The optimal extraction and purification methods for marigold flowers and microalgae have been proposed by Artiwan Shotipruk and Fernández-Sevilla (Ceron et al., 2008; Vechpanich and Shotipruk, 2011; Boonnoun et al., 2012). Based on data (Sections 2.3 and 3.3), assuming lutein content is 20 g/kg for marigold flowers and 5 g/kg for microalgae, 500 L hexane, 10 L ethanol, 1 kg KOH, 42.5 L water and 110 MJ energy are needed to produce 1 kg lutein from marigold flowers, and 6000 L ethyl ether, 80 kg KOH, 2000 L water, 120 L acetone, 200 L olive oil, and 2000 MJ energy are needed to achieve the same yield from microalgae. Restated, although microalgae consume less water during cultivation than marigold flowers, the extraction stage for the former consumes much more chemicals and water and requires more energy than the latter. This difference is likely due to the different ways lutein binds in the biomass; that is, the chemical bond for lutein in microalgae cells is much stronger than in marigold flowers.