Thai Curcuma Species: Antioxidant and Bioactive Compounds

For the functional food applications, antioxidant properties and the bioactive compounds of the 23 Curcumaspecies commercially cultivated in Thailand were studied. Total phenolic content and DPPH radical scavenging activity were determined. The concentrations of eight bioactive compounds, including curcumin (1), demethoxycurcumin (2), bisdemethoxycurcumin (3), 1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (4), germacrone (5), furanodienone (6), zederone (7), andar-turmerone (8), were determined from theCurcumaby HPLC. While the total phenolic content ofC. longawas highest (22.3 +/- 2.4 mg GAE/g, mg of gallic acid equivalents),C.Wan Na-Natong exhibited the highest DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) radical scavenging activity. Twenty-three Curcuma species showed characteristic distributions of the bioactive compounds, which can be utilized for the identification and authentication of the cultivatedCurcumaspecies.C. longacontained the highest content of curcumin (1) (304.9 +/- 0.1 mg/g) and C. angustifoliacontained the highest content of germacrone (5) (373.9 +/- 1.1 mg/g). It was noteworthy that 1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (4) was found only from C. comosaat a very high concentration (300.7 +/- 1.4 mg/g). It was concluded that ThaiCurcumaspecies have a great potential for the application of functional foods and ingredients.