# Green Extraction of Valuable Compounds from Rubber Seed Trees: A Path to Sustainability
## 7 Green Extraction of Rubber Seed Oil
### Supercritical Fluid Extraction (SFE)  
Supercritical Fluid Extraction (SFE) is regarded as a very promising and environmentally friendly method for the extraction of bioactive chemicals from rubber seed plants, as highlighted by [PERSON] et al. [66]. This novel approach utilizes the distinctive attributes of supercritical fluids, which are substances that are kept at temperatures and pressures beyond their critical points, hence displaying features that lie between those of gases and liquids. Carbon dioxide (CO\({}_{2}\)) is generally recognized as the most extensively used supercritical fluid due to its non-toxic, non-flammable, and easily accessible characteristics.  
SFE utilizes the tunability of supercritical carbon dioxide (CO\({}_{2}\)) to selectively extract particular compounds, eliminating the need for hazardous solvents [10]. In the case of rubber seed trees, this strategy has a number of discernible benefits. The procedure involves subjecting carbon dioxide (CO\({}_{2}\)) to compression above its critical pressure, resulting in its transition to a \"supercritical\" state. This state is characterized by a combination of diffusivity similar to that of a gas and density comparable to that of a liquid [67]. Within this particular condition, CO\({}_{2}\) permeates complex structures, such as rubber seed trees, with a high degree of effectiveness, sucessfully dissolving certain substances, such as phenolic compounds, fatty acids and lipids.  
One notable advantage of SFE is its ability to function at lower temperatures, hence reducing the potential destruction of heat-sensitive bioactive compounds [68]. Moreover, the process of supercritical CO\({}_{2}\) extraction exhibits a remarkable degree of versatility as it allows for precise control over pressure and temperature parameters [69]. This enables the extraction of targeted molecules while effectively excluding undesirable elements. After the extraction process, the supercritical CO\({}_{2}\) rapidly undergoes phase transition to its gaseous state, resulting in the formation of a concentrated extract that is free from solvents. This extract can be readily separated from the solvent. The lack of residual solvents enhances the quality of the extracted chemicals [70].  
However, the implementation of SFE does provide a series of difficulties. According to [PERSON] et al. [71], the financial obstacle that may arise from the initial investment in equipment, namely the high-pressure systems required to sustain supercritical conditions, may be significant. Furthermore, thorough study and testing is necessary due to the complexities involved in optimizing extraction parameters for various kinds of rubber seed trees and its compounds. In spite of the obstacles faced, the sustainable and targeted characteristics of SFE position it as an environmentally friendly substitute for traditional extraction methods. This aligns harmoniously with the growing need for extraction techniques that are both environmentally responsible and efficient in obtaining bioactive compounds from rubber seed trees.  
Furthermore, the intricate nature of optimizing extraction parameters for various species of rubber seed trees and their corresponding chemicals need comprehensive investigation and empirical analysis. Notwithstanding these obstacles, the sustainable and discerning characteristics of SFE establish it as an ecologically sound alternative to traditional extraction methodologies, thereby harmonizing with the increasing need for environmentally conscious and effective extraction approaches within the domain of bioactive compounds derived from rubber seed trees.