Preparation of curcumin sub-micrometer dispersions by high-pressure homogenization.

High-pressure homogenization (HPH) processing has been used to increase the water dispersity of curcumin, a popular spice and coloring and antioxidant agent, which shows anti-inflammatory and anti-cancer properties but poor water solubility and oral bioavailability. The optimized HPH treatment was achieved at the combined conditions of temperature at 2 degrees C, pressure at 150 MPa, and 10 HPH cycles. The mechanism behind the improved water dispersity of curcumin by HPH treatment was interpreted as a result of the reduced curcumin particle sizes and crystallinity caused by mechanical stresses, which were verified by particle size measurements, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results. Spray drying of maltodextrin (MD)-entrapped curcumin can also increase the water dispersity of curcumin. A combination of HPH treatment and spray drying using MD exhibits a faster curcumin dissolution while retaining a higher water dispersity of curcumin than curcumin prepared by either spray drying using MD alone or the combination of HPH and freeze-drying using MD, suggesting that the combination of HPH processing with spray drying would be an excellent processing method for curcumin-based functional food products.