Impact of high-pressure homogenization pretreatment on recovery of curcumin from turmeric by different combinations of extraction and drying methods

This study reports the effect of different extraction and drying techniques in the recovery of curcumin, where the impact of the pre-treatment step on turmeric rhizome using high-pressure homogenization (HPH) was evaluated. Soxhlet extraction (SE) and ultrasound-assisted extraction (UAE) followed by drying (oven drying, vacuum drying, and freeze drying) were applied to HPH-treated and control (non-HPH) samples. The HPH treatment condition of 100 MPa for 10 cycles demonstrated the lowest particle sizes in the turmeric suspensions and the highest curcumin content in the aqueous supernatant. It was also found that HPH treatment increased the release of curcumin from the freeze-dried turmeric extracts obtained from SE (+76.2%) and UAE (+57.5%). Besides, freeze drying was the best drying method demonstrating higher antioxidant activity of extracts than other thermal drying methods. The total phenolic content was increased by about 65.5% upon HPH treatment on turmeric extract obtained from UAE followed by vacuum drying.