Diversity of curcuminoids, bioactive compounds and antioxidant activities in three species of Curcuma

Purpose: To investigate the physical characteristics, bioactive compounds and antioxidant activities of curcuminoids, phenolic acids, and flavonoid compounds in three Curcuma species (C. mangga, C. zedoria, and C. longa). Methods: Rhizomes of three Curcuma species (C. mangga, C. zedoria, and C. longa) were collected, and then curcuminoids, phenolics and flavonoid acids were determined using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy. Antioxidant activities were assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results: Variations in colour metrics such as lightness (L*), red-green (a*), and yellow-blue (b*) indicated different bioactive compounds. C. longa exhibited significantly higher concentration of curcuminoids (333.2 µg/g DW), total phenolic content (TPC, 116.7 mg GAE/g DW) and total flavonoid content (TFC, 16.1 mg RE/g DW) compared to C. mangga, and C. zedoria (p < 0.05). Furthermore, C. longa exhibited significantly higher antioxidant activity than C. mangga, and C. zedoria (p < 0.05). Conclusion: The results indicate significant variations in bioactive composition between the three species of the genus Curcuma. Curcuma longa shows significantly higher concentration of curcuminoids, TPC, and TFC as well as antioxidant activity compared to C. mangga and C. zedoria. Future studies are required to examine the impact of natural variables, growing conditions, and processing techniques on the prevalence of bioactive chemicals and correlation with biological activities.