... ) Appearance: fine green powder 2) Taste: mild, like seaweed 3) Protein: >65% Spirulina is single-celled blue-green algae that grows ... any other algae. Spirulina is 65% to 71% all-vegetable protein, with all essential amino acids in perfect balance. In comparison ... , beef is only 22% protein. It is also rich in beta-carotene, iron, vitamin B12 ...