Bioavailability, Stability and Antioxidant Activity of Ginger and Curcumin Before and After Encapsulation

Ginger (Zingiber officinale) and Curcumin (Curcuma longa L) have been used in folk medicine due to their high content of bioactive components. The stability of these bioactive components is one of the important limiting factors for their utilization. In this study, encapsulation of the bioactive components of ginger and curcumin extracts with maltodextrin or βcyclodextrin by Freeze-dryer was applied to improve the stability and properties of these components. Solubility of C-MD and G-MD was increased to 83.68% and 95.97% respectively, compared with curcumin extract and ginger extract 17.96 % and 28.14%, respectively. The results showed enhancement of total phenol content in G-CD 49.81 mg /100 g DM, while in ginger extract was 43.61mg /100 g DM. The bioavailability of encapsulated plant extracts improved by calculating the retained activity % of reducing power: which was 110.2%, 111.8 %and 121.5% for G-CD, G-MD, and CMD respectively. The stability of the encapsulated plant extracts was studied by measuring the thermal stability and change in pH. The encapsulation of ginger extract with both CD and MD increased the stability of ginger in acidic pH5 and curcumin stability against neutral and alkaline pH. The results showed an increase in the thermal stability of encapsulated plant extracts compared to the studied plant extracts. In G-CD, the total phenols reduced from 49.8mg/ 100 g DM to 32.8mg /100 g DM, after invitro gastric digestion. Encapsulation of ginger and curcumin extracts led to an improvement in solubility, thermal stability, pH stability and bioavailability of bioactive components.