saccharin. Based on their
properties and present toxicological data, they are
suitable for use. The sweetening strength depends
on substituents R 1 and R 2 and is f ac, g (10)=200
for acesulfame K (Table 8.9).
The ADI value stipulated for the potassium salt of
acesulfame is 0–9 mg/kg of body weight.
Table 8.8. Taste of some guanidines (Formula 8.12)
R R 1 R 2 f sac, g (2)
p-Cyanophenyl H Carboxy- 2700
methyl
Benzyl 30,000
Phenylsulfonyl 45,000
1-Naphthyl 60,000
Cyclohexyl 12,000
Cyclooctyl 170,000
Cyclononyl 200,000
3,5-Dichloro- Benzyl 80,000
phenyl Cyclooctyl 60,000
p-Cyanophenyl Cyclohexyl Tetrazolyl- 400 a
methyl
Cyclooctyl
5000 b
a f sac, g (4).
f sac, g (5).
(8.15)
Oxathiazinone dioxides are obtained from fluorosulfonyl
isocyanate and alkynes, or from com-
Table 8.9. Sweetness of some oxathiazinone dioxides
(Na-salts) (Formula 8.15)
R 1 R 2 f sac, g R 1 R 2 f sac, g
H H 10 Et H 20
H Me 130 a Et Me 250
Me H 20 Pr Me 30
Me Me 130 i-Pr Me 50
H Et 150
a Acesulfame.