Ultrasonic Extraction Using Hemp as Raw Material
- For the cannabis sativa plant, two species can be differentiated: marijuana and hemp.
- Ultrasonic is well known as superior method to isolate cannabinoids from both, marijuana and hemp.
Hemp vs Marijuana
Cannabis is a family of plants which can be classified into C. Indica and C. Sativa. Hemp and marijuana are species of Cannabis Sativa.
When comparing Hemp vs Marijuana, there is a huge distinction; while Hemp contains a very low concentration of THC (0.3% or less), Marijuana is abundant in THC with concentrations between 15% to 40%.
Therefore, until recently hemp has been grown primarily for industrial purposes. Nowadays hemp is valued for its CBD yield, too. CBD is a non-psychoactive cannabinoid that has anti-inflammatory, anxiolytic properties. Marijuana is mainly grown for its THC content, which is used for recreational and medicinal purposes.
Hemp oil and CBD, the main cannabinoid found in hemp, are promising substances which are administered in order to help with medical conditions such as anxiety, chronic inflammation, autoimmune diseases, pain, headaches and migraine, gastrointestinal disorders, besides others.
Ultrasonic Extraction of Cannabinoids
The ultrasonic extraction technology is highly efficient to release the active compounds (i.e. cannabinoids (CBD, THC, CBG), essential oils, terpenes etc.) from the plant material such as buds, leaves, and stems.
Ultrasonic extraction outperforms conventional extraction techniques dur to various advantages:
Ultrasonically-assisted extraction (UAE) is well-known as a process intensifying technique, which improves mass transfer and releases higher yields of bioactive compounds such as cannabinoids, terpenes etc.
Ultrasonication produces high-quality extracts since ultrasonic extraction does not require the use of harsh, toxic solvents to release cannabinoids. Ultrasonic extraction can be run with water, water-alcohol mixture, alcohol or oil (olive, coconut) as solvents, for instance. This makes ultrasonically-assisted extraction (UAE) significantly environmental-friendlier.
The mild extraction conditions of UAE result in an extract, which offers the same, but intensified properties of the raw material (e.g. hemp, marijuana) – offering superior health effects, taste, and smell.
Hielscher’s ultrasonic extractors can be precisely controlled. By the full control over the process parameters such as intensity and temperature, an exceptionally high extract quality can be obtained. Since sonication is a non-thermal processing method, thermal degradation of heat-sensitive components is avoided. Extraction temperatures between 0-60°C are optimal for superior extracts.
Another benefit of UAE is the rapid process: The entire extraction process takes only minutes to release the cannabinoids from the plant cells, whilst other extraction techniques require hours or even days of processing time.
Both, investment and operational costs are minimal in comparison to alternative extractors, e.g. supercritical CO2 extractors. Ultrasonic extraction systems have a very fast RoI.
- High quality extracts
- More complete extraction
- High extraction rate
- Full-spectrum extract
- Use of various solvents
- Non-thermal (cold) method
- Rapid extraction process
- Safe and easy-to-use
- Linear scalability
High Performance Ultrasonic Extractors
Hielscher Ultrasonics’ offers small, mid-size and industrial ultrasonic processors, which can be operated 24/7. Depending on your raw material and process volume, we are able to offer you an ultrasonic extraction system that suits your needs. You can choose between batch and continuous extraction. Later scale-up to larger process capacities can be easily done since ultrasonic processes can be scaled linearly.
Hielscher’s pilot and industrial systems can deliver very high amplitudes – allowing to run amplitudes of up to 200µm reliable and continuously run in 24/7 operation. For even higher amplitudes, customized ultrasonic sonotrodes are available. The robustness of Hielscher’s ultrasonic equipment allows operations at heavy duty and in demanding environments.
As long-time experienced manufacturer of high-power ultrasonic extractors, Hielscher is your reliable partner for sophisticated extraction. We consult and assist our customers with our knowledge and guide them from feasibility testing to industrial installation.
Contact us now! We are glad to discuss your extraction requirements with you!
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- Uzma Altaf, A Rouf, Varsha Kanojia, Qudsiya Ayaz, Imtiyaz Zargar (2018): Ultrasound treatment: A novel processing technique for food preservation. The Pharma Innovation Journal 2018; 7(2): 234-241.
- Renata Vardanega, Diego T. Santos, M. Angela A. Meireles (2014): Intensification of bioactive compounds extraction from medicinal plants using ultrasonic irradiation. Pharmacogn Rev. 2014 Jul-Dec; 8(16): 88–95.
Facts Worth Knowing
Ultrasonic extraction has risen to the most effective and user-friendly technique when it comes to the extraction of bioactive compounds from botanicals. The most prominent example of successful extraction might be the isolation of CBD and other cannabinoids from cannabis.
Ultrasonic vs. Conventional Extraction Methods
Soaking in ethanol is a simple method, but it is very time-consuming, the process capacity is limited and solvent and energy costs are high. Residual solvent in the final product are interfere with the goal to produce a high-quality extract.
Extraction using a closed hydrocarbon system requires the use of fossil fuels, so that cancer-causing substances like benzene can be found in the final product.
Supercritical CO2 extraction systems are high in investment cost as well as energy consumption. Supercritical CO2 extractors require well-trained staff for operation since the high pressurized CO2 systems are hazardous to operate. When CO2 leaks it can cause asphyxiation death of the workers present.
Critical water extraction is an environmental-friendly alternative, which is slow and releases only a small fraction of the bioactive compounds.
Ultrasonic extraction is an intensifying extraction technique which can be used in combination with water (solvent-free) as well as with solvents such as ethanol, ethanol-water, glycerin, methanol, vegetable oils or other solvents of choice. Ultrasonic extraction promotes the mass transfer so that extract yields of 95-99% can be obtained. Sonication can be easily scaled up and produces a high-quality extracts.
A small-scale ultrasonic extractor such the UIP400St (400W) is capable to process a batch of up to 10L within 5-15min (depending on process parameters such as raw material (fresh or dried; buds, leaves, stems), solvent, temperature). The 2kW powerful ultrasonic extractor UIP2000hdT can be operated as inline system. In flow-through mode, the UIP2000hdT easily processes 200 to 800L/hr (also depending on process parameters).
The investment cost for an ultrasonic processor is low in comparison to a CO2 extractor. Also the energy costs for operation are neglectable. Ultrasonic extractors are very safe to operate, easy to clean and require very low maintenance.
The bioactive compounds of the cannabis (both, hemp and marijuana) plant have gained a lot of attention in the nearer past. Especially for the cannabinoid Cannabidiol (CBD) many health benefits have been shown, which reach from cancer-fighting and anti-inflammatory properties to pain-relieve and anti-depressant effects. Besides cannabidiol, the cannabis plant contains manifold other cannabinoids such as THC (tetrahydrocannabinol), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), and cannabinodiol (CBND). Cannabinoids have shown immense therapeutic potential and are in the focus of many research studies.
The interaction of the various cannabinoids and other bioactive compounds such as terpenes, polyphenols, flavonoids, and alkaloids seems to result in even better health benefits. The interplay of different terpenes, different cannabinoids and other plant compounds is called “entourage effect”. Due to this entourage effects, full-spectrum extracts, which can be successfully obtained via ultrasonically-assisted extraction (UAE), are known for exceptional therapeutic effects.
Terpenoids are essential oil components, which can be found in botanicals. The cannabis plant is very rich in terpenes. In cannabis, terpenes are made in the trichomes of the plant. The trichomes are the shiny, sticky crystals that adhere onto the leaves and buds. These trichomes are the natural defense mechanism of the cannabis plant, which protects the plant against insects and animals. Due to the fragrant smell, the terpenes act as a repellent. For us humans, the most noticeable characteristic of cannabis terpenes is their smell. These terpenes contribute to the manifold health benefits of the cannabis plant (hemp and marijuana).
Besides their aroma and scent, terpene molecules are powerful botanical substances which offer various medical benefits.
Both marijuana and hemp of the Cannabis Sativa genus contain an exceptionally amount of terpenoids and contain more than 100 different types of these substances.
Each terpene has unique properties which range from sedative to uplifting. For instance, nerolidol has sedative and anti-anxiety effects, linalool helps to manage symptoms of anxiety and arthritis, whilst myrcene is known to relieve chronic pain. The terpenes β-Myrcene, Ɣ-pinene and humulene reduce inflammation and have analgesic effects.
Various terpenes are unique to cannabis, but many of the terpenes found in cannabis are present in several other plants, too. Caryophyllene is found e.g. in green leafy veggies, hops as well as in rosemary and oregano. Limonene is the major terpene found in citrus fruits such as lemons and oranges.
The Entourage Effect
Each terpene is known for specific therapeutic effects. However, terpenes and other botanical compounds such as polyphenols and flavonoids are known to exhibit exceptional synergetic effects, which result in an improved symbiosis between cannabinoids. This interaction of various bioactive compounds is known as “entourage effect“.
The entourage effect makes terpenes more bioavailable and help the body to absorb the cannabinoids more efficiently.
Types of Bioactive Compounds
The number, concentration and variety of bioactive compounds are responsible for the medicinal properties of a botanical extract. These bioactive compounds are synthesized as secondary metabolites, which do not contribute to the growth or photosynthesis in plants. However, they are crucial for the plants’ survival and interaction with its environment. Botanical bioactive compounds can been broadly classified into the three classes of terpenes and terpenoids, alkaloids, and phenolic compounds. Phenolic compounds are the most widely distributed group of secondary metabolites in the plant kingdom and are well known and valued for their antioxidative effects. Another important class of low-molecular-weight phenolic compounds are the flavonoids, which exhibit very strong antioxidative effects, too.
The range of phenolic compounds includes phenolic acids such benzoic and hydroxycinnamic acids, flavonoids such as flavones and flavonols, lignans, and stilbenes. A full-spectrum extract (e.g. obtained by ultrasonic extraction from cannabis) includes all these different botanical compounds, which exhibit the most wide-ranging health effects.
The Working Principle of Ultrasonic Extraction
Ultrasonic extraction is based on acoustic waves (ultrasound) coupled into a liquid media. Intense ultrasound waves generate high pressure / low pressure cycles. Due to pressure differentials during the propagation of ultrasound waves through the liquid, cavitation bubbles occur. The implosion of these cavitation bubbles results in energy-dense conditions.
The conditions in proximity of imploding cavitation bubbles can be extreme – producing temperatures of up to 4500°C and pressures up to 100 MPa. The imlosion and resulting ressure differentials result in very high shear forces and turbulences in the cavitational hot spot. The combination of these factors of pressure differentials, heat differentials and shear promotes mass transfer and thereby extraction processes. By the intense ultrasonic cavitation forces, cells (e.g. of plants, bacteria, or tissue) are disrupted and the intracelular material (such as oils, lipids, proteins, and active compounds) are released into the surrounding solvent.
Ultrasonic extraction is therefore the preferred method to intensify extraction processes.