Curcumin extracts from Curcuma Longa - Improvement of concentration, purity, and stability in food-approved and water-soluble surfactant-free microemulsions

Curcumin was extracted from Curcuma Longa employing a green, bio-based, and food-agreed surfactant-free microemulsion (SFME) consisting of water, ethanol, and triacetin. Concerning the high solubility of curcumin in the examined ternary mixtures, it was attempted to produce highly concentrated tinctures of up to a total of similar to 130 mg/mL curcuminoids in the solvent by repeatedly extracting fresh rhizomes in the same extraction mixture. The amount of water had a significant influence on the number of cycles that could be performed as well as on the extraction of the different curcuminoids. In addition, the purity of single extracts was enhanced to 94% by investigating several purification steps, e.g. vacuum distillation and lyophilization. Through purification before extraction, the water insoluble curcumin extract could be solubilized indefinitely in an aqueous environment. Additional stability tests showed that solutions of curcumin can be stable up to five months when concealed from natural light.

Automated summary

Curcumin was extracted from Curcuma Longa using a surfactant-free microemulsion, producing highly concentrated tinctures of up to 130 mg/mL curcuminoids. Water content influenced the extraction process and the purity of the extracts, with additional purification steps enhancing purity to 94%. Purification before extraction allowed for indefinite solubilization of water insoluble curcumin extracts in aqueous environments, with stability of the solutions for up to five months when kept away from natural light.