# Green Extraction of Valuable Compounds from Rubber Seed Trees: A Path to Sustainability
## 7 Green Extraction of Rubber Seed Oil
### Supercritical Fluid Extraction (SFE)
#### 7.1.2 Current Studies on Rubber Seed Trees by SC-CO\({}_{2}\)
These findings collectively emphasized the critical role of particle size in optimizing the supercritical carbon dioxide extraction process for rubber seed oil and illuminated the valuable chemical composition of the extracted oil. The supercritical carbon dioxide extract of rubber seeds, as analyzed by [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [88], stands out for its high content of alpha-linolenic acid (ALA), measuring at 19.22% \(\pm\) 0.21. This concentration surpasses the levels found in commonly used oils such as palm oil and soybean oil. ALA is a pivotal component of omega-3 fatty acids, which hold significant importance in human metabolism. These fatty acids not only serve structural roles in cell membranes, but also function as precursors to bioactive molecules crucial for various physiological processes. Omega-3 fatty acids, categorized as polyunsaturated fatty acids, possess notable properties that make them valuable for human health. Their easy absorption by the skin plays a key role in expediting the healing process within the body, primarily attributed to their capacity to promote angiogenesis, the formation of new blood vessels. This angiogenic effect facilitates improved blood circulation to injured areas, aiding in the delivery of essential nutrients and oxygen for tissue repair. Furthermore, studies have indicated that unsaturated fatty acids, like omega-3 fatty acids, can enhance the production of cytokines and growth factors that regulate local cellular responses to injury. These bioactive molecules play a critical role in orchestrating the body's healing mechanisms, including inflammation control, tissue regeneration, and immune response modulation. As a result, the presence of ALA in the supercritical carbon dioxide extract of rubber seeds not only underscores its nutritional value, but also suggests its potential as a natural resource for promoting health and facilitating the body's healing processes. In summary, the rich content of alpha-linolenic acid (ALA) in the supercritical carbon dioxide extract of rubber seeds highlights its significance as a source of omega-3 fatty acids, known for their multifaceted roles in human metabolism and health. The potential benefits of ALA, including its angiogenic properties and influence on cytokines and growth factors, make it a valuable component with promising applications in nutrition, skincare, and potentially in promoting healing and recovery in the human body. The extraction of rubber tree seed oil was conducted using both Soxhlet and supercritical extraction methods, with varying operational conditions also conducted by [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [88]. Among the tested conditions, it was observed that the combination of a 50 MPa pressure and a 60 \({}^{\circ}\)C temperature yielded the highest oil extraction yields. The extraction time ranged from 220 min for the condition of 35 MPa at 60 \({}^{\circ}\)C to 360 min for 24.4 MPa at 74 \({}^{\circ}\)C. Notably, there were significant differences in the composition of the extracts obtained through these methods. The extracts obtained using supercritical carbon dioxide exhibited a high degree of selectivity, particularly for alpha-linolenic acid, linoleic acid, and squalene. It is worth mentioning that while the extraction of alpha-linolenic acid required pressures higher than 40 MPa, lower pressures proved effective in obtaining squalene-rich extracts. Squalene is a valuable compound with diverse applications, including the use as a moisturizing agent in cosmeticsand as an adjuvant in vaccines. Statistical analysis of the extraction process revealed that pressure was the most critical variable in increasing oil yield, enhancing oil solubility, and extracting the main components effectively. Solubility models were employed to establish correlations between experimental data and predict the optimal conditions for extracting rubber tree seed oil.