Fatty Acid Chemistry

Fatty acids are classified by saturation: saturated (no double bonds), monounsaturated (one double bond), or polyunsaturated (multiple double bonds). Fatty acid chain length determines absorption pathway: chains of 10 carbons or fewer enter the bloodstream directly via the portal vein, while longer chains route through the lymphatic system. Lauric acid (C12) is borderline between medium- and long-chain classification: approximately 25% absorbs directly via portal absorption while 75% routes through the lymphatic system. The reactive double bonds in unsaturated fats make them prone to oxidation and rancidity when exposed to oxygen, heat, or light.