In vitro bioaccesibility of lutein and zeaxanthin from the microalgae Scenedesmus almeriensis

Aim of the study: To assess the in vitro bioaccessibility of lutein and zeaxanthin from lyophilised biomass and lutein-enriched extracts in olive oil produced from a lutein overproducing strain of Scenedesmus almeriensis. Results: Lutein and zeaxanhin were mostly present in free form (>90-95%). Both xanthophylls were highly stable upon in vitro digestion, with an overall recovery above 75% (lyophilised biomass) and very low isomerization, whilst micellarization was <1% of the amount initially present and cis-isomers of lutein and P-carotene were preferentially incorporated. Using lutein-enriched extracts in olive oil, the micellarization of lutein and zeaxanthin increased dramatically reaching values up to 80-90% of the amounts initially present. Conclusion: The lyophilised biomass of S. almeriensis constitutes a very rich source of free lutein (and zeaxanthin) but poorly bioaccesible. However, oil extracts from this lyophilised biomass are highly bioaccesible and may supply amounts of lutein and zeaxanthin comparable to or higher than those provided by traditional foods. (C) 2008 Elsevier Ltd. All rights reserved.