Photo-Oxidative Stability of Aqueous Model Systems Enriched with Omega-3 Long-Chain Polyunsaturated Fatty Acid-Rich Microalgaeas Compared to Autoxidative Stability

Several species of microalgae are promising as an alternative source of omega-3 long-chain polyunsaturated fatty acids(n-3 LC-PUFA). Photoautotrophic species show the greatest potential, since incorporating them into food products leads tooxidatively stable products; however, the presence of photosensitizers could reduce the shelf-life due to the appearance of photo-oxidation on exposure to light. This study investigated the oxidative impact of illumination for aqueous model suspensions enrichedwithPhaeodactylum(phototrophic microalgae???containing potential photosensitizers) andSchizochytrium(heterotrophicmicroalgae???lacking photosensitizers) during storage for 28 days at 37 degrees C. Primary (peroxide value) and secondary (volatileswith gas chromatography (GC)-mass spectrometry) oxidation products, n-3 LC-PUFA content (GC), and pigments (high-pressureliquid chromatography) were assessed. The results showed that photo-oxidation did not cause oxidative instability forPhaeodactylumsamples compared with strong autoxidation inSchizochytriumsamples. For thePhaeodactylum-enriched suspensions, only minimalphoto-oxidation could be detected and the n-3 LC-PUFA content remained stable throughout storage regardless of illumination

Automated summary

This study investigated the oxidative impact of illumination on photoautotrophic microalgae and heterotrophic microalgae during storage, and found that photo-oxidation had minimal effect on the oxidative stability of photoautotrophic microalgae, while causing strong autoxidation in heterotrophic microalgae.