COMPLEXATION OF CURCUMIN USING WHEY PROTEINS TO ENHANCE AQUEOUS SOLUBILITY, STABILITY AND ANTIOXIDANT PROPERTY

Abstract

The stability and solubility of curcumin, CCM, can be enhanced by complexation with whey protein concentrate (WPC). The CCM-WPC of 1:1 and 1:0.5 molar ratio complexes were encapsulated by two methods, namely spray drying (SD) and freeze drying (FD). The major objective of this work is to determine the stability and solubility of the CCM-WPC complexes encapsulated by SD and FD method. The X-ray diffraction and thermogravimetric analysis were performed on raw CCM and WPC, and on their complexes. The changes in thermal degradation and in crystallinity suggest the formation of these CCM-WPC complexes. Scanning electron microscopy images showed that the used methods influenced the morphology and the properties of the formed complexes. The stability and solubility of curcumin are enhanced by complexation in both encapsulation methods. However, comparing the used molar ratio and drying methods, the results are various. The solubility of samples obtained by FD method was higher than in the case of the SD method, which can explain the difference of their morphology (FD samples are more amorphous than SD samples). The antioxidant property of curcumin and its protein-complexes compared to vitamin C showed that CCM and its complexes have a lower IC₅₀ value than vitamin C, i.e., the antioxidant effect of CCM is higher. The addition of WPC improved the antioxidant activity of CCM, probably due to its encapsulation in the protein. Our results suggest that the 1CCM-1WPC_SD complex is the best antioxidant from these studied CCM-WPC complexes.