Precipitation of curcuminoids from an ethanolic turmeric extract using a supercritical antisolvent process

Abstract

This study examined the precipitation of curcuminoids from an ethanolic extract using a supercritical antisolvent process (SAS). The ethanolic extract was obtained from deflavored turmeric using pressurized liquid extraction (PLE). A Split-Plot experimental design was used to evaluate the effects of process parameters, such as nozzle type (T-mixer and coaxial), temperature (313 and 333K), pressure (10 and 12MPa) and CO2 flow (500 and 800g/h), on the curcuminoids precipitation process. The results indicate that the T-mixer nozzle obtained a higher yield and a lower particle size than the coaxial nozzle. Particles of curcuminoids were precipitated with a global yield of solids of 69% and a curcuminoid content of 554mg/g. This corresponds to a precipitation efficiency of 97%. The particles precipitated via SAS contained a curcuminoid content 2 and 31 times higher than the extracts obtained by rotary evaporation and the ethanolic extract, respectively, obtained by PLE. Depending on experimental conditions, the particles were characterized as polydispersed and agglomerated into larger structures (by up to 100μm) with different morphologies.