Abstract
By the year 2050, the human population of the Earth is projected to reach 9.8 billion. Consequently, there will be the need to ensure food security. This has stimulated a search for 'alternative foods' as a means to diversify the types and nutritional quality of food and feed currently available. Proteins are an important food nutrient for which alternative sources are highly being sought. Interestingly, algae have been demonstrated to be an important alternative protein source. From the perspective of agriculture, the cultivation of algae lends itself to faster growth compared to plants. From a nutritional perspective, algae protein contains all the essential amino acids needed in diets. These make algae a good option for meeting protein needs of a growing population, and some algal species have already found use in food, animal feed, cosmetics and therapeutics. However, achieving efficient extraction of specific components such as protein from algae is often challenging due to the presence of a robust cell wall in most algae. Consequently, effective methods for disrupting algal cell walls are necessary to facilitate the extraction of intracellular algae components. Also, the development of robust and high throughput analyses and quantification methods for algae protein are crucial in the research and development of algae as an alternative protein source. The currently available scientific literature on protein extraction methods and applications, together with the nutritional quality of the proteins that can be obtained from macro- and micro-algae, are reviewed in this chapter.