Dipeptide sweetener sulfate and sulfonate salts

DETAILED DESCRIPTION OF THE INVENTION Dipeptide sweetener sulfate and organosulfonate salts of formulas I and II show substantial thermal stability and dissolve quickly in aqueous media.
In addition, the factors generating enhanced thermal stability also lengthen the effective shelf life of the salts.
The low thermal stability shown by known acid dipeptide sweetener salts such as the hydrochloride and the bisulfate correlates with the low thermal stability of the free base forms of the dipeptide sweeteners.
It follows that acid dipeptide sweetener salts generally would not be expected to have substantially high thermal stability.
It is surprising, therefore, that the dipeptide sweetener sulfate and sulfonate salts of the invention, which are acid salts, exhibit thermal stabilities which permit their effective use at minimum sweetening level amounts and under cooking, heating or baking conditions.
Furthermore, it is surprising to find that the salts of the invention exhibit a very fast rate of dissolution in cold, aqueous media.
Consequently, the salts of the invention can be almost universally substituted in place of sugar.
They can be used in both hot and cold food and beverage applications whereas the free base and known salt forms of dipeptide sweeteners can not.
To prepare the salts of the invention, a dipeptide sweetener is mixed with a minimum amount of a highly polar solvent containing the appropriate acid for salt formation so that the weight ratio of sweetener to polar solvent is from about 30 percent to 50 percent.
The amount of acid, i.
e.
sulfuric acid or sulfonic acid (RSO.
sub.
3 H), typically employed will be about an equivalent, i.
e.
, one-half and one molar amounts respectively.
During this step, the mixture may remain at ambient temperature or may be gently warmed to a temperature of about 40.
degree.
to 60.
degree.
, preferably 50.
degree.
.
If the mixture is warmed, salt formation will tend to proceed from a homogeneous solution, (while at lower temperatures, the mixture may remain cloudy and heterogeneous