Application of soft-shelled turtle peptide in promotion of protein absorption

Abstract

According to the application of the soft-shelled turtle peptide in promoting protein absorption, the soft-shelled turtle peptide is added into a special medical protein component for the first time, the digestion efficiency of the special medical protein component is remarkably improved, and protein absorption and utilization are promoted. The protein content of the soft-shelled turtle peptide formula product prepared by introducing the soft-shelled turtle peptide as one of protein sources of a protein component is greater than 70g / 100g, the amino acid score belongs to high-quality protein, and the true digestibility is 1.236 times that of a control group and is 1.08 times that of a basic formula without adding the soft-shelled turtle peptide.

Description

(I) Technical field

[0001] The invention relates to application of soft-shell turtle peptide in promoting protein absorption. (II) Background technology

[0002] Protein is the material basis of life, an organic macromolecule, the basic organic matter that constitutes cells, and the main bearer of life activities. Without protein, there is no life. There are many types of protein, such as whey protein, egg protein, soy protein, and brown rice protein. Protein exists in the diet of all people. The ingested protein is hydrolyzed into amino acids in the body through the digestive tract and then absorbed, and then synthesized into the protein needed by the human body. The human body protein is constantly metabolized and decomposed and then ingested through diet. The protein of a healthy human body is always in dynamic balance.

[0003] In recent years, with the change of people's diet and living habits, and the worsening of air and water pollution, most people are in a sub-healthy state, with decreased immune function and a gradual increase in the incidence of diseases such as cancer. When patients are in a diseased state, protein loss will be accelerated, and hypoproteinemia is prone to occur. Therefore, such patients should supplement high-quality protein in time.

[0004] Formulated foods for special medical purposes are specially processed and prepared to meet the special needs of people with limited food intake, digestive and absorption disorders, metabolic disorders or specific disease states for nutrients or diets. The protein component in the non-complete nutritional formula is suitable for people who need to supplement protein under specific diseases or medical conditions. The protein components of the special medical foods that have been launched are all mixed with whey protein powder and soy protein isolate or soy peptide powder in proportion, and some are added with edible flavors, additives, etc. The nutritional value of protein is often evaluated by protein content, amino acid score and digestibility utilization rate. Hydrolyzed whey protein is further enzymatically hydrolyzed on the basis of whey protein. It is a protein that is easy to digest and absorb and has high nutritional value. It is widely used in nutritional health foods, infant foods and other fields. Calcium caseinate is an ideal calcium supplement that is easily absorbed and utilized by the human body and does not require vitamin D. In addition to calcium, calcium caseinate is also rich in protein, so it is also a high-quality protein supplement source. The molecular weight of soy peptide is about 500Da, which can quickly replenish the body's nitrogen source, restore physical strength and relieve fatigue. The formula of protein components for special medical foods requires an amino acid score greater than 100. Whey protein, soy protein and casein all meet this requirement, which also promotes the application of these proteins / peptides in protein component formulas. Whey protein and soy protein isolate are both high-quality whole proteins with excellent amino acid scores, but they are slightly weaker than small molecular weight proteins such as polypeptides in terms of digestibility and absorption rate.

[0005] Compared with soy protein, soy peptide has the physiological functions of high digestion and absorption rate, rapid energy provision, lowering cholesterol, lowering blood pressure and promoting fat metabolism, as well as good processing properties such as no beany smell, no protein denaturation, no precipitation in acidity, no coagulation when heated, easy solubility in water and good fluidity. It is an excellent health food material.

[0006] Turtle peptides have rich nutritional value and multiple physiological functions. They are bioactive small molecule polypeptides with an average molecular weight of less than 1000 Daltons. They have the characteristics of low molecular weight and high biological activity. They can be directly and effectively absorbed by the human body and participate in systemic circulation. However, according to the amino acid score requirements, their essential amino acid content is low, and their use as a raw material alone does not meet the requirements of protein components. Therefore, turtle peptides are not used in the protein component formula of special medical foods. (III) Summary of the invention

[0007] The purpose of the present invention is to provide an application of a turtle peptide in promoting protein absorption. The turtle peptide can improve the digestibility and utilization rate of protein components for special medical purposes and promote protein absorption and utilization.

[0008] The technical solution adopted by the present invention is:

[0009] The invention provides application of a turtle peptide in promoting protein absorption.

[0010] The amino acid composition of the turtle peptide of the present invention is shown in Table 1. All turtle peptides with various amino acid sequences or amino acid compositions are suitable for the present invention.

[0011] Table 1 Amino acid composition of turtle peptide

[0012]

[0013] Note: * indicates essential amino acids for the human body, # indicates hydrophobic amino acids, and + indicates branched-chain amino acids

[0014] Furthermore, the application is to add the turtle peptide as a raw material into a protein component for special medical purposes.

[0015] Furthermore, the amount of turtle peptide added is 8-12%, preferably 9%, based on the mass of the protein component for special medical purposes; or 80-120 mg / g, preferably 90 mg / g, based on the mass of the protein component for special medical purposes.

[0016] The present invention also provides a special medical protein component containing turtle peptide, wherein the quality formula of the special medical protein component is: 30-50 parts of whey protein, 10-30 parts of calcium caseinate, 30-50 parts of soybean peptide, and 8-12 parts of turtle peptide.

[0017] Furthermore, the quality formula of the special medical protein component is: 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soybean peptide, and 8-12 parts of turtle peptide.

[0018] Furthermore, the quality formula of the special medical protein component is: 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soy peptide, and 9 parts of turtle peptide.

[0019] The dosage of the special medical protein component added with turtle peptide in the present invention for adults is 0.2-0.3 g / kg·day.

[0020] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0021] The present invention adds turtle peptides to the special medical protein component for the first time, significantly improving the digestion efficiency of the special medical protein component and promoting protein absorption and utilization. The turtle peptide formula product prepared by the present invention by introducing turtle peptides as one of the protein sources of the protein component has a protein content of more than 70g / 100g, an amino acid score belonging to high-quality protein, and a true digestibility of 1.236 times that of the control group, and 1.08 times that of the basic formula without adding turtle peptides. (IV) Description of the drawings

[0022] Figure 1 The protein formula design diagram is drawn in 3D with the soybean peptide addition amount (SP%) as the x-axis, the calcium caseinate addition amount (Ca-CS%) as the y-axis, and the formula amino acid score (AAS) as the z-axis. (V) Specific implementation methods

[0023] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0024] Example 1: Determination of digestibility of protein component raw materials

[0025] Ingredients: whey protein (Xi'an Bangze Biotechnology Co., Ltd.), soy peptide (Xi'an Bangze Biotechnology Co., Ltd.), calcium caseinate (Tianjin Yijianyuan Food Co., Ltd.), turtle peptide (Hangzhou Derun Quanjian Health Technology Co., Ltd.), tuna peptide (Shaanxi Yunhe Biotechnology Co., Ltd.).

[0026] Through the nitrogen metabolism test, metabolic cages were used to separate the feces and urine metabolites of the test animals, the nitrogen content of the metabolites was measured, and the digestibility and utilization rate of the protein were calculated. The specific experimental process is as follows:

[0027] Thirty-six specific pathogen free (SPF) SD rats were purchased from the Hangzhou Academy of Medical Sciences in Zhejiang Province. All of them were healthy male rats weighing 200±20g. According to the provisions of the "Experimental Animal Environment and Facilities", the experimental rats were kept in a sterile barrier environment in the Experimental Animal Center of Zhejiang University of Technology. The relative humidity in the barrier room was 45% to 55%, the temperature was 20 to 25°C, and the light was alternated between light and dark for 12 hours. Rats were kept in a cage of 5 and were free to eat and drink water. They were allowed to adapt to the environment for 5 days.

[0028] After the adaptation to the environment, the experiment entered a 4-day dietary balance period. 36 SD rats were randomly divided into 6 groups, namely, nitrogen-free group, turtle peptide group (300 mg / kg), tuna peptide group (300 mg / kg), whey protein group (300 mg / kg), calcium caseinate group (300 mg / kg), and soybean peptide group (300 mg / kg), with 6 rats in each group. Except for the rats in the nitrogen-free group, the other 5 groups were gavaged once a day at a dose of 10 mL / kg, and the solution preparation solvent was pure water. The rats in the nitrogen-free group were gavaged with an equal volume of pure water every day. During the dietary balance period, the experimental animals were provided with sufficient drinking water, and the daily feed amount per mouse was limited to 15 g, and was delivered at the same time every day. In terms of feed, the nitrogen-free group was fed with a specific protein-free feed, and each mouse was fed 15 g of feed per day, and the other 5 groups used ordinary feed.

[0029] After the dietary balance period, a 5-day metabolic experiment period began. The experimental rats were transferred to separate metabolic cages. The daily feed intake and remaining amount of each rat were recorded daily. The metabolites of the rats were collected during the 5-day metabolic experiment. The feces were collected using a 50mL centrifuge tube, and the metabolite separation funnel was rinsed with a 0.5mol / L sulfuric acid solution. The rinse solution was combined with urine and stored. After the surface of the feces was initially dried, impurities were removed. After drying to constant weight, the total weight was recorded. The fecal particles were ground and crushed using a mortar and collected in a sealed container for testing. After filtering impurities from the urine, 0.5mol / L sulfuric acid was used to dilute the volume to 100mL, and it was also collected in a sealed container for testing. The nitrogen content of metabolites was determined using the Kjeldahl method.

[0030] Substitute the measured nitrogen content into the following formula to obtain the apparent digestibility, true digestibility, biological value, and net utilization rate of protein to evaluate the nutritional value of protein raw materials. The nitrogen intake includes nitrogen intake from feed and gavage, the fecal nitrogen in the nitrogen-free group is metabolic nitrogen, and the urinary nitrogen in the nitrogen-free group corresponds to endogenous nitrogen.

[0031] Protein apparent digestibility (%) = (nitrogen intake - fecal nitrogen) / nitrogen intake * 100%

[0032] True protein digestibility = [intake nitrogen - (fecal nitrogen - fecal metabolic nitrogen)] / food nitrogen × 100%

[0033] Biological value BV = [food N - (fecal N - metabolic N) - (urine N - endogenous N)] / [food N - (fecal N - metabolic N)] * 100% Net protein utilization NPU = [food N - (fecal N - metabolic N) - (urine N - endogenous N)] / food N * 100%

[0034] Table 2. Results of digestibility and utilization of protein component raw materials

[0035]

[0036] The results in Table 2 show that each protein raw material has excellent digestion and absorption efficiency.

[0037] Example 2: Design of protein formula and detection of protein digestibility

[0038] 1. Basic formula

[0039] (1) Design of basic formula

[0040] A basic protein formula was designed using the whey protein, soy peptide, and calcium caseinate combination in Example 1. Existing literature often reports that animal and plant protein compounding has higher nutritional value, and the animal and plant protein compounding ratio varies from 1:1 to 2:1, thereby limiting the mass addition of soy peptide to 30-50%, and calcium caseinate as a high-quality protein and high-quality additive to a mass addition of 10-30%, and the specific formula is shown in Table 3.

[0041] Table 3. Basic formula and amino acid score

[0042]

[0043] (2) Detection of amino acid score of basic formula

[0044] Table 4. Amino acid scores of protein component raw materials

[0045]

[0046] The essential amino acid composition of the three protein raw materials was determined (Table 4), and the essential amino acid content of each raw material was substituted into the following formula to calculate the formula amino acid score (Table 3).

[0047] Formula amino acid score = [amino acid content in whey protein (mg / g) * whey protein addition % + amino acid content in soy peptide protein (mg / g) * soy peptide addition % + amino acid content in calcium caseinate protein (mg / g) * calcium caseinate addition %] / [corresponding essential amino acid content in FAO scoring standard model (mg / g)]

[0048] According to the formula amino acid scores of the three protein raw materials at different addition amounts, the data were plotted into an intuitive 3D graph using Origin drawing software, with the soybean peptide addition amount (SP%) as the x-axis, the calcium caseinate addition amount (Ca-CS%) as the y-axis, and the formula amino acid score (AAS) as the z-axis. The results are shown in Figure 1 .

[0049] like Figure 1 As shown in Table 3, when the addition of soy peptide exceeds 38%, the formula amino acid score value drops rapidly, which determines that the addition of soy peptide in the formula should not be greater than 40%. When the addition of calcium caseinate is greater than 18%, the rate of increase of the amino acid score tends to be flat. The change in the amino acid score determines that 38% protein is provided by soy peptide, 18% protein is provided by calcium caseinate, and 44% protein is provided by whey protein per gram of protein formula. The animal protein: plant protein of this formula is ≈2:1, which meets the compound ratio of high-quality animal and plant proteins. The amino acid score of this formula meets the requirements of high-quality protein, and the protein content is greater than 70g / 100g.

[0050] 2. Turtle peptide protein formula

[0051] Turtle peptide is added to the already compounded high-quality protein ratio components. Considering that the limiting amino acid of turtle peptide is tryptophan, it is finally determined that the amount of active peptide added is 10% protein per gram of protein formula, and the remaining 90% protein is provided by whey protein, calcium caseinate and soy peptide, and the addition ratio of the three remains unchanged. The final formula consists of 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soy peptide, and 9 parts of turtle peptide. The amino acid score of this formula is greater than 100 points, and the protein content is greater than 70g / 100g, which is a high-quality protein formula.

[0052] 3. Tuna peptide protein formula

[0053] Tuna peptides are added to the already compounded high-quality protein ratio components. According to the turtle peptide formula addition ratio, it is finally determined that the amount of tuna peptide added is 10% protein per gram of protein formula, and the remaining 90% protein is provided by whey protein, calcium caseinate and soy peptides, and the addition ratio of the three remains unchanged. The final formula consists of 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soy peptides, and 9 parts of tuna peptides. The amino acid score of this formula is greater than 100 points, and the protein content is greater than 70g / 100g, which is also a high-quality protein formula.

[0054] 4. Digestibility

[0055] The digestibility of the basic formula, turtle peptide formula, tuna peptide formula and control group was detected by the method of Example 1. The control group was pure water. The results are shown in Table 5 below.

[0056] Table 5. Digestibility of protein component formula

[0057]

[0058] Note: Compared with the control group, **P<0.01, ****P<0.0001.

[0059] Table 5 shows that the true digestibility of the turtle peptide formula is 1.236 times that of the control group and 1.08 times that of the basic formula without turtle peptide, which has a high digestibility. The apparent digestibility, true digestibility and net utilization rate of the turtle peptide formula are higher than those of the basic formula group without turtle peptide and the tuna formula group with tuna peptide added in the same proportion as turtle peptide.

Claims

1. Application of soft-shell turtle peptide in promoting protein absorption.

2. The use according to claim 1, characterized in that The application is to add the turtle peptide as a raw material into a protein component for special medical purposes.

3. The use according to claim 2, characterized in that The amount of turtle peptide added is 8-12% based on the mass of the protein component for special medical purposes.

4. A special medical protein component containing the soft-shelled turtle peptide according to claim 1.

5. The special medical protein component according to claim 4, characterized in that: The quality formula of the special medical protein component is: 30-50 parts of whey protein, 10-30 parts of calcium caseinate, 30-50 parts of soybean peptide, and 8-12 parts of turtle peptide.

6. The special medical protein component according to claim 5, characterized in that: Special medical protein component quality formula: 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soy peptide, 8-12 parts of turtle peptide.

7. The special medical protein component according to claim 6, characterized in that: Special medical protein component quality formula: 45 parts of whey protein, 16 parts of calcium caseinate, 30 parts of soy peptide, and 9 parts of turtle peptide.

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