Views: 80 Author: Site Editor Publish Time: 2026-07-08 Origin: Site
How to extract curcumin from turmeric using ultrasonic equipment?
Turmeric (Curcuma longa L.) is an important medicinal and edible crop in the Zingiberaceae family. The curcumin contained in its rhizome has multiple pharmacological activities such as antioxidant, anti-inflammatory, antibacterial, anti-tumor and neuroprotection. However, curcumin has poor water solubility, unstable chemical properties, and is easily decomposed, resulting in difficulty in extraction and low extraction yield. Traditional extraction methods (such as thermal reflux and impregnation methods) rely on concentration gradient diffusion and have problems such as low efficiency, high energy consumption, and large solvent consumption. The emergence of ultrasonic-assisted extraction technology provides a new solution for efficient and green extraction of curcumin.
Ultrasound is a mechanical wave with a frequency higher than 20kHz. Ultrasound-assisted extraction technology applies the comprehensive effects of cavitation, vibration, crushing, and stirring generated by ultrasonic waves to the extraction process of natural product components, and achieves the process of extracting cell contents by destroying cell walls. Its core mechanism mainly includes three aspects:
(1) Cavitation effect. This is the most important mechanism of action of ultrasonic extraction. When high-energy ultrasonic waves act on a liquid medium, the medium is torn into many tiny cavities. These cavities rapidly expand and close under the action of the sound field, instantly generating instantaneous pressures and local high temperatures of up to thousands of atmospheres. Research shows that the collapse of cavitation bubbles can produce an instantaneous high temperature of about 5000K and a local high pressure of 1000atm. This strong shock wave can cause the plant cell wall and the entire organism to rupture in an instant, allowing the curcumin components in the cytoplasm to quickly dissolve into the surrounding solvent.
(2) Mechanical effect. When ultrasonic waves propagate in the medium, they produce periodic pressure changes and form microfluidic shear forces, which can directly break cell walls. At the same time, the vibration generated by ultrasound enhances the release, diffusion and dissolution of intracellular substances.
(3) Thermal effect. Sound energy is converted into thermal energy through medium friction, which can increase the extraction temperature to a certain extent, promote the thermal movement of molecules, and increase the diffusion coefficient by 2 to 3 orders of magnitude. Compared with traditional heating methods, ultrasonic extraction has better temperature controllability and is especially suitable for the extraction of heat-sensitive components.
Technical Advantages
Compared to traditional extraction methods, ultrasound-assisted extraction of curcumin offers the following significant advantages:
High extraction efficiency. The unique physical properties of ultrasound can disrupt or deform plant cell walls, resulting in more complete extraction of active ingredients. The extraction rate is significantly increased by 50% to 500% compared to traditional processes. Studies have shown that ultrasound-assisted extraction of curcumin achieves a single-pass extraction rate of 79.7%, far exceeding the 62.6% of traditional solvent reflux extraction. Another study achieved a curcumin extraction rate of 3.56% under optimized conditions.
Short extraction time. Ultrasonic-enhanced extraction typically achieves the optimal extraction rate within 24 to 40 minutes, reducing the extraction time by more than two-thirds compared to traditional methods. Extraction processes requiring hours or even longer using traditional methods are shortened to minutes with ultrasound assistance.
Low extraction temperature. The optimal temperature for ultrasonic extraction of medicinal herbs is between 40 and 60°C, which protects the heat-labile, easily hydrolyzed, or oxidized active ingredients while significantly reducing energy consumption.
Green and environmentally friendly. Ultrasonic-assisted extraction technology boasts advantages such as accelerated extraction efficiency, energy conservation, and environmental friendliness, thus being considered a "green technology." Studies show that ultrasonic extraction can reduce solvent consumption by more than 50%.
It has wide applicability. Ultrasonic extraction is not limited by the polarity or molecular weight of components, making it suitable for the extraction of most types of Chinese medicinal herbs and various components.
Ultrasonic extraction of curcumin is a well-developed technology with many different process routes to choose from. Its core principle is the same as that of turmeric oil extraction: utilizing the "cavitation effect" of ultrasound to disrupt plant cell walls, allowing the active ingredients to be released more quickly.
Extraction Method Selection: Depending on the research, various processes are available for reference. You can choose or combine them based on your own conditions (such as equipment, raw materials, and objectives).
Detailed Operating Procedure
A typical extraction process usually includes the following steps:
Raw Material Preparation: Wash turmeric, dry it at a low temperature (e.g., 50℃), then pulverize it and sieve to obtain a uniform powder. The degree of dryness and powder fineness of the raw material affect the extraction efficiency.
Solvent Preparation: Prepare an ethanol solution of appropriate concentration according to the selected process. 60%-75% ethanol is the most commonly used extraction solvent in the literature.
Mixing and Ultrasonic Extraction: Mix the turmeric powder with the ethanol solution at a material-to-liquid ratio (e.g., 1:15 or 1:60).
Place the mixture in an ultrasonic device, set the power, temperature, frequency, and time parameters, and start the extraction.
Light Protection: Curcumin is easily decomposed by light; the extraction process should be carried out in a light-protected environment.
Solid-Liquid Separation: After extraction, separate the curcumin-containing extract from the solid residue by filtration or centrifugation.
Solvent Recovery and Product Drying: Use equipment such as a rotary evaporator to recover ethanol under reduced pressure to obtain a concentrated crude curcumin extract, which is then dried. Product purification (optional): For higher purity curcumin, the crude extract can be further purified, for example, using macroporous adsorption resin for adsorption and desorption.
Ultrasonic-assisted extraction technology has become a mature, efficient, and environmentally friendly core technology for extracting curcumin from turmeric. Its value lies in the synergistic effect of the cavitation, mechanical, and thermal effects of ultrasound, which efficiently breaks down plant cell walls, significantly improving extraction efficiency, shortening extraction time, and reducing energy and solvent consumption.
In the future, with the continuous optimization of ultrasonic equipment design, the deep integration of ultrasound with green media such as eutectic solvents, and the widespread application of innovative technologies such as microwave-ultrasonic combined extraction, ultrasonic extraction technology for curcumin is expected to play a greater role in the food, health product, and pharmaceutical industries. Simultaneously, the widespread application of statistical optimization tools such as response surface methodology will make precise control of process parameters more convenient, providing solid technical support for the efficient, environmentally friendly, and industrialized extraction of curcumin.
