Lutein production from biomass: marigold flower versus microalgae

Lutein is a yellow xanthophyll existing in higher plants and other photoautotrophic organisms. It is widely used as a feed and food additive. Lutein benefits human health such as the amelioration of cardiovascular diseases, cancers and age-related macular degeneration (AMD). The lutein marketing size is expected to achieve $308 million USD by 2018.
There have different types (trans/cis) and forms (free/ester) of lutein with commercial lutein being the all-trans structure. Lutein products have different forms: free lutein (Kemin) and lutein esters (Cognis). Lutein can be easily absorbed due to its relatively small size when compared with lutein esters though the latter have high tolerance to heat and light. Both benefit human health, but there are not enough evidences to distinguish which is better.
The lutein content in microalgae is higher than that of the marigold flower because lutein esters are major form that exists in the marigold petals. After alkali treatment, free lutein content of marigold flower (20 g/kg) is 2-4 times higher than microalgae (5-10 g/kg). The simulation of lutein production is based on 1 ha land (104 m2). The annual lutein production of microalgae (350-750 kg/ha) is 3-6 times higher than marigold flower (120 kg/ha). However, because of the relatively low lutein content in microalgae, it required more resources during whole production of lutein to produce 1 kg. In order to commercialize, new strains are required. Furthermore, the mechanical disruption methods should be replaced by chemical or biological methods due to the energy consumption difference in the order of 5. A suitable extraction method that minimizes the use of large quantities of extractants and energy is required.