Extraction of Bioactive Compounds from Supercritical Carbon Dioxide

The application of supercritical fluid extraction system (SFE) on the recovery of key bioactive compounds from plant matrices provides many advantages over typical organic solvent extraction procedures, notably in terms of environmental issues. Due to its cleanliness and environmental friendliness, SFE has grown in favor as a "green" processing technology in recent years. It is simpler to collect extracts offline and relate SFE to other analytical methods such as gas chromatography, HPLC, and online supercritical fluid chromatography when SFE is performed with pure or modified CO2. Increasing emphasis is being paid to supercritical carbon dioxide (SC-CO2) in the search for ecologically friendly solvents that may be used in a variety of applications. Supercritical fluid carbon dioxide is nontoxic, inexpensive, combustible, and non-polluting, making it an ideal solvent for extracting natural resources. When compared to more conventional methods like steam distillation and Soxhlet, SC-CO2 extraction offers a rapid, simple, and cost-effective solution. When it comes to employing SFE technology, there are a number of challenges that need to be solved. Traditional extraction methods have also been compared to SFE. SFE procedures may be made more efficient with the aid of this paper's practical guide.

Different enterprises, notably the food and pharmaceutical industries, employ large amounts of solvents to isolate various important bioactive compounds. The recent decade has seen a lot of attention paid to environmentally friendly, efficient, and sustainable extraction methods. Supercritical CO2 extraction (SC-CO2), ultrasound aided extraction (UAE), and microwave assisted extraction (MAE) are three non-traditional approaches that might provide considerable improvements (MAE). "Green Chemistry" has emerged in recent years, drawing attention to environmentally-friendly processes [1]. This necessitates the development of a more efficient extraction process. about 300 plant species were studied using the Supercritical Fluid Extraction (SFE) method in the past 17 years (from 2000 to 2017). SFE research focuses mostly on plant material [2,3]. Many of these plants' beneficial, pure components are already being employed to benefit human health and nutrition [4]. Due to CO2's great flexibility, non-explosive, non-flammable, non-toxic, and cost-effective properties, it is the most often used supercritical solvent [5]. Separation from solutes is also straightforward. The low critical temperature of CO2 makes it a solvent. Thermally unstable compounds may be degraded using low-critical temperature solvents rather than standard liquid solvents. These solvents are particularly popular in the pharmaceutical and natural goods industries. Simple extraction from the extract is an advantage of using low-critical temperature solvents. Supercritical carbon dioxide (SC-CO2), which is a hybrid of a liquid and a gas, offers many advantages over traditional liquid solvents. Figure 1 shows CO2's pressure-temperature phase diagram. A pressure-temperature phase diagram depicts the temperature and pressure requirements for CO2 in various stages. The fluid is referred to be supercritical if it is over the critical temperature and pressure. Carbon dioxide has a melting point of 31.1°C and a pressure of 73 atm. An infinite isothermal compressibility produces a very rapid change in density with temperature and pressure when the fluid is near to its critical point This fluid's dissolving capability may be precisely manipulated by varying the temperature and/or pressure of the supercritical fluid. Because of this, various fractions may be extracted from natural sources by adjusting the temperature and pressure of the extraction process.

Extraction of bioactive components from natural sources has seen an increase in the utilization of supercritical fluids, in particular CO2, due to recent advances in the technique's key advantages. The sfc purification is often utilized for the extraction of bioactive compounds because of its "health and safety" and environmental qualities, as well as the rising concern about the presence of organic solvent residues in items meant for human consumption. The solvating properties of supercritical fluid, which are achieved by applying pressure and temperature greater than the fluid's critical point, are the basis for the supercritical fluid extraction method.

Read More

Safe and Effective CO2 Extraction Methods

Supercritical CO2 extraction is a method that uses high pressure and temperature to force carbon dioxide into a different phase. Changing the temperature and pressure of a reaction with CO2 makes it possible to get a large variety of different products. When plant matter undergoes a phase transition, the relative abundances of its constituent parts may become unstable.

CO2 is Quick, Safe, and Clean.

The removal of CO2 has a positive economic impact. It allows the production of oil that is free from contaminants, easy to refine, and beneficial to the environment. Due to the solvent being stuck in the oil, procedures that employ toxic solvents may take a long time to complete. In a wide variety of applications, CO2 has shown to be the most effective commercial process gas.

CO2 allows you to "tune" the extraction process, which is especially useful when used with a device that will separate components during the extraction. Different working modes allow you to zero in on certain compounds, such as terpenes (terpenoids) and THC/CBD (cannabinoids). CO2 has many uses beyond only cleaning and preserving food, and it can even generate food- and medical-grade oils in the correct system and climate. 

The CO2 extraction technique is clean, safe, and very flexible, making it a viable option for extracting a wide variety of plant materials, including hops, kava kava, essential oils, and more.

Assessing the Productivity of the Extracting Method

When comparing the efficiency of different extraction methods, the overall yield is not very relevant.

It is common practice to collect yield information for the purposes of building financial models, calculating return on investment, etc. However, the results of any extraction process are subject to the quality of the input. Each strain of cannabis has its own unique cannabinoid profile, on top of the distinctions between Indica and Sativa. Most plants are grown for the express purpose of producing either a high quantity of THC or a high quantity of CBD, however, hybrids do exist. The amount of THC recovered as a percentage of the amount of THC in the feedstock is the most reliable measure of extraction yield.

Is There Any Advantage to Using Supercritical CO2 for Removal?

The "gold standard" in cannabis extraction procedures is supercritical CO2 extraction as it is safer, more effective, and cleaner than other extraction methods. For instance, heavy metal residues may be left behind during butane extraction. An evaluation found that cannabinoids, waxes, and rosins extracted using supercritical carbon dioxide were the purest possible. Although carbon dioxide (CO2) is a greenhouse gas that contributes to global warming, its removal from the natural environment, use in an extraction process, and subsequent return to the atmosphere do not lead to an increase in greenhouse gas emissions.

Another advantage of supercritical CO2extraction is that it allows for the separation of individual compounds. The food processing industries of such nations often include large-scale commercial facilities using a supercritical CO2 extraction. Coffee is decaffeinated using supercritical CO2 extraction equipment, which is an interesting bit of trivia to learn.

Full Variety Extracts: What Are They?

Full spectrum extracts deliver a more full flavor and effect experience. These extracts, which demand significantly more complex technology and talent to generate, will continue to be highly valuable. To determine the effectiveness and chemical equilibrium of full-spectrum extracts, it is necessary to compare the THC, cannabinoid, and terpene profiles of the feedstock and the extract. You can also check out, Thar Process.

Cannabis plants are made up of a complicated blend of compounds, and it is these chemicals that decide the outcome, taste, and scent of the flowers. The whole spectrum of cannabinoids, terpenes, and other chemicals make up cannabis flowers. Many extractors don't have the organic chemistry training needed to fully understand the intricate processes involved in making a top-notch extract. This leads them to keep making mistakes while trying to improve and purify their extracts. A THC extract that is 95% pure suggests that almost all of the plant's therapeutic characteristics were lost in the extraction procedure. Some could compare breathing an extract with up to 95% pure THC to the difference between eating manufactured food and drinking freshly squeezed fruit juice.

Read More