Microalgae as a potential source of carotenoids: Comparative results of an in vitro digestion method and a feeding experiment with C57BL/6J mice

This study aimed to investigate Chlorella vulgaris (C. vulgaris; phototrophic and mixotrophic), and Phaeodactylum tricornutum (P. tricornutum) as a potential carotenoid source. Feed preparations containing 5, 15, or 25% of these microalgae species were applied to investigate the carotenoid bioaccessibility (in vitro digestion) as well as bioavailability in vivo in C57BL/6J mice. C. vulgaris mainly contains lutein and beta-carotene (mixotrophic), whereas P. tricornutum is rich in fucoxanthin, zeaxanthin, and beta-carotene. The diet supplemented with 5% P. tricornutum and ingestion of the 15% and 25% diet of all investigated microalgae species led to an accumulation of carotenoids and derivatives in the liver. The adipose tissue also showed carotenoids after the consumption of P. tricornutum-diets, but not after C. vulgaris ingestion. We could neither observe a significant increase nor impairment of the retinol concentration in the liver. Thus, consumption of a microalgae-enriched diet can contribute to the absorption and accumulation of microalgal carotenoids.