2018 Volume 24 Issue 4 Pages 687-696
Using HPLC, it was demonstrated that the major free phenolic compound in the pericarp and seed coat of red rice was cyanidin, which belong to anthocyanidin glucoside, exist only in the episperm of red rice as content of 1.64±0.10 mg/g. Anthocyanidin glucoside play a significant role in eliminating free radicals and reacting oxygen species (ROS) to prevent cellular oxidative stress. However, the chemical stability of anthocyanidin glucoside has been one of the major drawbacks for health applications. For longer storage, our results showed that red rice anthocyanidin glucoside could be stored with 0.3 % Vitamin C or 0.5 % NaHSO3, and be protected from light, high temperature, high pH and metal ions in environment. Antioxidant activity verified that anthocyanidin glucoside performed better than Vitamin C in ferrous ions chelating activity, scavenging activities for hydroxyl and DPPH radicals. Overall, the red rice might be used as a natural antioxidant supplement applying medical treatments in future days.