Introduction to sunflower seed protein

Sunflower seed protein is also known as sunflower protein. It is a protein product made from defatted sunflower seed meal, after removing the hull and phenolic compounds such as chlorogenic acid and caffeic acid.

Here is the content list:

l Protein composition analysis

l Nutritional properties

l Physiological functions

l Preparation of sunflower seed protein

Protein composition analysis

The domestic sunflower seed kernel contains 21%-30% protein, and the sunflower seed meal after oil extraction generally contains more than 50% protein. Sunflower seed protein contains 55%-60% globulin, 17%-23% albumin, 1%-4% alcoholic protein and 11%-17% glutenin. The bound non-protein nitrogen and insoluble residues are less than 11% of the total nitrogen content. Sunflower seed protein has a solubility of 20%, 50%-60%, and 3% in aqueous, salt, and ethanol solutions respectively. The molecular mass of sunflower seed protein was found to range from 10 to 450 kDa by gel chromatography, ultrafiltration, and electrophoresis, and the molecular mass of the main component was 125 kDa, while the average molecular mass was 180 kDa, and it contained 6 to 7 protein components. The isoelectric point of sunflower seed protein is pH 4.0.

Nutritional properties

The chemical composition of sunflower seeds varies somewhat depending on the variety and growing environment. Sunflower seed kernels produced in China usually contain 40% to 68% fat, 21% to 30% sunflower seed protein, 2.0% to 6.5% carbohydrates, 6.0% crude fiber, and 3.2% to 5.4% ash. After oil extraction, sunflower seed meal generally contains 29%~43% crude protein, 4%~15% crude fat, 7%~23% cellulose, 3%~19% water, and 7%~10% ash. Sunflower seed protein's amino acid composition, the content of lysine is higher than that of cereal protein but compared with soybean protein and animal protein is a little lower, other various amino acids The other amino acids are well balanced. When comparing the amino acid composition with FAO values, all essential amino acids are higher or similar to FAO values, except lysine, which is the first limiting amino acid in sunflower seeds. Although low in lysine, its effective lysine content can be as high as 90%. Sunflower seed protein is rich in sulfur-containing amino acids such as methionine and has a good digestibility (90%) and a high biomass value (60%) compared to most vegetable proteins.

Physiological functions

Sunflower seed protein has good water absorption, oil absorption, emulsification, and foaming properties. Sunflower seed powder can absorb 170% of water and 208% of oil, and its oil absorption is higher than that of soy protein. Sunflower seed protein concentrates and isolates have foaming and mixing properties similar to fresh egg whites.

Preparation of sunflower seed protein

Sunflower seed protein concentrate is prepared by crushing sunflower seed meal after oil extraction and extracting it with 70% ethanol, acid solution, and other solvents to remove chlorogenic acid, water-soluble sugar, and inorganic salts from the raw material, and then using the production process of soybean protein concentrate to produce sunflower seed protein. After the extraction, the protein extract was centrifuged and adjusted to pH 4~4.2 with 0.5mol/L HCl solution and left for 30min to precipitate the protein. Then centrifuged to obtain protein paste, then blended, homogenized, and spray dried to obtain isolated protein.

The above is our introduction to the basic information and functions of sunflower seed protein.