This study was conducted to determine the optimal hydrothermal pretreatment
conditions for manufacturing processed ginger products. Ginger slices heated at
different temperatures (60-100°C for 1 h) for varying durations (1-5 h at
80°C) were compared in terms of their physiochemical properties,
antioxidant activities, and functional compound contents. The pH and soluble
solid content decreased with increasing hydrothermal treatment temperature.
Browning occurred at temperatures > 80°C. The
2,2-diphenyl-1-picrahydrazyl and
2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging were
highest after heating at 80°C for 1 h, and the total phenolic compound
content showed a similar trend. As the hydrothermal treatment temperature and
duration increased, the 6-gingerol content decreased and the 6-shogaol content
generally increased. Based on sensory testing of ginger jeonggwa (with sugar
syrup) prepared using hot water-treated ginger slices, the optimal hot water
treatments were conducted at 70 and 80°C for 1 h, with no significant
difference between these temperatures in terms of smell, taste, and texture.
Therefore, hydrothermal treatment of ginger at 70-80°C for 1 h was a
suitable to improve the functionality and antioxidant ability while maintaining
the sensory quality. Therefore, this may be used in the production of processed
ginger.