Protein can be divided into animal protein and plant protein according to the source, the amino acids contained in the two are different. Animal protein is mainly whey protein extracted from milk, which contains a complete range of essential amino acids and a reasonable ratio, but contains cholesterol. Plant protein is mainly derived from soy protein. The biggest advantage is that it does not contain cholesterol. According to the type and quantity of amino acids, it can be divided into three categories: complete protein, semi-complete protein, and incomplete protein.

　　Complete protein This is a type of high-quality protein. They contain a complete variety of essential amino acids, in sufficient quantities, and in an appropriate ratio to each other. This type of protein can not only maintain human health, but also promote growth and development. Such as whey protein, soy protein.

　　Although the semi-complete protein contains a wide range of amino acids, some of them cannot meet the needs of the human body. They can maintain life, but cannot promote growth and development, such as wheat gliadin.

　　Proteins such as incomplete protein cannot provide all the essential amino acids needed by the human body. They can neither promote growth nor maintain life, such as zein and legumin in peas.

　　In addition, proteins can be divided into structural proteins, regulatory proteins, contractile proteins, and antibody proteins according to their physiological functions.

　　Structural protein: proteins that make up human tissues, such as ligaments, hair, nails, and skin;

　　Regulatory proteins: proteins with regulatory functions, such as insulin, thyroxine, etc.;

　　Contractile proteins: proteins involved in the contraction process, such as myosin, actin, etc.;

　　Antibody protein: The protein that constitutes the body's antibodies, such as immunoglobulin.

　　Nutrition tips:

　　The relationship between amino acids and protein

　　Amino acids are the basic components of protein. Because of the different types and proportions of amino acids, the properties and functions of proteins are different. There are more than 20 kinds of amino acids that make up human protein. Among them, 9 kinds of amino acids can not be synthesized by the human body, but they are necessary to maintain life activities and can only be obtained from food. These amino acids are called essential amino acids (including: lysine , Tryptophan, phenylalanine, methionine, threonine, isoleucine, leucine, valine, histidine), lack of any of them will cause abnormal physiological functions and diseases. The rest of the amino acids can be synthesized by the human body or can be converted from other amino acids, not necessarily ingested from food, so they are called non-essential amino acids.

　　What is whey protein?

　　Whey protein is a protein extracted from milk. It contains more than forty main nutrients, mainly composed of lactoglobulin, a-lactalbumin, bovine serum albumin, immunoglobulin, etc., and is also rich in cysteine ​​amino acids and Methionine, these sulfur-containing amino acids can maintain the level of antioxidants in the body and stabilize DNA as much as possible during cell division. Experiments have shown that whey protein can also stimulate the human immune system, prevent chemical substances from causing cancer, and increase bone strength and reduce LDL cholesterol levels. Secondly, it has a fast absorption rate, which can make the nitrogen in the muscle reach its peak within a few minutes after taking it, thereby providing a large amount of essential amino acids. Third, the amino acid composition of whey protein is closer to the needs of the human body than plant protein, so it is easier to be used by the body.

　　What is soy protein?

　　Soy protein is a full-price protein, and the essential amino acids it contains can basically meet the needs, and its price is relatively cheaper. At the same time, the enzymatic hydrolysate of soy protein combined with phospholipids or chitosan can improve cholesterol metabolism, significantly reduce plasma cholesterol, triglycerides and low-density lipoproteins, without affecting plasma high-density lipoproteins, thereby reducing the incidence of coronary heart disease. In addition, there is a substance in soy protein called isoxan, which has many special functions while promoting fat decomposition and lowering cholesterol: anti-oxidation, anti-cancer, promoting bone calcification, inhibiting breast cancer cell proliferation, and preventing high blood pressure. Complications of diseases such as diabetes, diabetes, etc. In addition, isoflavones are a natural substance similar to female hormones and can be used as hormone substitutes for menopausal women. Because it is not only effective, but also very soft, unlike direct estrogen that will cause side effects. Therefore, for menopausal women and people with coronary heart disease, high blood pressure, and arteriosclerosis, plant protein is the protein of choice. Soybean is the best source of low-fat protein known so far. Soy protein is rich in 9 kinds of essential amino acids. It is water-soluble and can be dissolved in water and is easily absorbed by the body.

　　Complementary effects of whey protein and soy protein

　　Whey is rich in cysteine ​​and methionine, and when combined with soy protein lacking sulfur-containing amino acids (methionine), it can complement each other and increase the biological value of protein. After adding the right amount of whey protein, the amino acid score of soy protein isolate can reach 1.0, and its nutritional value is consistent with egg and milk protein, very close to the standard amino acid model, and it is easily absorbed and utilized by the body. Therefore, double protein has better nutritional value than single animal protein.