Abstract:

The solubility and super-solubility of aspartame in ethanol-aqueous mixture with different ethanol mass fractions
at 5–60 ℃ were determined, and the apparent nucleation order m was calculated. Meanwhile, the nucleation rate equation
was achieved. The surperstaturation curve and metastable region of aspartame were obtained. It was found that the solubility
data could be described well by the model of λh equation; in addition, the influences of temperature, solvent composition,
cooling rate and agitation rate on the width of metastable zone were explored. The results showed that the solubility of
aspartame in the selected solvents increased with an increase in temperature and ethanol mass fraction, and a synergistic
effect on solubility was observed at w = 0.5 (m/m). Contrary to the solubility, the width of metastable zone decreased with
increasing temperature and ethanol mass fraction; under the same experimental conditions, either decreasing agitation rate or
increasing cooling rate may broaden the width of metastable zone.

Key words: aspartame, solid-liquid equilibrium, solubility, λh model, metastable zone