Basic knowledge of functional peptide

Functional peptide is a kind of peptide which plays an important regulatory role in vivo. It not only has the same amino acid composition as homologous protein, but also has better digestion and absorption performance than protein, so it can maintain and improve the nutritional status of protein. Peptides widely exist in organisms, which are composed of low molecular proteins with less than 50 amino acids. They play an important regulatory role in the body, so they are called bioactive peptides (also called functional peptides). The brain, gastrointestinal tract, endocrine and heart can synthesize and release peptides with functional regulation.

1 General

Peptides widely exist in organisms, which are composed of low molecular proteins with less than 50 amino acids. They play an important regulatory role in the body, so they are called bioactive peptides (also called functional peptides). The brain, gastrointestinal tract, endocrine and heart can synthesize and release peptides with functional regulation.

2 functional properties of functional peptides

The nutritional value of functional peptide the absorption effect of functional peptide in intestinal tract is the best, and in fact, most of the protein in human body is absorbed in the form of peptide. Functional peptide not only has the same amino acid composition as homologous protein, but also has better digestion and absorption performance than protein, so it can maintain and improve the nutritional status of protein.

Antihypertensive effect of functional peptide

Some functional peptides can inhibit the activity of ACE, because ace in the blood vessel can convert ACE I into ace II, which can make the peripheral blood vessels contract and blood pressure rise. In this respect, soybean polypeptide, rice polypeptide and collagen polypeptide can significantly inhibit the activity of ACE and reduce blood pressure.

Cholesterol lowering effect of functional peptide

The results showed that the functional peptides, such as soybean peptide and mung bean peptide, can reduce cholesterol in serum. They can block the re absorption of cholesterol in intestine and promote its excretion.

The effect of functional peptide on fat metabolism

Protein intake is easier to promote energy metabolism than fat and sugar intake, while functional peptide has a stronger effect on energy metabolism. Ingestion of functional peptide can accelerate the metabolism of body fat, make energy consumption faster, help to lose weight and maintain health.

Beauty effect of functional peptide

Functional peptide has its unique effect in beauty, such as bone glue peptide, which can significantly improve the aging related collagen synthesis and improve the skin condition; collagen peptide is rich in hydrophilic moisturizing factors, which can conserve the skin water and make the skin have good affinity and elasticity.

Application of functional peptide in food industry

The application of functional peptide in nutritional food

The functional peptide is easy to digest and absorb, and the absorption speed is fast. It can be used in the nutrition of special patients, especially in the intestinal nutrition and flow food of digestive system, in the rehabilitation patients, the elderly with digestive function decline and the infant food with immature digestive function.

Application of functional peptide in functional and health food

Functional peptide has low antigenicity function, which can be used to produce functional health food such as cholesterol reduction, blood pressure reduction, cardiovascular disease prevention, protein supply for obese patients, and non allergenic health food such as infant milk powder and dessert heart.

Application of functional peptide in common food

1. For fish, meat and other high protein products: it can highlight the meat flavor of the products, improve the freshness, improve the quality at the same time, and make them have elastic and soft texture.

2. For baking food: adding functional peptide to baking food can increase flavor and aroma, make its texture loose and taste good.

3. For candy and pastry: functional peptide is used in the production of candy and chocolate to reduce the sweetness, increase the aroma, reduce the cost and increase the content of amino acid.

4. For cold drink food: functional peptide has high water solubility, low viscosity of solution, no precipitation under acid condition, and high foaming effect, so it can be used to produce acid drink, instant solid drink, milk powder, beer, ice cream and other cold food.

3 common functional peptide editing

1. Peptide hormone

There is a kind of hormone with chemical structure belonging to polypeptide or protein, which is secreted by thalamus, hypophysis, islet of Langerhans, thymus, etc.; when the content of such hormone is increased or insufficient, it will lead to some important diseases, such as type 1 diabetes caused by common insulin deficiency. Hypophysis growth hormone deficiency causes dwarfism, growth hormone excess causes gigantism or acromegaly and so on.

Thyrotropin releasing hormone: a tripeptide separated and purified from the hypothalamus and composed only of pyroglutamate, histidine and proline. It can stimulate the pituitary to release thyrotropin. In addition, it can also stimulate the pituitary to release prolactin and promote the metabolism of catecholamine in the brain.

Somatostatin: a cyclic peptide composed of 14 amino acid residues, widely found in the brain and gastrointestinal tract. It can inhibit some hormones produced by pituitary. In addition, it can also inhibit the internal and external secretion of gastrointestinal tract, reduce the release of gastric acid and pepsin and secretion of pancreatic juice, reduce gastrointestinal peristalsis and gallbladder contraction, and reduce the blood flow velocity of portal vein. It is also an important drug for conservative treatment of gastric hemorrhage.

Other hormones belonging to peptides include insulin secreted by islets of Langerhans and Thymosin secreted by thymus.

2. Gastrointestinal peptide

Peptide hormones synthesized by gastrointestinal tract include gastrin (34 peptide), incretin (27 peptide), cholecystokinin (8 peptide), motilin (22 peptide), vasoactive intestinal peptide (28 peptide), neurotensin (13 peptide), etc. It has been proved that many gastrointestinal peptide hormones are also found in the brain and peripheral nervous system, called brain gut peptide. These peptides constantly adjust the body's reactivity to adapt to the changes of internal and external environment and ensure the health of the body. In this paper, several promising gastrointestinal peptides are introduced with examples.

Cholecystokinin: the synthetic cholecystokinin octapeptide (CCK8) has all natural activities. It can cause the contraction of gallbladder, promote the secretion of pancreatin and bicarbonate, regulate the peristalsis of intestine, excite some nerve cells of brain, and lead to anorexia.

Vasoactive intestinal peptide: straight chain 28 peptide, with relaxation of gastrointestinal smooth muscle; increase secretion of gastric acid, pepsin and pancreatic bicarbonate. It has a strong diastolic effect on systemic artery and arteriole. It can enhance the contractile force and cardiac output. It can relax the smooth muscle of bronchi and lungs. It can also promote the production and utilization of glucose in the brain. Increase body temperature, stimulate the secretion of prolactin, luteinizing hormone and growth hormone. It is a kind of peptide with great development prospect.

Neurotensin: it can reduce blood pressure, increase vascular permeability and hematocrit, promote glucagon release, inhibit insulin release, stimulate gastrointestinal tract contraction, inhibit gastric acid secretion, etc. It is also a remarkable peptide. Other valuable products are motilin and gastrin. In addition, there are neuropeptides,

atrial peptides and so on.

To sum up, peptide drugs are currently in the stage of in-depth research and extensive development. Some peptide substances have been used in clinical, such as peptide antibiotics, peptide vaccines and peptide drugs with different functions. Some of them have been developed into health care products, such as albumin polypeptide, which have significant effects on improving immunity, disease and postoperative rehabilitation.