Evaluation of high-pressure homogenization as a pretreatment for the extraction and drying of 6-gingerol from ginger

6-Gingerol is the major biologically active component found in the ginger rhizome, and this study investigated the effect of high-pressure homogenization pretreatment on the recovery of 6-gingerol. The smallest particle size of ginger suspension was achieved using high-pressure homogenization treatment at 100 MPa for 10 cycles. The total phenolic content (TPC) and antioxidant activity of ginger supernatants were enhanced at higher intensity of high-pressure homogenization pretreatment. At 50 MPa and 100 MPa of 1 cycle of high-pressure homogenization, the recovery of 6-gingerol content was increased by 112.9% and 79.1%, respectively. The high-pressure homogenization-treated and control ginger extracts obtained from ultrasound-assisted extraction and Soxhlet extraction were dried by various methods. All pretreated high-pressure homogenization samples showed a significantly higher 6-gingerol content than control samples. Using Soxhlet and ultrasound-assisted extractions, pretreated freeze-dried high-pressure homogenization ginger extracts demonstrated the highest antioxidant activity. In contrast, pretreated oven-dried high-pressure homogenization ginger extracts exhibited the highest TPC. This study demonstrated that high-pressure homogenization is a potential pretreatment method combined with various extraction and drying techniques for the efficient recovery of 6-gingerol from the rhizome of ginger.