Sunflower-seed protein is also expressed as sunflower seeds protein and also known as sunflower protein. Such protein product is made from defatted sunflower seed cake as a raw material after removal of the shell and phenolic compounds, such as chlorogenic acid and caffeic acid. The main component is globulin (approx. 70%-79%), followed by albumin and a small amount of gluten and prolamin. In the amino acid composition, the content of lysine is low, while the content of other essential amino acids is high. In the amino acid composition of sunflower seeds protein, the content of lysine is higher than that of cereal protein, but it is slightly lower than that of soybean protein and animal protein. It shows a good balance in terms of other amino acids. When its amino acid composition is compared with the FAO value, the content of other essential amino acids is higher than or similar to the FAO value, except for the lysine content. Therefore, lysine is the first limiting amino acid of sunflower seeds. Although the lysine content is low, its effective lysine content is up to 90%. Sunflower seeds protein is rich in sulfur-containing amino acids, such as methionine. Compared with most plant proteins, sunflower seeds protein has good digestibility (90%) and higher biological value (60%).