Various Extraction Techniques of Curcumin-A Comprehensive Review

Curcumin, the active component of the rhizome of Curcuma longa, is a safe substance whose applications are extensively used in medicinal, biological, pharmacological activities, and food cosmetic additives. In the field of medicine, curcuminoids have a greater impact; they have been associated with the suppression of neuropathic pain, depression, angiogenesis, tumorigenesis, diabetes, and diseases of the liver, skin, and pulmonary systems, as well as cardiovascular and nervous systems. These are in high demand and have high market potential and inflated costs. For the aforementioned uses, as well as for basic research, it is crucial to get pure curcumin from plant sources. There is a need for effective extraction and purification techniques that adhere to standards for process efficiency, environmental friendliness, and safety. Scope: This account offers an accurate and thorough explanation of the many techniques used to extract and purify curcumin from plant sources, as well as a look at its various roles in the pharmaceutical, cosmetic, medical, and other industries. Curcumin's prospective and commercial roles are also discussed. Key findings: Curcuminoids have been extracted and purified by using a broad range of techniques that are utilized extensively across the world. Extraction of curcuminoids includes both traditional and contemporary approaches, of which a handful include Soxhlet extraction, maceration, solvent extraction, ultrasound-assisted extraction, microwave-assisted extraction, enzyme-assisted extraction, and supercritical liquid extraction. The other process called purification can be performed alone or in combination with techniques. The use of column chromatography and semipreparative high-performance liquid chromatography are examples of traditional purification procedures, and other innovative methods include high-speed counter-current chromatography and supercritical fluid chromatography.

Optimization of ethanol-modified subcritical water extraction of curcuminoids from turmeric (Curcuma longa L.) rhizomes: Comparison with conventional techniques

Subcritical solvent extraction (SSE) as ethanol-modified subcritical water extraction (SWE) was applied to extract curcuminoids from turmeric (Curcuma longa L.) rhizomes. RSM-CCD was employed to evaluate the influential factors including temperature (90-150 °C), flow rate (1-4 mL/min), and ethanol concentration (25-75 wt%) on the extraction yield. The optimum condition was 90 °C, 4 mL/min, and 25 wt% with the extraction yield of 4.12 wt% (db). Applying ethanol as a polarity-tuning parameter enabled operations at lower temperatures, which prevented thermal degradation. The SSE optimum experiment was compared with Soxhlet, ultrasound-assisted extraction (UAE) and conventional solvent extraction (CSE), both with the ethanol-water mixture (25 wt%). Their yields were 2.71, 0.85, and 0.84 wt% (db), respectively. The higher yield of SSE was related to the higher solubility of curcuminoids due to the more appropriate adjustment of solvent polarity by a decrease in the dielectric constant with a rise in the operating temperature.