The consumption of microalgae is restricted to very few species, for example Spirulina, Chlorella, and Dunaliella (Jensen, 1993; Pulz and Gross, 2004). The market value of microalgal products (health foods) is estimated at US$20-25 million and it is by far the largest commercial application of microalgae (Metting, 1996). Spirulina and Chlorella are currently dominating the microalgal market. Spirulina is a source of protein that is comparable to meat and dairy products. Spirulina also contains high amounts of vitamin A and B12 (Metting, 1996).

Microalgal products to be used for human nutrition are usually sold in the form of tablets or powders (Metting, 1996; Radmer, 1996; Pulz and Gross, 2004). The pack­aged food industry, valued at US$2 trillion, is on the hunt for sustainable and natu­ral sources of fiber and healthy fats as ingredients for nutritionally high-value and — quality foods (Singh et al., 1996). Microalgal foods pioneer Solazyme-Roquette has created “high-lipid algal flour” (Daniells, 2011), intended for use as a main ingredi­ent alternative to make healthier processed foods such as chocolate milk (4.5% algal flour), frozen desserts, and even low-calorie salad dressings.

Extracts from microalgae are creating a new sector for microalgal products (Pulz and Gross, 2004). Products made from algal extracts include Chlorella health drinks and Spirulina liquid CO2 extracted antioxidant capsules. The microalgal biomass from Spirulina and Chlorella is not only used in human nutrition, but also in animal feed (Pulz and Gross, 2004), as it has been proven to support the immune system of animals. The market value of Spirulina and Chlorella is estimated at US$80 and $100 million, respectively (Radmer, 1996).