Microalgal pigments: A source of natural food colors

Naturally sourced colorants and dyes are currently gaining demand over synthetic alternatives due to an increase in consumer awareness brought forward by health and environmental issues. Microalgae are unicellular organisms which are microscopic in size and represent major photosynthesizers with the ability to efficiently convert available solar energy to chemical energy. Due to their distinct advantages over terrestrial plants such as faster growth rates, ability to grow on non-arable land, and diversity in the production of various natural bioactive compounds (e.g., lipids, proteins, carbohydrate, and pigments), microalgae are currently gaining promise as a sustainable source for the production of natural food-grade colorants. The versatility of microalgae to produce various pigments (e.g., chlorophylls, carotenoids, xanthophylls, and phycobiliproteins) that can be commercially exploited as a source of natural colorant is there to be explored. Various growth factors such as temperature, pH, salinity, and light in terms of both quality and quantity have been shown to significantly impact pigment production. In this chapter, we comprehensively review the characteristics of microalgal pigments and factors that affect pigment production in microalgae while evaluating the overall feasibility of exploiting them as a natural source of food colorants