How Fish Oil and Krill-Type Oils Break Down Differently When Exposed to Oxygen

Researchers used advanced lab techniques (RPLC-Q-TOF) combined with computer simulations to study how marine oils oxidize over time at a molecular level. They tracked the formation of oxidized fats in both triglyceride-type oils (like standard fish oil) and phospholipid-type oils (like krill oil).

In oils high in triglycerides, oxidation products spiked quickly, peaking around day 2, then declined as the damaged molecules broke down further. In contrast, oils containing meaningful amounts of phospholipids stayed much more stable overall, because the phospholipids seemed to “absorb” oxidative damage first, protecting the triglycerides.

Computer modeling showed that phosphatidylcholine (PC), a type of phospholipid with a bulkier head structure, formed a better physical barrier against oxygen than phosphatidylethanolamine (PE). Even very small amounts of a fully saturated phospholipid (with no unsaturated fat in it) could help block oxidation-triggering reactions, while phospholipids containing marine omega-3 fats offered less protection because they themselves oxidized quickly.