Mass production of microalgae for nutritional purposes

The rapid population growth has contributed to increased food and water consumption. To meet the continuously growing demand for food supplies, it is imperative to increase food productivity and search for alternative food sources. The current agricultural practices and food production systems pose several negative environmental impacts, such as soil erosion, water, and soil contamination, deforestation, and air pollution. As an alternative, microalgae have emerged as a promising feedstock for food production. Microalgae are a diverse group of photosynthetic microorganisms that present a wealth composition in terms of proteins, carbohydrates, pigments, vitamins, and lipids, essential compounds for human nutrition. Moreover, microalgae present higher growth rates compared with terrestrial crops and use nonarable land for growth. These characteristics make microalgal cultures an environmentally sustainable alternative as a food and feed source. Nevertheless, the mass production of microalgae faces some challenges within the different stages of the productive process: (i) the production and accumulation of interest compounds depend on the operation mode and cultivation conditions; and (ii) in the harvesting and processing (drying, cell disruption, and compound extraction) phases, many methods, with different efficiencies and associated costs, can be adopted, and the selection of the adequate methodology should take into account many aspects, from microalgal strain to final product application and the regulations established for the obtained product. This chapter highlights the main applied techniques and options that should be considered within the different stages of microalgal biomass processing, namely drying, cell disruption, and extraction of compounds that can be used in food and feed industries.