# Green Extraction of Valuable Compounds from Rubber Seed Trees: A Path to Sustainability
## 6 Valuable Compounds in Rubber Seeds
### Phytosterols  
Rubber seed oil is distinguished by its significant content of phytosterols, plant compounds structurally similar to cholesterol. [PERSON] et al. [49] found that the contents of P-sitosterol are 12.13 and 11.22 mg/g in crude and refined rubber seed oil, respectively. These natural compounds have garnered attention for their potential health benefits, particularly their cholesterol-lowering effects, making them valuable components in functional food products. Phytosterols, also known as plant sterols or stanols, share a structural resemblance to cholesterol, which is a vital component of cell membranes in humans [50]. However, phytosterols differ in their origins and sources, primarily from plants. Their structural similarity to cholesterol allows them the ability to compete with cholesterol for absorption in the intestinal tract.  
The primary health benefit associated with phytosterols is their cholesterol-lowering effect [51]. When consumed, phytosterols interfere with the absorption of dietary cholesterol in the gut. By competing with cholesterol for absorption, phytosterols effectively reduce the amount of cholesterol that enters the bloodstream [52]. This mechanism has been well documented in clinical studies, demonstrating that regular consumption of phytosterol-rich foods can reduce low-density lipoprotein (LDL) cholesterol, often called \"bad\" cholesterol. This effect is particularly significant for individuals with elevated cholesterol levels and those at risk of heart disease.  
Phytosterols have found a prominent place in the formulation of functional food products to promote heart health [53]. Functional foods offer specific health benefits beyond their essential nutritional value. Phytosterol-enriched foods, such as spreads, margarine, yoghurt, and cereal bars, have been developed to provide a convenient and effective means of incorporating these cholesterol-lowering compounds into one's diet. These products are often marketed as heart-healthy options for individuals looking to manage their cholesterol levels naturally.  
Phytosterol-enriched foods have also received regulatory approval in various countries, including the United States and the European Union, as practical dietary tools for managing cholesterol [54]. Health organizations like the American Heart Association endorse consuming phytosterol-rich foods as part of a heart-healthy diet. Phytosterols can also work synergistically with other heart-healthy nutrients, such as soluble fiber and omega-3 fatty acids, further enhancing their cholesterol-lowering potential [55]. Functional foods that combine these ingredients offer a comprehensive approach to cardiovascular health.  
In conclusion, phytosterols found in rubber seed oil might represent a valuable natural resource with notable health benefits, particularly in managing cholesterol levels. Their incorporation into functional food products provides consumers with accessible and effective means of promoting heart health. The cholesterol-lowering effects of phytosterols underscore their potential contribution to reducing the risk of cardiovascular disease, making them a key player in functional foods and nutritional interventions for heart health.