Chinese Tallowtree Seed Protein
1. Composition and properties of Chinese tallowtree seed protein
The amino acid content of Chinese tallow tree protein is arginine, aspartic acid, and glutamic acid; the rat feeding experiment proves that the protein is insufficient in lysine and methionine; its nutritional value is better than that of wheat protein; two When two proteins are used in combination, there is an obvious complementary effect.
2. Physical and chemical properties of Chinese tallowtree seed protein
The solubility of tallow seed protein is different under different pH conditions, which is a U-shaped curve, and the solubility is the smallest at around pH5. From this, it can be seen that the isoelectric point of black tallow seed protein and soybean protein is about 5. In addition, the solubility of tallow seed protein is higher than that of soybean protein isolate, indicating that black tallow seed protein has better solubility. This may be because tallow seed protein and soybean protein have different amino acid composition and protein types, such as albumin, globulin and gliadin, etc. in different proportions. Both tallow seed protein and soybean protein have high water-holding and oil-holding properties, and tallow seed protein is significantly higher than soybean protein. This may be due to the relatively high solubility of tallow seed protein, which facilitates the diffusion of protein to the air/water and oil/water interfaces and improves its surface activity.
Protein-stabilized foams are generally formed by whipping and shaking protein solutions. The foaming ability of proteins is mainly determined by their soluble fraction. High protein solubility is a prerequisite for good foaming ability and stability, but insoluble protein particles can also play a beneficial role in stabilizing foams due to their Increased surface viscosity. The foaming property of tallow seed protein increased with the increase of concentration. The foam stability of tallow seed protein at each concentration was higher than that of soybean protein after 30min and 60min, that is, the foam disappearance rate of soybean protein was significantly higher than that of blackberry seed protein after whipping. Generally, protein has good foamability, but its stability is not necessarily good. Sapium seed protein has good foamability and foam stability at the same time, and it is expected to be used in foods such as bread, ice cream, and custard.
Emulsification is a liquid-liquid two-phase system in which hydrophobic droplets are surrounded by the liquid phase. Protein isolate has the amphiphilic characteristic structure of an emulsifier, and contains both hydrophilic groups and lipophilic groups in the protein molecule. It can be used as a surfactant to stabilize the emulsified state and prolong the shelf life when used in food processing. There was no difference between the emulsification of tallow seed protein and soybean protein, and the emulsification stability of tallow seed protein was higher than that of soybean protein at 10 min, but the emulsification stability of tallow seed protein was lower than that of soybean protein after 20 min and 30 min. The reason may be that the different types of protein, the presence of sugar and low molecular surfactant affect the emulsification stability.
