Valorization of microalgal biomass for food

Microalgae are considered as a valuable source of bioactive components such as proteins, carbohydrates, vitamins, pigments, and essential fatty acids with multiple applications in the food and fuel industries. Microalgal-derived components can be used both as functional food and as nutritional additives. These microorganisms can be appraised as a sustainable resource because of their interesting characteristics such as high growth rate, ability to fix carbon dioxide, no soil requirement, ability to grow throughout the year, and biodegradability. The critical steps for the valorization of microalgal biomass include the selection of suitable strains of microalgae, cultivation, growth, harvesting, pretreatment, extraction, and purification. The factors affecting the accumulation and thus yield include temperature, pH, composition, mixing, etc. Although some microalgae species have been utilized as food sources for over a thousand years, their commercialization is still not accomplished. Integrated technologies for microalgae cultivation are currently being pursued to isolate various biologically active substances from biomass to improve the profitability of algae development. The ability to control the biosynthesis of biologically valuable compounds in environments of intensive culture growth is required to implement this form of production. More research and data are necessary, especially for new microalgal strains, increased accumulation of desired content in the cell (genetic engineering), and finally, the up-gradation of downstream processes. To make the process economically feasible, integration of the whole process and extraction without degrading other by-products is required.