Tailoring Properties of Acidic Types of Natural Deep Eutectics Solvents (NADES): Enhanced Solubility of Curcuminoids from Curcuma zeodaria

Department of Chemical Engineering, Faculty of Technology Industry, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia

^* Corresponding author: orchidea@chem-eng.its.ac.id

Abstract

Recently Natural Deep Eutectic Solvents (NADES) show their potential as a promising green solvents at 21^th century for extraction of natural products. Rutin, a poorly water soluble flavonoid, was reported better solubilized in NADES than in water as well as a paclitaxel and ginkgolide B, a completely water-insoluble compound. In case of curcuminoids, phenolic compounds from powder of Curcuma Zeodaria shown better solubilized in acidic type of NADES such malic acid-sucrose-water (MAS-H₂O = 1:1:11, mole ratio) and citric acid-sucrose-water (CAS-H₂O = 1:2:15, mole ratio) compare to water and ethanol. Indicating that NADES, a water-based solvent, appropriate for extracting curcuminoids. However, the inherent high viscosity of NADES hamper the process extraction. Lowering the viscosity, water content of NADES is varied, adding a certain amount of water up to 60% of water content. All the varied water content of both CAS-H₂O and MAS-H₂O were successfully extracted curcuminoids. Yielded 0.06-0.16 mg curcuminoids/g dry weight. However, 60% of water content of both CAS-H₂O and MAS-H₂O gave more or less similar value of curcuminoids to CAS-H₂O (20% of water) and MAS-H₂O (30% of water). Curcuminoids is more stable in CAS-H₂O compare to MAS-H₂O for 96 h of time duration.