Extraction of curcuminoids by using ethyl lactate and its optimisation by response surface methodology

Area of Science:

• Natural Product Chemistry
• Green Chemistry
• Analytical Chemistry

Background:

• Curcuminoids, the active compounds in turmeric, possess valuable therapeutic properties.
• Efficient extraction and stabilization of curcuminoids are crucial for their application in pharmaceuticals and food.
• Traditional extraction methods may involve harsh conditions or less sustainable solvents.

Purpose of the Study:

• To optimize the extraction of curcuminoids from turmeric using a mixture of ethyl lactate (EL), ethanol, and water.
• To investigate the stability of curcuminoids in different solvent mixtures and pH conditions.
• To evaluate ethyl lactate as a potential solvent for curcuminoid extraction and formulation.

Main Methods:

• Response Surface Methodology (RSM) with an augmented simplex-centroid mixture design.
• High-Performance Liquid Chromatography (HPLC) for quantifying curcuminoids.
• Stability studies assessing degradation kinetics at varying pH and solvent compositions.

Main Results:

• A water-EL mixture (30:70 v/v) achieved near-quantitative recovery of curcuminoids.
• Curcuminoids exhibited significantly greater stability in ethyl lactate compared to water, especially under alkaline conditions.
• The water-EL mixture inhibited alkaline hydrolysis, extending curcuminoid half-lives.

Conclusions:

• Ethyl lactate is a highly effective and stabilizing solvent for curcuminoid extraction from turmeric.
• The optimized water-EL solvent system offers a mild and efficient method for obtaining curcuminoids.
• Ethyl lactate shows potential as a suitable medium for formulating curcuminoids into drugs and food products.