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.