Separation and nucleation control of α and β polymorphs of l-glutamic acid by swift cooling crystallization process

Separation of crystal nucleation of the two known polymorphs of L: -glutamic acid, the metastable α and the stable β, from pure aqueous solution is attained by following a swift cooling crystallization process. Results elucidate a clear distinction of the preferred nucleation regions of α, β and combinations of α and β in the temperature range between 1 and 40°C. Also, the type of nucleation is supersaturation dependent: higher supersaturation favours α and lower supersaturation favours β. Morphology and structure of the polymorphs confirm their form of crystallization.