Conversion of 6 gingerol to 6 shogaol in ginger (Zingiber officinale) pulp and peel during subcritical water extraction.
Subcritical water extraction is an eco friendly method for the extraction of less polar compounds without the use of organic solvents. This study determined the extraction conditions that maximize the contents of 6 gingerol and 6 shogaol obtained from ginger pulp and peel. The highest yields of 6 gingerol (0.68 0.08 mg/g) and 6 shogaol (0.39 0.03 mg/g) were obtained from ginger pulp at the extraction conditions of 130 degC/25 min, and 190 degC/15 min. 6 Shogaol content increased with the increasing extraction temperature and extraction time due to the conversion of 6 gingerol to 6 shogaol by thermal cracking. The antioxidant activity of ginger extracts were increased depending on the increasing of 6 shogaol content.
Food chemistry