Characterization of Microalgal Carotenoids by Mass Spectrometry and Their Bioavailability and Antioxidant Properties Elucidated in Rat Model

Of the total carotenoids in respective algal samples, β-carotene in Spirulina platensis was 69.5%,
astaxanthin and its esters in Haematococcus pluvialis was 81.38%, and lutein in Botryococcus
braunii was 74.6%. The carotenoids were characterized by mass spectrometry. A time-course
study of carotenoids in rats after administration of microalgal biomass showed peak levels in
plasma, liver, and eyes at 2, 4, and 6 h, respectively. β-Carotene accumulation in Spirulina-fed rats
was maximum in eye tissues at 6 h. Similarly, levels of astaxanthin and lutein in Haematococcusand
Botryococcus-fed rats were also maximal in eye tissues. Astaxanthin from H. pluvialis showed
better bioavailability than β-carotene and lutein. The antioxidant enzymes, catalase, superoxide
dismutase, peroxidase, and TBARS were significantly high in plasma at 2 h and in liver at 4 h,
evidently offering protection from free radicals. This study implies that microalgae can be a good
source of carotenoids of high bioavailability and nutraceutical value.