Color improvement by irradiation of Curcuma aromatica extract for industrial application

Curcuma species are medicinal herbs with various pharmacological activities. They have a characteristic yellow color and contain curcuminoids which are natural antioxidants. In this study, Curcuma aromatica (CA) and Curcuma longa (CL) extracts were gamma-irradiated for improving the color, and the irradiation effects on the curcuminoids contents in CA and CL extracts were determined in order to evaluate if CA can replace CL on the market, where the price of CA is 70% lower than the price of CL. The Hunter color L*-values were increased significantly in all the samples with increasing dose, while the a*-values and b*-values decreased, which implies that the color of the CA and CL extracts changed from dark yellow to brighter yellow. Curcuminoids contents of all the samples were evaluated, and CA contains more curcuminoids than CL. These results indicated that irradiation improved the properties of CA for possible industrial use in manufacturing food and cosmetic industrial products.