Carotenoids are fat soluble pigments, normally red, yellow or orange, that have strong antioxidant activity.
We have developed environmentally sustainable organic processes for the enclosed production of carotenoids from a range of microalgae. These carotenoids (astaxanthin, β-carotene, lutein, fucoxanthin) are accessory photosynthetic pigments of microalgae.
- Astaxanthin is a natural antioxidant pigment that has been reported to delay ageing, prevent degenerative diseases, cancers, and stimulates the immune system by detoxifying toxic free-radicals.
- β-carotene is the precursor of vitamin A, which is produced by the human body for good eye health and vision, healthy skin and mucus membranes, our immune and antioxidant systems.
- Lutein helps to maintain a normal visual function by absorbing and attenuating blue light striking the retina.
- Fucoxanthin has been reported to act as a non-stimulatory fat loss agent and also reported to correct abnormal glucose metabolism in the muscle tissue of diabetic patients.
Certain microalgal species are known to accumulate high levels of carotenoids while esterified with specific essential fatty acids under stressful environments, such as under nitrogen limitation and high-light intensity. Carotenoids are yellow, orange or red colour pigments that are very popular for various food applications including supplements, functional ingredients and cosmetic products. Significant sources of carotenoids include β-carotene from Dunaliella salina and astaxanthin from Haematococcus pluvialis.
Haematococcus pluvialis grows as motile bi-flagellated green cells under optimum growth conditions. Due to changes in environmental conditions, such as increased light intensity, high temperature, nutrient limitation or high salt concentrations, the healthy green cells undergo morphological and biochemical changes as their survival strategies. They turn into red cysts, lose their motility, increase cell size, thicken cell walls, and induce carotenogenesis. In particular they accumulate significant amounts of astaxanthin esters that may constitute up to 95% of the total carotenoids.
Commercially, Haematococcus pluvialis is cultivated as a two-stage process under photoautotrophic conditions. The first (green) phase is maintained under low light, as most of the strains are sensitive to light, for induction of carotenogenesis. This first phase is focussed on generating enough actively growing green biomass, which then after gentle harvesting, is transferred to the second (red) phase which consists of a stress medium and/or high-light condition for cellular morphogenesis with appropriate biochemical changes, especially the accumulation of carotenoid astaxanthin.