Strategies for Higher Yields in Botanical Extraction
In order to produce premium-quality extracts from botanicals with high efficiency, i.e. high yields of premium quality extracts within a short extraction time, a high-performance extraction technique is required. Ultrasonic extraction is a process intensifying technique, which allows to use a wide range of raw materials and produces high yields of superior extracts in a rapid and cost-effective manner.
Premium Botanical Extracts with Power Ultrasound
When an specific bioactive compound or a bioactive fraction from a botanical is extracted, various factors influence the extraction process. Besides the extraction technology (e.g., ultrasonic extraction), the polarity of the solvent, raw material and its pre-treatment, solid / liquid ratio (i.e., plant matter / solvent ratio), extraction time, and temperature are important process factors that must be carefully considered. Ultrasonically assisted extraction (UAE) allows for ideal processing conditions, which are characterized by mildness and high efficiency simultaneously. Free choice of mild solvents or cold-water extraction, low temperatures, and short processing times turn ultrasonic extraction into the superior extraction technique, which prevents thermal or chemical degradation of the bioactive molecules. Furthermore, UAE can release the complete available amount of bioactive molecules from the plant raw material. This is why ultrasonication is the most widely used extraction technology for the production of high-potency extracts.
What makes Ultrasonic Extraction Superior?
Ultrasonically-assisted extraction (UAE) is a highly efficient extraction technique, which is based on pure mechanical forces. Ultrasonic or acoustic cavitation is characterized by intense shear forces as well as locally occurring high temperature and pressure differentials. These highly intense cavitational forces cause so-called sonoporation, which is the generation of new and the enlargement of existing pores in the cell membrane, as well as the disruption of plant cell structures. The ultrasonically intensified flux of solvent in and out of the cell interior contributes to the rapid and complete release of the botanical substances. Using solely mechanical forces, UAE does not alter the botanical molecules via chemicals or intense heat treatment and prevents thereby chemical or heat-induced alterations of the bioactive substances found in botanicals. As result, ultrasonic extraction produces high-quality, full-spectrum extracts which offer the full effects of combined botanical substances, known as so-called entourage effect.
Ultrasonic Extraction: mild non-thermal, yet highly efficient technique for high yields of premium-quality extracts.
Comparison of Ultrasonic Extraction with Other Techniques
Ultrasonic extraction is a widely used technique to release and isolate bioactive compounds such as antioxidants, polyphenols, polysaccharides, proteins, lipids, cannabinoids and other phytochemicals from plant materials.
Sonication is the preferred method due to numerous advantages such as high / complete extraction yields, rapid, non-thermal processing, compatibility with almost any solvents (e.g. water, ethanol, methanol, isopropanol, vegetable oils, glycerine etc.), simple and safe operation, low maintenance amongst many others.
The table below compares ultrasonic extraction with other conventional extraction methods underlining the advantages of UAE.
|Ultrasonic Extraction||Maceration||CO2 Extraction||Soxhlet||Percolation|
|Solvent||compatible with almost any solvent||water, aqueous and non-aqueous solvents||CO2||water, aqueous and non-aqueous solvents||organic solvents|
precise temperature control
|ambient||under heat||ambient temperature,
occasionally heat is applied
|above the critical
temperature of 31°C
|Pressure||both, atmospheric or
elevated pressure possible
|atmospheric||atmospheric||atmospheric||very high pressures
(above the critical pressure of 74 bar)
|Processing Time||rapid||very slow||slow||very slow||moderate|
|Amount of Solvent||low,
high solid load of plant material
in the solvent, especially when a flow cell
setup is used
|large||moderate||large||large amounts of
|Polarity of Natural Extract||dependent on solvent;
to extract non-polar and polar
compounds, a dual-stage extraction
using two solvents is recommended
|dependent on solvent||dependent on solvent||dependent on solvent||dependent on pressure
(under higher pressures more polar)
|Flexibility / Scalability||for batch and inline extraction,
|batch extraction only,
|batch extraction only,
|batch extraction only,
|batch extraction only,
limited linear scalability,
Why is Ultrasonic Extraction so Efficient?
The extraction intensifying mechanism of power ultrasound is mainly attributed to the phenomenon of acoustic cavitation. Ultrasonic cavitation causes collisions between particles of the botanical biomass, which results in interparticular fractioning and reduction of particle size. When cavitation bubbles collapse on the surface of the vegetable solids, erosion and sonoporation enlarge the particle surface further. The thereby intensified mass transfer facilitates the release of molecules such as proteins, lipids, sugars, vitamins, antioxidants, phyto-chemicals and dietary fibres. Ultrasonically generated shear forces improve the penetration of the solvent into the cellular matrix of the botanical matter and improve the permeability of the cell membranes, respectively. These mechanisms of power ultrasonics are responsible for the significant process intensification achieved when ultrasonication is applied for botanical extraction.
- high yields
- premium quality extracts
- highly efficient, rapid process
- low operating costs
- reproducible results
- linear scalability
- simple & safe operation
Get Technical Information on Hielscher Ultrasonic Extractors and their Advantages!
Hielscher Ultrasonics designs, manufactures and distributes high-performance ultrasonic extractors for batch and continuous processing at any production scale. Besides highest technical standards and outstanding robustness and 24/7/365 operation for high efficient operation, Hielscher ultrasonicators are easy and reliable to operate. High efficiency, smart software, intuitive menu, automatic data protocolling and browser remote control are just a few features that distinguish Hielscher extractors from other extraction equipment.
Advantages of Hielscher Ultrasonic Extractors
- Higher yields
- Rapid extraction process – within minutes
- High quality extracts – mild, non-thermal extraction
- Green solvents (water, ethanol, glycerin, vegetable oils etc.)
- Plug ‘n’ play – Set-up and train within hours
- High throughput – For large scale extract production
- Batch-wise or continuous inline operation
- Simple set-up – Supports multiple voltages, and only a four hose hookup
- Linear scale up – add another ultrasonic system in parallel to increase capacity
- Remote monitoring and control – via PC, smart phone or tablet
- No process supervision required – Set-up and run
- High-Performance – designed for continuous 24/7 production
- Robustness and low maintenance
- High quality – designed and built in Germany
- Quick load and unload between batches
- Simple and safe to run
- Solvent-less or solvent-based extraction (water, ethanol, vegetable oils, glycerin, etc.)
- No high pressures and temperatures
- ATEX-certified explosion-proof systems available
- Easy to control (also via remote control)
Solvents for Ultrasonic Extraction
Choose the ideal solvent for your extraction process: water, water-alcohol mixture, isopropyl alcohol, hexane, ethanol, methanol, butane, vegetable oils, glycerine,
non-toxic solvents as well as any other standard solvents are compatible with ultrasonic extraction.
Ultrasonic Cold-Water Extraction: Although water is technically a solvent, the so-called universal solvent, an water-based extraction is in general considered as a non-solvent extraction. An ultrasonic solvent-free extraction does not require any foreign substances. The slurry of water and plant material is sonicated to break the plant’s cell walls so that the bioactive molecules are released into the water (solvent). Sonication is a pure mechanical method, which does not chemically alter the raw material and the extract. Therefore, ultrasonic extraction is the preferred technique to produce high-quality botanical extracts.
The table below gives you an indication of the approximate processing capacity of our ultrasonic extractors (batch and flow-through processing):
|Batch Volume||Flow Rate||Recommended Devices|
|1 to 500mL||10 to 200mL/min||UP100H|
|10 to 2000mL||20 to 400mL/min||UP200Ht, UP400St|
|0.1 to 20L||0.2 to 4L/min||UIP2000hdT|
|10 to 100L||2 to 10L/min||UIP4000hdT|
|n.a.||10 to 100L/min||UIP16000|
|n.a.||larger||cluster of UIP16000|
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Literature / References
- Petigny L., Périno-Issartier S., Wajsman J., Chemat F. (2013): Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.). International journal of Molecular Science 14, 2013. 5750-5764.
- Fooladi, Hamed; Mortazavi, Seyyed Ali; Rajaei, Ahmad; Elhami Rad, Amir Hossein; Salar Bashi, Davoud; Savabi Sani Kargar, Samira (2013): Optimize the extraction of phenolic compounds of jujube (Ziziphus Jujube) using ultrasound-assisted extraction method.
- Dogan Kubra, P.K. Akman, F. Tornuk (2019): Improvement of Bioavailability of Sage and Mint by Ultrasonic Extraction. International Journal of Life Sciences and Biotechnology, 2019. 2(2): p.122- 135.
- Sitthiya, K.; Devkota, L.; Sadiq, M.B.; Anal A.K. (2018): Extraction and characterization of proteins from banana (Musa Sapientum L) flower and evaluation of antimicrobial activities. J Food Sci Technol (February 2018) 55(2):658–666.
- Ayyildiz, Sena Saklar; Karadeniz, Bulent; Sagcanb, Nihan; Bahara, Banu; Us, Ahmet Abdullah; Alasalvar, Cesarettin (2018): Optimizing the extraction parameters of epigallocatechin gallate using conventional hot water and ultrasound assisted methods from green tea. Food and Bioproducts Processing 111 (2018). 37–44.
- V. Lobo, A. Patil,A. Phatak, N. Chandra (2010): Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognosy Reviews 2010 Jul-Dec; 4(8): 118–126.