• The Korean Journal of Food And Nutrition
• /
• v.31 no.4
• /
• pp.559-564
• /
• 2018

Rehmannia glutinosa root (R. root) has been used as an traditional medicine, and is important resource for natural medicines and functional foods. However, R. root contains catalpol which is bitter, and undigested sugars, including stachyose and raffinose, which can cause diarrhea. Therefore, this study was performed to identify the changes in reducing sugar from undigested sugars and in catalpol contents in R. root slurry induced by aging treatments. R. root slurry was treated at $10{\sim}70^{\circ}C$ for up to 72 hr; and extracted with a 50% ethanol solution. The catalpol content was analyzed using HPLC-UVD. Reducing sugar content generated from undigested sugars was measured by the Nelson-Somogyi methods, and the reaction rates were calculated from their variation according to aging time and temperature. During the aging treatment, reducing sugar increased and catalpol decreased. Their formation and degradation rates were highest at $50^{\circ}C$ and $30{\sim}40^{\circ}C$, and their rates were $2.05mg/g{\cdot}hr$ and 23.09 to 23.33%/hr, respectively. These results indicated that aging treatment can positively affect the sweetness and digestibility of R. root slurry. Therefore, an aging treatment could be considered for improving the taste and digestibility of R. root.