Long chain fatty acids
Abbreviations
- LCFA
Synonyms
- Long-chain fats, Long-chain triglycerides (LCT)
Description
Represents a broad group of fatty acids with aliphatic tails of 13 to 21 carbon atoms. This group encompasses the vast majority of naturally occurring fatty acids in human diets and commercial oils, including saturated (e.g., myristic C14:0, palmitic C16:0, stearic C18:0) and unsaturated forms (e.g., oleic C18:1, linoleic C18:2).
Nutritional potential:
In human nutrition, LCFAs are the primary source of dietary fat. Unlike short- and medium-chain fatty acids, LCFAs require bile salts for digestion and are absorbed via the lymphatic system, packaged into chylomicrons before entering the bloodstream. Their health impacts vary drastically depending on their degree of unsaturation: saturated LCFAs are often linked to increased cardiovascular risk, while monounsaturated and polyunsaturated LCFAs are generally considered heart-healthy. They are essential for energy storage, hormone production, and forming the lipid bilayer of cell membranes.
Biodiesel potential:
In fuel applications, LCFAs are the standard building blocks of conventional biodiesel, as they make up the bulk of common feedstocks like soybean, rapeseed, palm, and animal tallows. Their specific properties depend heavily on the degree of unsaturation. Generally, LCFAs provide the ideal energy density (heating value) and kinematic viscosity required for diesel engines. Saturated LCFAs offer a high cetane number (CN) and oxidation stability (OS) but poor cold flow properties, whereas unsaturated LCFAs improve cold-weather operability at the cost of oxidative stability.