Linoleic fatty acid
Abbreviations
- L
Synonyms
- cis,cis-9,12-octadecadienoic acid
Description
Represents an 18-carbon polyunsaturated fatty acid with two double bonds. It is the most abundant polyunsaturated fatty acid in nature and the primary omega -6 fatty acid, found in high concentrations in many vegetable oils (e.g., sunflower, corn, soybean, and safflower oils).
Nutritional potential:
Linoleic acid is an essential fatty acid, meaning the human body cannot synthesize it and it must be obtained through the diet. It is vital for maintaining cell membrane integrity, skin barrier function, and serves as a precursor to arachidonic acid, which is further converted into important signaling molecules (eicosanoids) involved in inflammation and immunity. While essential for survival, an excessive intake of linoleic acid relative to omega -3 fatty acids is debated to potentially promote a pro-inflammatory state.
Biodiesel potential:
In fuel applications, the presence of two double bonds in linoleic acid presents a trade-off. It significantly lowers the melting point (approx. -5°C), which greatly improves cold-weather operability by reducing the cold filter plugging point (CFPP). However, it makes the biodiesel highly susceptible to oxidation and degradation over time (poor oxidation stability, OS) and lowers the cetane number (CN), which negatively affects ignition quality compared to monounsaturated or saturated fats.