α-Linolenic fatty acid
Abbreviations
- ALA
Synonyms
- cis,cis,cis-9,12,15-octadecatrienoic acid
Description
Represents an 18-carbon polyunsaturated fatty acid with three double bonds. It is the primary plant-based omega -3 fatty acid, found abundantly in flaxseed (linseed), chia seeds, walnuts, and hemp seeds.
Nutritional potential:
ALA is an essential fatty acid, meaning it cannot be synthesized by the human body and must be obtained through the diet. It serves as a precursor for the synthesis of longer-chain omega -3 like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), although the conversion rate in humans is relatively low. It is associated with cardiovascular benefits, reduced inflammation, and improved endothelial function.
Biodiesel potential:
The presence of three double bonds makes ALA highly problematic for fuel stability. While it drastically lowers the melting point (approx. -11°C) and provides excellent cold-weather operability by reducing the cold filter plugging point (CFPP), it is extremely susceptible to rapid oxidation, polymerization, and gum formation (very poor oxidation stability, OS). It also significantly reduces the cetane number (CN). Feedstocks high in ALA (like linseed oil) are generally avoided or require heavy blending and antioxidant treatment for standard biodiesel use.