Crystallization of Caffeine by Supercritical Antisolvent (SAS) Process: Analysis of Process Parameters and Control of Polymorphism

Abstract

The recrystallization of caffeine extracted with dichloromethane from coffee beans by a supercritical antisolvent (SAS) process was studied. Acicular crystalline particles with a particle size down to 2.5 μm were obtained, and product purity was increased as a result of SAS processing. Furthermore, by modification of process conditions, it was possible to vary the proportion between the metastable and stable crystalline polymorphic forms of caffeine, obtaining fractions of stable form ranging from 40% to nearly 100%.