Aroma
Used in flavor compositions where lower
volatility and improved stability towards air
(oxygen) is desirable, and Benzaldehyde as
such seems too volatile and unstable.
Benzaldehyde glycrol acetal will liberate Benzaldehyde under
influence of heat, water or mild acid, conditions which frequently exist in functional products containing artificial flavor.
Benzaldehyde glycrol acetal itself has a very faint odor, barely
reminiscent of Bitter Almond. Soluble in
alcohol and oils.
Used in fruit flavors, imitation Almond,
Cherry, Nut, etc. in concentrations equal to
100 ppm in the finished consumer product.
Chewing gum may contain up to 800 ppm
of the acetal. Chewing gum is the most common outlet for this acetal.
Preparation
The α, α?- and α, β-isomers are obtained in mixture by heating glycerol and benzaldehyde to 145 to 170°C under a stream
of CO2; the isomers are subsequently isolated, exploiting the solubility differences; the α, α?-isomer is readily converted to the α,
β-form by heating in the presence of HCl.
Production Methods
Benzaldehyde glycrol acetal can be produced from Benzaldehyde and Glycerin by
condensation, using Phosphoric acid as a
catalyst, and making use of azeotropic distillation to remove reaction water.
Also by heating Glycerol and Benzaldehyde
in CO2 atmosphere to 150°C. The 1,3-isomer
is crystallizable and may be separated.
