Microalgae as a source of nutraceuticals

Microalgae have been recognized as rich sources of proteins, omega-3 and -6 fatty acids, carbohydrates, pigments, vitamins, minerals and a variety of bioactive peptide molecules with marketable nutraceutical and potential pharmaceutical properties. Notable biological activities of microalgal-derived compounds include antioxidant, antibacterial, antifungal, antiviral, antiparasitic, angiotensin I-converting enzyme inhibitory (ACE-inhibitory), anti-proliferative, anti-elastase, anti-trypsin, anti-chymotrypsin, myofibroblast differentiation inducing and hepatic fibrosis inhibitory activities. The global demand for microalgal research is largely drawn towards the production of alternative biofuels. However, several decades of research on the nutraceutical and pharmaceutical benefits of microalgae, combined with the present interest for alternate biofuels production, have revolutionized the concept of microalgal biorefining. One over-riding attribute of microalgae is that they have high growth rates compared to terrestrial plants, and may be cultivated photoautotrophically, with meagre amounts of inorganic nutrients. Microalgae cultivation systems may also be based on non-arable land and use non-potable water, brackish water, sea water, and even industrial waste water carrying CO2. Better utilization of such underused and widely available resources is one approach to a microalgal bio-refinery process, which conceptually offers an economically attractive and potentially environmentally sustainable means towards the production of microalgal-derived nutraceuticals. This chapter presents the past, current and future developments of microalgal-derived nutraceuticals, with particular emphasis on their type, source and application in food and other industrial sectors.