Stability of Phytochemicals and Antioxidant Properties in Ginger ( Zingiber officinale Roscoe) Rhizome with Different Drying Methods.

Effects of drying methods on the stability of phytochemicals and antioxidant properties of ginger (Zingiber officinale) were assessed. The rhizomes were collected at 9 and 12 months after planting and sun-dried, freeze-dried, or oven-dried at 40°, 50°, 60°, or 70° C. Oven drying at 60° C resulted in significant gains of phenolics (441.85 mg.100g−1 d.w), antioxidant activities (78.45 ± 2.04% and 650.45 ± 50.04 μmol Fe (II).g−1 dry extract) of ginger rhizomes at 9 months after planting. Oven drying at 70° C resulted in significant gains of phenolics (450.02 mg.100g−1 dry weight), antioxidant activities (79.34 ± 1.20% and 662.31 ± 17.01 μmol Fe (II).g−1dry extract) of ginger rhizomes at 12 months after planting. [ABSTRACT FROM PUBLISHER]